Tibial rotation during foot pronation has been proposed as a key factor in running related injuries. Precise analysis of knee motion during running, including the analysis of motion in the coronal plane, is difficult, and the effect of the wearing shoes on tibial rotation during running is unknown. Therefore, we aimed to determine the effect of wearing shoes in reducing tibial rotation during running. Fifteen healthy subjects (nine males, six females) participated in this study
25 markers were secured on the left lower extremity of each subject. Three-dimensional kinematic data were collected using the MAC3D System (Motion Analysis Co.). The data were processed using the point cluster technique (Andriacchi et al. 1998, J Biomech Eng 120, 743). The subjects were required to run (a) barefoot and (b) while wearing athletic running shoes (Adidas Response Cushion). Tibial motion with respect to the femur was assessed in the stance phase. The internal/external rotation, adduction/abduction and flexion of knee joint were analyzed for a period of 100 ms after foot strike. In both the conditions, all subjects experienced internal tibial rotation after foot strike. During the 100-ms period after foot strike, the shoes reduced the amount of tibial rotation during running (barefoot 16.0 ± 4.1°, shod 13.7 ± 5.3°). The angular change of the knee flexion was increased with running shoe (barefoot 20.8 ± 4.9°, shod 26.5 ± 4.2°). These findings suggest that tibial rotation can be reduced by wearing athletic running shoes. © 2009 Taylor &amp
Francis Group, LLC.

A decrease of deep knee flexion torque after anterior cruciate ligament (ACL) reconstruction, using a semitendinosus (and gracilis) tendon, has been reported. However, the cause of this weakness remains controversial. Architectural and functional differences in the knee flexor muscles influence this weakness. the fiber length of the semitendinosus, gracilis, semimembranosus, and biceps femoris were directly measured in six human cadavers. The flexion torque and EMG of the hamstrings were measured in both limbs of 16 patients (23 +/- 5 years) after ACL reconstruction (12-43 months post-operation), using ipsilateral semitendinosus tendon. Magnetic resonance imagings were taken, over both the thighs of those patients, to measure muscle volume and to confirm a state of semitendinosus tendon regeneration. The position of the musculotendinous junction of the semitendinosus was also analyzed. The fiber length of the semitendinosus and gracilis were three to four times longer than that of the semimembranosus and biceps femoris. The difference of flexion torque between the normal and ACL reconstructed limbs significantly increased as the knee flexion angle increased. The EMG value for the semimembranosus and biceps femoris of both limbs as well as the semitendinosus of the ACL reconstructed limbs, significantly reduced as the knee flexion angle was increased. The volume of the semitendinosus in the reconstructed limb was significantly smaller than in