Updated on 2022/11/28

写真a

 
NAKAGAWA, Kento
 
Scopus Paper Info  
Paper Count: 0  Citation Count: 0  h-index: 8

Citation count denotes the number of citations in papers published for a particular year.

Affiliation
Faculty of Sport Sciences, School of Sport and Sciences
Job title
Assistant Professor(without tenure)

Research Experience

  • 2018.04
    -
    2019.03

    日本学術振興会 海外特別研究員 (Toronto Rehabilitation Institute)

  • 2015.04
    -
    2018.03

    日本学術振興会   特別研究員 PD (東京大学)

  • 2014.04
    -
    2015.03

    Waseda University   Faculty of Sport Sciences

  • 2012.04
    -
    2014.03

    日本学術振興会 特別研究員 DC2 (早稲田大学)

Professional Memberships

  •  
     
     

    JAPAN SOCIETY OF PHYSICAL EDUCATION, HEALTH AND SPORT SCIENCES

  •  
     
     

    THE JAPANESE SOCIETY OF PHYSICAL FITNESS AND SPORTS MEDICINE

  •  
     
     

    EUROPEAN COLLEGE OF SPORT SCIENCE

  •  
     
     

    THE JAPANESE SOCIETY FOR MOTOR CONTROL

  •  
     
     

    SOCIETY FOR NEUROSCIENCE

 

Research Areas

  • Sports sciences

  • Neuroscience-general

  • Rehabilitation science

Papers

  • アスリートや障がい者における神経可塑性と ニューロモジュレーションによる機能向上

    中川剣人

    バイオメカニズム学会誌    2023.02  [Invited]

    Authorship:Lead author, Corresponding author

  • Neuromuscular recruitment pattern in motor point stimulation

    Kento Nakagawa, Kai Lon Fok, Kei Masani

    Artificial Organs   in press  2022.10  [Refereed]

    DOI

    Scopus

  • Differences in the recruitment properties of the corticospinal pathway between the biceps femoris and rectus femoris muscles.

    Ayako Higashihara, Kento Nakagawa, Genki Futatsubashi, Hirofumi Sekiguchi, Yasuharu Nagano, Norikazu Hirose

    Brain research     147963 - 147963  2022.06  [Refereed]  [International journal]

     View Summary

    The neuromuscular activity in the hamstring and quadriceps muscles is vital for rapid force control during athletic movements. This study aimed to investigate the recruitment properties of the corticospinal pathway of the biceps femoris long head (BFlh) and rectus femoris (RF) muscles. Thirty-two male subjects were participated in this study. Corticospinal excitability was investigated for BFlh and RF during the isometric knee flexion and extension tasks, respectively, using transcranial magnetic stimulation. A sigmoidal relationship was observed between the stimulus intensity and amplitude of motor-evoked potentials and characterized by a plateau value, maximum slope, and threshold. Compared with RF, BFlh had a significantly lower plateau value (P < 0.001, d = 1.17), maximum slope (P < 0.001, r = 0.79), and threshold (P = 0.003, d = 0.62). The results showed that the recruitment properties of the corticospinal pathway significantly differ between BFlh and RF. These results reveal that when a sudden large force is required during athletic movements, the RF can produce force through a rapid increase in the recruitment of motor units. The BFlh, on the other hand, requires larger or more synchronized motor commands for enabling the proper motor unit behavior to exert large forces. These differences in the neurophysiological factors between the hamstrings and quadriceps can have a substantial effect on the balance of force generation during athletic activities.

    DOI PubMed

    Scopus

  • Development of a Coaching System for Functional Electrical Stimulation Rowing: A Feasibility Study in Able-Bodied Individuals.

    Shirin Tajali, Kai Lon Fok, Pirashanth Theventhiran, Gongkai Ye, Hikaru Yokoyama, Kento Nakagawa, Kei Masani

    Sensors (Basel, Switzerland)   22 ( 5 )  2022.02  [Refereed]  [International journal]

     View Summary

    BACKGROUND: Functional electrical stimulation (FES) during rowing has substantial effects on cardiovascular health in individuals with spinal cord injuries. Currently, manual stimulation control where stimulation is operated by rowers is mostly utilized. However, it takes time to obtain the skill to initiate FES at the optimal timing. The purpose of this study was to develop a coaching system that helps rowers to initiate FES at the optimal timing. METHODS: The optimal range for FES application was identified based on the electromyography of the left quadriceps in 10 able-bodied individuals (AB). Then, the effects of the coaching system on the timing of button-pressing, power, and work were investigated in 7 AB. RESULTS: Vastus lateralis (VL) activation began consistently before the seat reached the anterior-most position. Therefore, seat position at the onset of VL was used as the variable to control the switch timing in the coaching system. The results revealed significantly higher power and work outputs in the coaching than the no-coaching condition (median power coaching: 19.10 W, power no-coaching: 16.48 W, p = 0.031; median work coaching: 109.74 J, work no-coaching: 65.25 J, p = 0.047). CONCLUSIONS: The coaching system can provide the optimal timing for FES, resulting in improved performance.

    DOI PubMed

    Scopus

  • Dynamic Control of Upper Limb Stretch Reflex in Wrestlers

    SHO ITO, KENTO NAKAGAWA, TSUYOSHI NAKAJIMA, MISAKI ITEYA, LARRY CRAWSHAW, KAZUYUKI KANOSUE

    Medicine & Science in Sports & Exercise   54 ( 2 ) 313 - 320  2022.02  [Refereed]

    DOI

  • Difference in gaze control ability between low and high skill players of a real-time strategy game in esports.

    Inhyeok Jeong, Kento Nakagawa, Rieko Osu, Kazuyuki Kanosue

    PloS one   17 ( 3 ) e0265526  2022  [International journal]

    Authorship:Corresponding author

     View Summary

    This research investigated the difference in aspects of gaze control between esports experts (Expert) and players with lower skills (Low Skill) while playing the real-time strategy game called StarCraft. Three versions of this game at different difficulty levels were made with the StarCraft Editor, and the gaze movements of seven Expert and nine Low Skill players were analyzed while they played the games. The gaze of Expert players covered a significantly larger area in the horizontal direction than the gaze of Low Skill players. Furthermore, the magnitude and number of saccadic eye movements were greater, and saccade velocity was faster in the Expert than in the Low Skill players. In conclusion, StarCraft experts have a specific gaze control ability that enables them to quickly and widely take visual information from all over the monitor. This could be one of the factors enabling StarCraft experts to perform better than players with lower skills when playing games that require task-switching ability.

    DOI PubMed

    Scopus

    1
    Citation
    (Scopus)
  • Increase in foot arch asymmetry after full marathon completion

    Mako Fukano, Kento Nakagawa, Takayuki Inami, Ayako Higashihara, Satoshi Iizuka, Takaya Narita, Toshihiro Maemichi, Akane yoshimura, Shota Yamaguchi, Shigeo Iso

    Journal of Sports Sciences   39 ( 21 ) 2468 - 2474  2021.11  [Refereed]  [International journal]

     View Summary

    Long-distance running results in lowering of the foot medial longitudinal arch, but it is unknown whether the left and right arches decrease equally. This study aimed to determine whether foot arch asymmetry increases upon completion of a full marathon and to identify factors capable of explaining the degree of asymmetry of navicular height and navicular height displacement. The three-dimensional foot posture data of 74 collegiate runners were obtained using an optical foot scanner system before (PRE) and immediately after (POST) a full marathon. The navicular height and arch height ratio (normalised navicular height by foot length) of both feet significantly decreased from PRE to POST full marathon completion (44.3 ± 6.3 mm versus 40.8 ± 6.5 mm, 17.8 ± 2.5 versus 16.6 ± 2.7, respectively; p < 0.001, both). The asymmetry of the arch height ratio was significantly greater POST than PRE marathon. Multiple linear regression analysis indicated that the POST-race Asymmetry Index (AI) of navicular height was significantly predicted by the PRE-race AI of navicular height; navicular height displacement was predicted by PRE-race navicular height and the marathon time. Full marathon running induced increasing asymmetry and lowering of the medial longitudinal arch in runners.

    DOI PubMed

    Scopus

  • Para-Sports can Promote Functional Reorganization in the Ipsilateral Primary Motor Cortex of Lower Limbs Amputee

    Tomoya Nakanishi, Nobuaki Mizuguchi, Kento Nakagawa, Kimitaka Nakazawa

    Neurorehabilitation and Neural Repair     154596832110566 - 154596832110566  2021.11  [Refereed]

     View Summary

    Background. Drastic functional reorganization was observed in the ipsilateral primary motor cortex (M1) of a Paralympic long jumper with a unilateral below-knee amputation in our previous study. However, it remains unclear whether long-term para-sports are associated with ipsilateral M1 reorganization since only 1 athlete with amputation was investigated. Objective. This study aimed to investigate the relationship between the long-term para-sports and ipsilateral M1 reorganization after lower limb amputation. Methods. Lower limb rhythmic muscle contraction tasks with functional magnetic resonance imaging and T1-weighted structural imaging were performed in 30 lower limb amputees with different para-sports experiences in the chronic phase. Results. Brain activity in the ipsilateral primary motor and somatosensory areas (SM1) as well as the contralateral dorsolateral prefrontal cortex, SM1, and inferior temporal gyrus showed a positive correlation with the years of routine para-sports participation (sports years) during contraction of the amputated knee. Indeed, twelve of the 30 participants who exhibited significant ipsilateral M1 activation during amputated knee contraction had a relatively longer history of para-sports participation. No significant correlation was found in the structural analysis. Conclusions. Long-term para-sports could lead to extensive reorganization at the brain network level, not only bilateral M1 reorganization but also reorganization of the frontal lobe and visual pathways. These results suggest that the interaction of injury-induced and use-dependent cortical plasticity might bring about drastic reorganization in lower limb amputees.

    DOI

    Scopus

    1
    Citation
    (Scopus)
  • Intra-limb modulations of posterior root-muscle reflexes evoked from the lower-limb muscles during isometric voluntary contractions

    Akira Saito, Kento Nakagawa, Yohei Masugi, Kimitaka Nakazawa

    Experimental Brain Research   239 ( 10 ) 3035 - 3043  2021.10  [Refereed]

     View Summary

    Abstract

    Although voluntary muscle contraction modulates spinal reflex excitability of contracted muscles and other muscles located at other segments within a limb (i.e., intra-limb modulation), to what extent corticospinal pathways are involved in intra-limb modulation of spinal reflex circuits remains unknown. The purpose of the present study was to identify differences in the involvement of corticospinal pathways in intra-limb modulation of spinal reflex circuits among lower-limb muscles during voluntary contractions. Ten young males performed isometric plantar-flexion, dorsi-flexion, knee extension, and knee flexion at 10% of each maximal torque. Electromyographic activity was recorded from soleus, tibialis anterior, vastus lateralis, and biceps femoris muscles. Motor evoked potentials and posterior root-muscle reflexes during rest and isometric contractions were elicited from the lower-limb muscles using transcranial magnetic stimulation and transcutaneous spinal cord stimulation, respectively. Motor evoked potential and posterior root-muscle reflex amplitudes of soleus during knee extension were significantly increased compared to rest. The motor evoked potential amplitude of biceps femoris during dorsi-flexion was significantly increased, whereas the posterior root-muscle reflex amplitude of biceps femoris during dorsi-flexion was significantly decreased compared to rest. These results suggest that corticospinal and spinal reflex excitabilities of soleus are facilitated during knee extension, whereas intra-limb modulation of biceps femoris during dorsi-flexion appeared to be inverse between corticospinal and spinal reflex circuits.

    DOI

    Scopus

    1
    Citation
    (Scopus)
  • Specific Brain Reorganization Underlying Superior Upper Limb Motor Function After Spinal Cord Injury: A Multimodal MRI Study

    Tomoya Nakanishi, Kento Nakagawa, Hirofumi Kobayashi, Kazutoshi Kudo, Kimitaka Nakazawa

    Neurorehabilitation and Neural Repair   35 ( 3 ) 220 - 232  2021.03  [Refereed]

     View Summary

    Background

    We recently discovered that individuals with complete spinal cord injury (SCI) have a higher grip force control ability in their intact upper limbs than able-bodied subjects. However, the neural basis for this phenomenon is unknown.

    Objective

    This study aimed to investigate the neural basis of the higher grip force control in the brains of individuals with SCI using multimodal magnetic resonance imaging (MRI).

    Methods

    Eight SCI subjects and 10 able-bodied subjects performed hand grip force control tasks at 10%, 20%, and 30% of their maximal voluntary contraction during functional MRI (fMRI). Resting-state fMRI and T1-weighted structural images were obtained to investigate changes in brain networks and structures after SCI.

    Results

    SCI subjects showed higher grip force steadiness than able-bodied subjects ( P &lt; .05, corrected), smaller activation in the primary motor cortex ( P &lt; .05, corrected), and deactivation of the visual cortex ( P &lt; .001, uncorrected). Furthermore, SCI subjects had stronger functional connectivity between the superior parietal lobule and the left primary motor cortex ( P &lt; .001, uncorrected), as well as larger gray matter volume in the bilateral superior parietal lobule ( P &lt; .001, uncorrected).

    Conclusions

    The structural and functional reorganization observed in the superior parietal lobule of SCI subjects may represent the neural basis underlying the observed higher grip force control, and is likely responsible for the smaller activation in the primary motor cortex observed in these individuals. These findings could have applications in the fields of neurorehabilitation for improvement of intact limb functions after SCI.

    DOI

    Scopus

    4
    Citation
    (Scopus)
  • Inter-muscle differences in modulation of motor evoked potentials and posterior root-muscle reflexes evoked from lower-limb muscles during agonist and antagonist muscle contractions

    Akira Saito, Kento Nakagawa, Yohei Masugi, Kimitaka Nakazawa

    Experimental Brain Research   239 ( 2 ) 463 - 474  2021.02  [Refereed]

     View Summary

    <title>Abstract</title>Voluntary contraction facilitates corticospinal and spinal reflex circuit excitabilities of the contracted muscle and inhibits spinal reflex circuit excitability of the antagonist. It has been suggested that modulation of spinal reflex circuit excitability in agonist and antagonist muscles during voluntary contraction differs among lower-limb muscles. However, whether the effects of voluntary contraction on the excitabilities of corticospinal and spinal reflex circuits depend on the tested muscles remains unknown. The purpose of this study was to examine inter-muscle differences in modulation of the corticospinal and spinal reflex circuit excitabilities of multiple lower-limb muscles during voluntary contraction. Eleven young males performed isometric plantar-flexion, dorsi-flexion, knee extension, and flexion at low torque levels. Motor evoked potentials (MEPs) and posterior root-muscle reflexes from seven lower-leg and thigh muscles were evoked by transcranial magnetic stimulation and transcutaneous spinal cord stimulation, respectively, at rest and during weak voluntary contractions. MEP and posterior root-muscle reflex amplitudes of agonists were significantly increased as agonist torque level increased, except for the reflex of the tibialis anterior. MEP amplitudes of antagonists were significantly increased in relation to the agonist torque level, but those of the rectus femoris were slightly depressed during knee flexion. Regarding the posterior root-muscle reflex of the antagonists, the amplitudes of triceps surae and the hamstrings were significantly decreased, but those of the quadriceps femoris were significantly increased as the agonist torque level increased. These results demonstrate that modulation of corticospinal and spinal reflex circuit excitabilities during agonist and antagonist muscle contractions differed among lower-limb muscles.

    DOI PubMed

    Scopus

    3
    Citation
    (Scopus)
  • Determinants of Neural Plastic Changes Induced by Motor Practice

    Wen Dai, Kento Nakagawa, Tsuyoshi Nakajima, Kazuyuki Kanosue

    Frontiers in Human Neuroscience   15  2021.01  [Refereed]

     View Summary

    Short-term motor practice leads to plasticity in the primary motor cortex (M1). The purpose of this study is to investigate the factors that determine the increase in corticospinal tract (CST) excitability after motor practice, with special focus on two factors; “the level of muscle activity” and “the presence/absence of a goal of keeping the activity level constant.” Fifteen healthy subjects performed four types of rapid thumb adduction in separate sessions. In the “comfortable task” (C) and “forceful task” (F), the subjects adducted their thumb using comfortable and strong forces. In the “comfortable with a goal task” (CG) and “forceful with a goal task” (FG), subjects controlled the muscle activity at the same level as in the C and F, respectively, by adjusting the peak electromyographic amplitude within the target ranges. Paired associative stimulation (PAS), which combines peripheral nerve (median nerve) stimulation and transcranial magnetic stimulation (TMS), with an inter-stimulus interval of 25 ms (PAS25) was also done. Before and after the motor tasks and PAS25, TMS was applied to the M1. None of the four tasks showed any temporary changes in behavior, meaning no learning occurred. Motor-evoked potential (MEP) amplitude increased only after the FG and it exhibited a positive correlation with the MEP increase after PAS25, suggesting that FG and PAS25 share at least similar plasticity mechanisms in the M1. Resting motor threshold (RMT) decreased only after FG, suggesting that FG would also be associated with the membrane depolarization of M1 neurons. These results suggest task-dependent plasticity from the synergistic effect of forceful muscle activity and of setting a goal of keeping the activity level constant.

    DOI

    Scopus

  • Motor Point Stimulation in Spinal Paired Associative Stimulation can Facilitate Spinal Cord Excitability

    Kai Lon Fok, Naotsugu Kaneko, Atsushi Sasaki, Kento Nakagawa, Kimitaka Nakazawa, Kei Masani

    Front Hum Neurosci   14   593806 - 593806  2020.11  [Refereed]  [International journal]

     View Summary

    Paired associative stimulation at the spinal cord (spinal PAS) has been shown to increase muscle force and dexterity by strengthening the corticomuscular connection, through spike timing dependent plasticity. Typically, transcranial magnetic stimulation (TMS) and transcutaneous peripheral nerve electrical stimulation (PNS) are often used in spinal PAS. PNS targets superficial nerve branches, by which the number of applicable muscles is limited. Alternatively, a muscle can be activated by positioning the stimulation electrode on the “motor point” (MPS), which is the most sensitive location of a muscle to electrical stimulation. Although this can increase the number of applicable muscles for spinal PAS, nobody has tested whether MPS can be used for the spinal PAS to date. Here we investigated the feasibility of using MPS instead of PNS for spinal PAS. Ten healthy male individuals (26.0 ± 3.5 yrs) received spinal PAS on two separate days with different stimulation timings expected to induce (1) facilitation of corticospinal excitability (REAL) or (2) no effect (CONTROL) on the soleus. The motor evoked potentials (MEP) response curve in the soleus was measured prior to the spinal PAS, immediately after (0 min) and at 10, 20, 30 min post-intervention as a measure of corticospinal excitability. The post-intervention MEP response curve areas were larger in the REAL condition than the CONTROL conditions. Further, the post-intervention MEP response curve areas were significantly larger than pre-intervention in the REAL condition but not in the CONTROL condition. We conclude that MPS can facilitate corticospinal excitability through spinal PAS.

    DOI PubMed

    Scopus

    2
    Citation
    (Scopus)
  • 下肢切断後の運動経験と運動関連脳領域構造・機能的再組織化の関連

    中西 智也, 水口 暢章, 中川 剣人, 星野 元訓, 中澤 公孝

    日本義肢装具学会誌   36 ( 特別 ) 169 - 169  2020.09  [Refereed]

  • Motor point stimulation primarily activates motor nerve

    Kento Nakagawa, Austin J. Bergquist, Taro Yamashita, Takashi Yoshida, Kei Masani

    Neuroscience Letters   736   135246 - 135246  2020.09  [Refereed]

    DOI

    Scopus

    6
    Citation
    (Scopus)
  • Regional differences in hamstring muscle damage after a marathon

    Higashihara A, Nakagawa K, Inami T, Fukano M, Iizuka S, Maemichi T, Hashizume S, Narita T, Hirose N.

    PLOS ONE   15 ( 6 ) e0234401 - e0234401  2020.06  [Refereed]

    DOI

    Scopus

    2
    Citation
    (Scopus)
  • b

      印刷中  2020  [Refereed]

  • Cortical reorganization of lower-limb motor representations in an elite archery athlete with congenital amputation of both arms

    Kento Nakagawa, Mitsuaki Takemi, Tomoya Nakanishi, Atsushi Sasaki, Kimitaka Nakazawa

    NeuroImage: Clinical   25   102144 - 102144  2020.01  [Refereed]

    DOI

    Scopus

    12
    Citation
    (Scopus)
  • Remarkable hand grip steadiness in individuals with complete spinal cord injury

    Nakanishi T, Kobayashi H, Obata H, Nakagawa K, Nakazawa K

    Exp Brain Res   237 ( 12 ) 3175 - 3183  2019.12  [Refereed]

    DOI

    Scopus

    4
    Citation
    (Scopus)
  • a

      18 ( 2 ) 42 - 47  2019.12  [Refereed]

  • Tracking of Time-Dependent Changes in Muscle Hardness After a Full Marathon.

    Takayuki Inami, Kento Nakagawa, Takahisa Yonezu, Mako Fukano, Ayako Higashihara, Satoshi Iizuka, Taira Abe, Takaya Narita

    Journal of strength and conditioning research   33 ( 12 ) 3431 - 3437  2019.12  [Refereed]  [International journal]

     View Summary

    Inami, T, Nakagawa, K, Yonezu, T, Fukano, M, Higashihara, A, Iizuka, S, Abe, T, and Narita, T. Tracking of time-dependent changes in muscle hardness after a full marathon. J Strength Cond Res 33(12): 3431-3437, 2019-We sought to identify changes in individual muscle hardness after a full marathon and to track time-dependent changes using ultrasound strain elastography (SE). Twenty-one collegiate marathon runners were recruited. Muscle hardness (i.e., strain ratio, SR) was measured using SE for the rectus femoris (RF), vastus lateralis (VL), biceps femoris (BF) long head, tibialis anterior (TA), gastrocnemius medial (GM) head, and soleus (SOL) muscles at the following time points: pre (PRE), immediately post (POST), day-1 (D1), day-3 (D3), and day-8 (D8), after a full marathon. We found that the SR decreased after the full marathon (i.e., the muscle became harder), and that the lowest SR across all measured muscles was observed on D1. Although there was no difference in the magnitude of change in SR between the muscles of the thigh, that of the MG and SOL were significantly larger than that of the TA. Muscle hardness in the vastus lateralis, biceps femoris, and SOL recovered at D8 (i.e., nonsignificant difference from PRE), whereas recovery of rectus femoris and gastrocnemius medial hardness at D8 was not observed. Thus, the degree of change in muscle hardness does not occur uniformly within the lower extremity muscles. In particular, changes in muscle hardness of the TA after a full marathon are small compared with other muscles and time-dependent changes in each muscle vary during recovery. The features of muscle hardness identified in this study will be useful for coaches when mentoring runners on proper forms and for training advisers and therapists who seek to address deficiencies in running.

    DOI PubMed

    Scopus

    6
    Citation
    (Scopus)
  • Accuracy in Pinch Force Control Can Be Altered by Static Magnetic Field Stimulation Over the Primary Motor Cortex

    Kento Nakagawa, Atsushi Sasaki, Kimitaka Nakazawa

    Neuromodulation: Technology at the Neural Interface   22 ( 8 ) 871 - 876  2019.12  [Refereed]

    DOI

    Scopus

    8
    Citation
    (Scopus)
  • Changes in muscle hardness after a full marathon appear different even intramuscularly

    Takayuki Inami, Kento Nakagawa, Mako Fukano, Takahisa Yonezu, Ayako Higashihara, Satoshi Iizuka, Takaya Narita, Mitsuyoshi Murayama

    Journal of Sports Medicine and Physical Fitness   59 ( 6 ) 1094 - 1096  2019.11  [Refereed]

    DOI PubMed

    Scopus

  • フルマラソンにおける身体衝撃の経時変化

    永野 康治, 東原 綾子, 中川 剣人, 成田 崇矢, 稲見 崇孝

    理学療法学   46 ( Suppl.1 ) P1 - 2  2019.08

  • Functional plasticity of the ipsilateral primary sensorimotor cortex in an elite long jumper with below-knee amputation

    Mizuguchi N*, Nakagawa K*, Tazawa Y, Kanosue K, Nakazawa K, *Equal contribution

    Neuroimage Clin   23   101847  2019.05  [Refereed]

    DOI

    Scopus

    9
    Citation
    (Scopus)
  • Repeatability of spinal reflexes of lower limb muscles evoked by transcutaneous spinal cord stimulation.

    Akira Saito, Yohei Masugi, Kento Nakagawa, Hiroki Obata, Kimitaka Nakazawa

    PloS one   14 ( 4 ) e0214818  2019.04  [Refereed]  [International journal]

     View Summary

    Transcutaneous electrical stimulation is a relatively new technique to evoke spinal reflexes in lower limb muscles. The advantage of this technique is that the spinal reflex responses can be obtained from multiple lower limb muscles simultaneously. However, repeatability of spinal reflexes evoked by transcutaneous spinal cord stimulation between days has not been evaluated. We aimed to examine repeatability of recruitment properties of the spinal reflexes evoked by transcutaneous spinal cord stimulation. Recruitment curves of the spinal reflexes evoked by transcutaneous spinal cord stimulation of 8 lower limb muscles (i.e., foot, lower leg, and thigh muscles) of 20 males were measured on two consecutive days. To confirm that responses were caused by activation of the sensory fiber, a double-pulse stimulation with 50 ms inter-pulse interval was delivered. Peak-to-peak amplitude of the first response was calculated for each muscle when no response was observed in the second response owing to post-activation depression. For comparison with the spinal reflexes evoked by transcutaneous spinal cord stimulation, the recruitment curves of the H-reflex amplitude of the soleus of 9 males were measured. Threshold intensity and maximal slope of the recruitment curves were calculated, and inter-day repeatability of the properties was quantified using intraclass correlation coefficients. For the spinal reflexes evoked by transcutaneous spinal cord stimulation, the intraclass correlation coefficient values of threshold intensity and maximal slope for each muscle ranged from 0.487 to 0.874 and from 0.471 to 0.964, respectively. Regarding the soleus H-reflex, the intraclass correlation coefficients of threshold intensity and maximal slope were 0.936 and 0.751, respectively. The present data showed that repeatability of the recruitment properties of the spinal reflexes evoked by transcutaneous spinal cord stimulation in the lower limb was moderate to high. Measurement of the spinal reflexes evoked by transcutaneous spinal cord stimulation would be useful for longitudinal neurophysiological studies.

    DOI PubMed

    Scopus

    7
    Citation
    (Scopus)
  • Foot posture alteration and recovery following a full marathon run

    Mako Fukano, Takayuki Inami, Kento Nakagawa, Takaya Narita, Shigeo Iso

    European Journal of Sport Science   18 ( 10 ) 1338 - 1345  2018.11  [Refereed]

    DOI

    Scopus

    7
    Citation
    (Scopus)
  • Effect of salient points in movements on the constraints in bimanual coordination

    Yan Zheng, Tetsuro Muraoka, Kento Nakagawa, Kouki Kato, Kazuyuki Kanosue

    Experimental Brain Research   236 ( 5 ) 1461 - 1470  2018.05  [Refereed]

     View Summary

    The relative-salience hypothesis has been proposed as a possible explanation for the stability of bimanual coordination. This explanation proceeds from a psychological viewpoint and is based on the following tenets: (1) cyclic joint motions involving two movements are conceived of as a unified event, (2) if a “single” point in each movement is seen as the most salient, the salient points of the two movements prefer to go together, and (3) in other cases, a unified event will be constrained by movement direction. In this investigation, we examined whether the relative-salience hypothesis could predict the type of constraint (i.e., action coupling vs movement direction) for various bimanual coordination movements. Participants performed six different joint movements in synchrony with metronome beats. Both index finger flexion/extension and forearm pronation/supination had a “single” salient point (JMsingleSP), the others had “two” salient points (JMtwoSP). Then, we applied the relative-salience hypothesis to four bimanual coordinations. The coupling of simultaneous forearm pronation was more stable than alternate pronation. Similarly, the coupling of finger flexion and forearm pronation was more stable than that of finger flexion and forearm supination. For the coordination of radial flexion/ulnar flexion and index finger flexion/extension as well as forearm pronation/supination and radial flexion/ulnar flexion, symmetric movements were more stable than asymmetric movements. The results indicated that the stability of bimanual coordination was predominantly constrained by coupling of salient points when using two JMsingleSP and it was predominantly constrained by movement direction when coordinating JMsingleSP and JMtwoSP. Thus, the relative-salience hypothesis was supported.

    DOI

    Scopus

    3
    Citation
    (Scopus)
  • Influence of motor imagery on spinal reflex excitability of multiple muscles

    Kento Nakagawa, Yohei Masugi, Akira Saito, Hiroki Obata, Kimitaka Nakazawa

    Neuroscience Letters   668   55 - 59  2018.03  [Refereed]

     View Summary

    The effects of motor imagery on spinal reflexes such as the H-reflex are unclear. One reason for this is that the muscles that can be used to record spinal reflexes are limited to traditional evoking methods Recently, transcutaneous spinal cord stimulation has been used for inducing spinal reflexes from multiple muscles and we aimed to examine the effect of motor imagery on spinal reflexes from multiple muscles. Spinal reflexes evoked by transcutaneous spinal cord stimulation were recorded from six muscles from lower limbs during motor imagery of right wrist extension and ankle plantarflexion with maximum isometric contraction. During both imaginary tasks, facilitation of spinal reflexes was detected in the ankle ipsilateral plantarflexor and dorsiflexor muscles, but not in thigh, toe or contralateral lower limb muscles. These results suggest that motor imagery of isometric contraction facilitates spinal reflex excitability in muscles of the ipsilateral lower leg and the facilitation does not correspond to the imaginary involved muscles.

    DOI

    Scopus

    7
    Citation
    (Scopus)
  • Static magnetic field stimulation applied over the cervical spinal cord can decrease corticospinal excitability in finger muscle

    Nakagawa K, Nakazawa K

    Clin Neurophysiol Pract   3   49 - 53  2018.02  [Refereed]

    DOI

    Scopus

    6
    Citation
    (Scopus)
  • Unstable rocker shoes promote recovery from marathon-induced muscle damage in novice runners

    K. Nakagawa, T. Inami, T. Yonezu, Y. Kenmotsu, T. Narita, Y. Kawakami, K. Kanosue

    Scandinavian Journal of Medicine and Science in Sports   28 ( 2 ) 621 - 629  2018.02  [Refereed]

     View Summary

    We recently reported that wearing unstable rocker shoes (Masai Barefoot Technology: MBT) may enhance recovery from marathon race-induced fatigue. However, this earlier study only utilized a questionnaire. In this study, we evaluated MBT utilizing objective physiological measures of recovery from marathon-induced muscle damages. Twenty-five university student novice runners were divided into two groups. After running a full marathon, one group wore MBT shoes (MBT group), and the control group (CON) wore ordinary shoes daily for 1 week following the race. We measured maximal isometric joint torque, muscle hardness (real time tissue elastography of the strain ratio) in the lower limb muscles before, immediately after, and 1, 3, and 8 days following the marathon. We calculated the magnitude of recovery by observing the difference in each value between the first measurement and the latter measurements. Results showed that isometric torques in knee flexion recovered at the first day after the race in the MBT group while it did not recover even at the eighth day in the CON group. Muscle hardness in the gastrocnemius and vastus lateralis showed enhanced recovery in the MBT group in comparison with the CON group. Also for muscle hardness in the tibialis anterior and biceps femoris, the timing of recovery was delayed in the CON group. In conclusion, wearing MBT shoes enhanced recovery in lower leg and thigh muscles from muscle damage induced by marathon running.

    DOI PubMed

    Scopus

    8
    Citation
    (Scopus)
  • Preliminary investigation of Real-time Feedback System from the Third-person Perspective Utilizing Augmented Reality(AR) on Skiing

    NAKAGAWA Kento, MIURA Satoshi, HIROOKA Kazumasa, UMESAWA Yumi, KANBA Hiroyuki, GOTO Yuta, FUJIMOTO Hiroshi, FUJIE Masakatsu, KANOSUE Kazuyuki

    Journal of Ski Science   15 ( 1 ) 77 - 82  2018  [Refereed]

     View Summary

    There are many situations that the difference between imagery(subjective) and actual(objective) movements occurs in skiing. In traditionally utilized feedback method with video, it is impossible to get real time visual feedback. In the present study, we developed the system for real-time visual feedback during skiing, and evaluated the availability of the system. The movie captured by a video-operator who followed a subject was projected in online through the smartglass that the subjects wore. Sixteen skiers and snowboarders with various skill levels tried this system.We interviewed subjects immediately after the trial.Their impression was that getting real-time visual feedback of their own motion utilizing the present system, which helped them modify their performance in middle and high level subjects. However, beginner subjects could not afford to use the feedback information. Since the present system had unavoidable time-delay of 186 ms, it was suggested that it is not suitable for learning short turn. Therefore, the present examination suggested that this real-time visual feedback system can be effective in learning long turn for middle and high level skier who have clear goal images of their performance.

    DOI CiNii

  • フルマラソン後の筋硬度と筋形状変化及び走破タイムとの関連性について

    米津 貴久, 中川 剣人, 稲見 崇孝, 深野 真子, 東原 綾子, 飯塚 哲司, 阿部 平, 成田 崇矢

    日本臨床スポーツ医学会誌   25 ( 4 ) S230 - S230  2017.10

  • Difference in Activity in the Supplementary Motor Area Depending on Limb Combination of Hand Foot Coordinated Movements

    Nakagawa K, Kawashima S, Mizuguchi N, and Kanosue K.

      10   499  2016.10  [Refereed]

     View Summary

    Periodic interlimb coordination shows lower performance when the ipsilateral hand and foot (e.g., right hand and right foot) are simultaneously moved than when the contralateral hand and foot (e.g., right hand and left foot) are simultaneously moved. The present study aimed to investigate how brain activity that is related to the dependence of hand-foot coordination on limb combination, using functional magnetic imaging. Twenty-one right-handed subjects performed periodic coordinated movements of the ipsilateral or contralateral hand and foot in the same or opposite direction in the sagittal plane. Kinematic data showed that performance was lower for the ipsilateral hand-foot coordination than for the contralateral one. A comparison of brain activity between the same and opposite directions showed that there was a greater activation of supplementary motor area for ipsilateral hand-foot coordination as compared to that seen during contralateral hand-foot coordination. We speculate that this might reflect a difference in the degree of inhibition of the neural circuit that disrupts opposite directional movements between ipsilateral and contralateral hand-foot coordinated movements.

    DOI

    Scopus

    9
    Citation
    (Scopus)
  • Muscle relaxation of the foot reduces corticospinal excitability of hand muscles and enhances intracortical inhibition

    Kouki Kato, Tetsuro Muraoka, Nobuaki Mizuguchi, Kento Nakagawa, Hiroki Nakata, Kazuyuki Kanosue

    Frontiers in Human Neuroscience   10 ( 2016 ) 218  2016.05  [Refereed]

     View Summary

    The object of this study was to clarify the effects of foot muscle relaxation on activity in the primary motor cortex (M1) of the hand area. Subjects were asked to volitionally relax the right foot from sustained contraction of either the dorsiflexor (tibialis anterior
    TA relaxation) or plantarflexor (soleus
    SOL relaxation) in response to an auditory stimulus. Single- and paired-pulse transcranial magnetic stimulation (TMS) was delivered to the hand area of the left M1 at different time intervals before and after the onset of TA or SOL relaxation. Motor evoked potentials (MEPs) were recorded from the right extensor carpi radialis (ECR) and flexor carpi radialis (FCR). MEP amplitudes of ECR and FCR caused by single-pulse TMS temporarily decreased after TA and SOL relaxation onset, respectively, d as compared with those of the resting control. Furthermore, short-interval intracortical inhibition (SICI) of ECR evaluated with paired-pulse TMS temporarily increased after TA relaxation onset. Our findings indicate that muscle relaxation of the dorsiflexor reduced corticospinal excitability of the ipsilateral hand muscles. This is most likely caused by an increase in intracortical inhibition.

    DOI

    Scopus

    11
    Citation
    (Scopus)
  • Interlimb coordination from a psychological perspective

    Tetsuro Muraoka, Kento Nakagawa, Kouki Kato, Weihuang Qi, Kazuyuki Kanosue

    The Journal of Physical Fitness and Sports Medicine   5 ( 5 ) 349 - 359  2016

    DOI

  • The relationship between maximal running speed and step frequency, step length, foot contact time, and aerial time during sprinting in elementary school children

    Nobuoka Sakie, Higuchi Takatoshi, Nakata Hiroki, Ogawa Tetsuya, Kato Kouki, Nakagawa Kento, Tsuchie Hiroyasu, Iso Shigeo, Kanosue Kazuyuki

    Taiikugaku kenkyu (Japan Journal of Physical Education, Health and Sport Sciences)   60 ( 2 ) 497 - 510  2015.12  [Refereed]

     View Summary

    &nbsp;&nbsp;The aim of this study was to clarify the relationship between maximal running speed, step frequency, step frequency index, step length, step length index, foot contact time, and aerial time during sprinting in elementary school children. The participants were 335 girls and 352 boys (age: 6 to 12 years) who ran a 50-m sprint race as part of their school fitness test in 2013. Their maximal running speed, step frequency, and step length were calculated from images captured by video cameras (60 frames/second) located at the sides of the lanes. Contact time and aerial time over the distance from 20 m to 30 m were calculated from images captured by high-speed video cameras (300 frames/second) located at the side of the 25-m mark for the lanes. Two-way ANOVA with the Games-Howell procedure was used to test differences among all grades. Two-way ANCOVA was used to test interaction and the main effect of gender and grade on maximal running speed. The Pearson product-moment correlation coefficient (r) and partial correlation coefficient (pr) were calculated to analyze the relationship between maximal running speed, step frequency, stride length, foot contact time, and aerial time. Step length (which was strongly correlated with maximal running speed) showed a strong partial correlation (controlled for age) with maximal running speed. Therefore, it is suggested that step length contributes to not only the increase in running speed with growth, but also individual differences in running speed among the children at the same age. There were slight tendencies for step frequency and foot contact time to increase with growth. However, these factors showed a significant partial correlation (controlled for age) with running speed. Therefore, it was suggested that these factors contribute to individual differences in running speed. The absence of a negative impact of a shorter foot contact time on stride length suggests that the running performance of school children could be improved by decreasing their foot contact time. In order to establish effective methods for augmenting the development of running ability in children, it will be necessary to consider foot contact time and aerial time in addition to step frequency and step length.<br>

    DOI CiNii

  • Corticospinal excitability modulation in resting digit muscles during cyclical movement of the digits of the ipsilateral limb

    Muraoka T, Sakamoto M, Mizuguchi N, Nakagawa K, Kanosue K

    Front Hum Neurosci   9   607  2015.11  [Refereed]

     View Summary

    We investigated how corticospinal excitability of the resting digit muscles was modulated by the digit movement in the ipsilateral limb. Subjects performed cyclical extension-flexion movements of either the right toes or fingers. To determine whether corticospinal excitability of the resting digit muscles was modulated on the basis of movement direction or action coupling between ipsilateral digits, the right forearm was maintained in either the pronated or supinated position. During the movement, the motor evoked potential (MEP) elicited by transcranial magnetic stimulation (TMS) was measured from either the resting right finger extensor and flexor, or toe extensor and flexor. For both finger and toe muscles, independent of forearm position. MEP amplitude of the flexor was greater during ipsilateral digit flexion as compared to extension, and MEP amplitude of the extensor was greater during ipsilateral digit extension as compared to flexion. An exception was that MEP amplitude of the toe flexor with the supinated forearm did not differ between during finger extension and flexion. These findings suggest that digit movement modulates corticospinal excitability of the digits of the ipsilateral limb such that the same action is preferred. Our results provide evidence for a better understanding of neural interactions between ipsilateral limbs, and may thus contribute to neurorehabilitation after a stroke or incomplete spinal cord injury.

    DOI

    Scopus

    4
    Citation
    (Scopus)
  • Potential explanation of limb combination performance differences for two-limb coordination tasks

    Kento Nakagawa, Tetsuro Muraoka, Kazuyuki Kanosue

    Physiological Reports   3 ( 2 ) e12301  2015  [Refereed]

     View Summary

    Rhythmic two-limb coordinated movements in the sagittal plane are variable and inaccurate when the movements are in the opposite direction as compared with those in the same direction (directional constraint). The magnitude of directional constraint depends on the particular limb combination. It is prominent in ipsilateral hand-foot coordination, but minimal in bimanual hand coordination. The reason for such differences remains unclear. In this study, we investigated the possible mechanisms underlying the production of the difference that depend on limb combination. Subjects performed two-limb rhythmic coordinated movements either in the same or in the opposite direction for three separate limb combinations (bilateral hands, contralateral hand and foot, and ipsilateral hand and foot). For each combination two different tasks were performed. In the first condition, subjects actively moved two limbs (active condition). Second, subjects actively moved one limb in coordination with a passively moved limb (passive condition). In the active condition, the directional constraint was dependent upon the limb combination, as reported in previous studies
    the directional constraint was quite prominent in ipsilateral combinations, intermediate in contralateral combinations, and minimal for bilateral combination. However, differences in the directional constraint did not depend on limb combination for any combination in the passive conditions which apparently utilized closed-loop control. In other word, the difference depending on limb combination disappeared when control strategies become uniformly closed-loop. Thus, we speculate that the control strategy utilized depends on limb combination in the active condition. Additionally, different mechanisms other than closed-loop control also would have influence depending on the particular limb combination. This may result in differences in performance depending upon the limb combination.

    DOI

    Scopus

    9
    Citation
    (Scopus)
  • Post-marathon wearing of Masai Barefoot Technology shoes facilitates recovery from race-induced fatigue: an evaluation utilizing a visual analog scale

    Kento Nakagawa, Takashi Obu, Kazuyuki Kanosue

    Open Access Journal of Sports Medicine     267 - 267  2014.12  [Refereed]

    DOI

  • Round-table talk: Coaching of Ski

    岡田 利修, 西村 斉, 樋口 貴俊, 中川 剣人, 加藤 孝基, 内田 雄介, 依田 珠江, 彼末 一之

    スポーツ科学研究   11   131 - 145  2014

    CiNii

  • 筋痙攣中のM波振幅の低下

    中川 剣人, 宮本直和, 村上雄治, 彼末一之

    東京体育学研究   4   11 - 16  2013.03  [Refereed]

  • Factors that determine directional constraint in ipsilateral hand–foot coordinated movements

    Kento Nakagawa, Tetsuro Muraoka, Kazuyuki Kanosue

    Physiological Reports   1 ( 5 ) e00108  2013  [Refereed]

     View Summary

    In performing simultaneous rhythmic movements of the ipsilateral hand and foot, there are differences in the level of stability between same directional (stable) and opposite directional (unstable) movements. This is the directional constraint. In this study, we investigated three factors (“interaction in efferent process,” “interaction of afferent signals,” and “error correction”) proposed to underlie for the directional constraint. We compared the performance of three tasks: (1) coordination of actively moved ipsilateral hand and foot, (2) active hand movement in coordination with passively moved foot, (3) active hand movement not coordinated with a passively moved foot. In each task, both same and opposite directional movements were executed. There was no difference between performance estimated with success rate for the first and second task. The directional constraint appeared in both tasks. Thus, the interaction in efferent processes, which was shown to be responsible for the directional constraint in bimanual coordination, was not involved with the directional constraint of ipsilateral hand–foot coordination. The directional constraint did not appear in the third task, which suggested that “interaction of afferent signals” also had no contribution. These results indicated that “error correction” must be the most critical of these factors for mediating the directional constraint in ipsilateral hand–foot coordinated movements.

    DOI

    Scopus

    7
    Citation
    (Scopus)
  • Influence of somatosensory input on corticospinal excitability during motor imagery

    Nobuaki Mizuguchi, Masanori Sakamoto, Tetsuro Muraoka, Noriyoshi Moriyama, Kento Nakagawa, Hiroki Nakata, Kazuyuki Kanosue

    Neuroscience Letters   514 ( 1 ) 127 - 130  2012.04  [Refereed]

    DOI

    Scopus

    17
    Citation
    (Scopus)
  • Influence of somatosensory input on corticospinal excitability during motor imagery

    Nobuaki Mizuguchi, Masanori Sakamoto, Tetsuro Muraoka, Noriyoshi Moriyama, Kento Nakagawa, Hiroki Nakata, Kazuyuki Kanosue

    Neuroscience Letters   514 ( 1 ) 127 - 130  2012.04  [Refereed]

    DOI

    Scopus

    17
    Citation
    (Scopus)
  • The Modulation of Corticospinal Excitability during Motor Imagery of Actions with Objects

    Nobuaki Mizuguchi, Masanori Sakamoto, Tetsuro Muraoka, Kento Nakagawa, Shoichi Kanazawa, Hiroki Nakata, Noriyoshi Moriyama, Kazuyuki Kanosue

    PLOS ONE   6 ( 10 ) e26006  2011.10  [Refereed]

     View Summary

    We investigated whether corticospinal excitability during motor imagery of actions (the power or the pincer grip) with objects was influenced by actually touching objects (tactile input) and by the congruency of posture with the imagined action (proprioceptive input). Corticospinal excitability was assessed by monitoring motor evoked potentials (MEPs) in the first dorsal interosseous following transcranial magnetic stimulation over the motor cortex. MEPs were recorded during imagery of the power grip of a larger-sized ball (7 cm) or the pincer grip of a smaller-sized ball (3 cm) with or without passively holding the larger-sized ball with the holding posture or the smaller-sized ball with the pinching posture. During imagery of the power grip, MEPs amplitude was increased only while the actual posture was the same as the imagined action (the holding posture). On the other hand, during imagery of the pincer grip while touching the ball, MEPs amplitude was enhanced in both postures. To examine the pure effect of touching (tactile input), we recorded MEPs during imagery of the power and pincer grip while touching various areas of an open palm with a flat foam pad. The MEPs amplitude was not affected by the palmer touching. These findings suggest that corticospinal excitability during imagery with an object is modulated by actually touching an object through the combination of tactile and proprioceptive inputs.

    DOI

    Scopus

    28
    Citation
    (Scopus)
  • 運動指令の違いが同側二肢協調動作の安定性に与える影響

    中川剣人, 田代哲朗, 小穴幸子, 村岡哲朗, 坂本将基, 彼末一之

    東京体育学研究   2   29 - 33  2010  [Refereed]

▼display all

Misc

  • Neural mechanisms of muscle cramp

    Kento Nakagawa, Naokazu Miyamoto, Kazuyuki Kanosue

    Sports Performance     79 - 90  2015.01

     View Summary

    Although muscle cramps are a common problem for many athletes, the underlyingmechanisms are still poorly understood. In this chapter, we review the proposed causesof muscle cramps. Dehydration and electrolyte disturbance are generally considered to be causes of muscle cramps, but this is unlikely. Alternatively, either neural activity in the spinal cord or in the peripheral could be the cause of cramps. Definitive evidence is scarce and controversy abounds.

    DOI

  • Remote effect of muscle relaxation

    Kato Kouki, Nakata Hiroki, Nakagawa Kento, Ogawa Tetsuya, Kanosue Kazuyuki

      11   90 - 90  2014

    CiNii

  • Elite dancers have greater auditory-motor synchronization in tapping task

    Kiyota N., Nakagawa K., Kato K., Suwa S., Kanosue K.

      11   95 - 95  2014

    CiNii

  • THE INFLUENCE OF ACTIVATION COUPLING OF CORRESPONDING MUSCLES OF FINGERS AND TOES ON THE STABILITY OF COORDINATED MOVEMENTS

    Tetsuro Muraoka, Masanori Sakamoto, Nobuaki Mizuguchi, Kento Nakagawa, Kazuyuki Kanosue

    JOURNAL OF PHYSIOLOGICAL SCIENCES   59   477 - 477  2009

    Research paper, summary (international conference)  

Research Projects

  • アスリートの競技力を規定する中枢神経系の解明:新たな神経機能向上法開発を見据えて

    日本学術振興会  科研費(基盤B)

    Project Year :

    2022.04
    -
    2027.03
     

    中川剣人

  • 力発揮の安定性に関わる中枢神経系機構の特定および機能改善の試み

    中富健康科学振興財団  第33回研究助成金

    Project Year :

    2021.04
    -
    2023.03
     

    中川剣人

  • アスリートにおける脳の可塑的変化に関わる要因および機能的役割の探索

    日本学術振興会  科研費(若手研究)

    Project Year :

    2020.04
    -
    2022.03
     

    中川剣人

  • 運動イメージと協調運動の脳機構に基づくスキー技術の学習支援システム構築

    日本学術振興会  科研費(基盤A)

    Project Year :

    2018.04
    -
    2022.03
     

    彼末一之

  • 簡便かつ非侵襲的な神経活動修飾による運動機能改善の試み

    日本学術振興会  科研費(若手研究B)

    Project Year :

    2017.04
    -
    2020.03
     

    中川剣人

  • 脊髄損傷患者に対する非侵襲的神経機能修飾による姿勢保持能力向上の試み

    日本学術振興会  海外特別研究員滞在費・研究活動費

    Project Year :

    2018.04
    -
    2019.03
     

    中川剣人

  • 筋腹刺激を用いた連合性ペア刺激による脊髄運動ニューロン修飾の試み

    明治安田厚生事業団  第35回明治安田厚生事業団健康科学研究助成

    Project Year :

    2018.10
    -
    2019.02
     

    中川剣人

  • 上・下肢協調運動の神経基盤の解明

    日本学術振興会  科研費(特別研究員奨励費)

    Project Year :

    2015.04
    -
    2018.03
     

    中川剣人

  • 不安定性を有するシューズの着用がマラソン後のリカバリーに有効か?

    公益財団法人ミズノスポーツ振興財団  スポーツ学等研究助成

    Project Year :

    2016.04
    -
    2017.03
     

    中川剣人

  • 磁気刺激による脊髄神経興奮性変調のための最適刺激部位の検討

    公益財団法人 磁気健康科学研究振興財団  第22回磁気健康科学研究助成

    Project Year :

    2016.04
    -
    2017.03
     

    中川剣人

  • 二肢間の機能的結合の機序の解明

    日本学術振興会  科研費(研究活動スタート支援)

    Project Year :

    2014.08
    -
    2015.03
     

    中川剣人

  • 複数肢協調運動のメカニズムの解明

    日本学術振興会  科研費(特別研究員奨励費)

    Project Year :

    2012.04
    -
    2014.03
     

    中川剣人

▼display all

Specific Research

  • 脳内代謝物質測定による一次運動野の可塑性の検討

    2021  

     View Summary

    競技トレーニングによる中枢神経系の可塑的変化のメカニズムを検討するため、今年度は、脳の可塑的変化の新たな指標として脳内代謝物質に着目した。一次運動野の手領域、足領域を関心領域として設定し、競技種目による違いが一次運動野の脳内代謝物質の組成にどのように影響するかを検討することを目的とした。最初に予備実験を重ねてノイズの混じらないデータの撮り方を習得した。本実験として、約100名の種々の競技アスリート、または運動習慣のない者を対象に、3テスラMR装置を用いて脳内代謝物質の測定が完了した。現在データ解析を進めており、最終的な成果は国際神経科学雑誌に発表する予定である。

  • 過酷な運動による中枢神経系の可塑的変化

    2020  

     View Summary

    巧緻性を伴う運動スキルトレーニングが中枢神経系の可塑的変化を誘導することが知られているが、巧緻性を伴わない一過性の過酷な運動を行うことによってどのように中枢神経系が可塑的に変化するかは不明である。本研究では、被験者に長時間のランニングを課し、その前後での脳構造変化を検討した。脳構造測定には、MRIを用いて、脳のT1強調画像を取得した。解析では、Voxel-based morphometry (VBM)による局所的な灰白質容量変化を検討した。その結果、運動前に比べて運動後に灰白質量が減少した領域はなかったが、左半球中前頭回のボリュームが増加する傾向にあった(p &lt; 0.001, uncorrected)。今後、さらに頑健な統計処理を実施するため、追加実験を行っていく。

  • アスリートの可塑性における競技特性の検討

    2019  

     View Summary

    アスリートにおける中枢神経系の可塑的変化を検討するため、二種類の実験を行った。一つは、脊髄反射の可塑的変化を調べるため、脛骨神経への電気刺激によってヒラメ筋からH反射を誘発し、M波最大振幅値に対するH反射最大振幅値を脊髄反射の興奮性の指標として評価した。また、姿勢によるH反射の変動にアスリート特異性が見られるか検討するため、伏臥位と立位の二条件でH反射のリクルートメントカーブを計測した。また、MRIを用いて、アスリートにおける脳の構造、安静時機能ネットワークを計測する実験を行った。今後も研究を継続し、被験者数を増やしたうえで、アスリートにおける特異的な中枢神経系の可塑的変化を明らかにする予定である。

 

Syllabus

▼display all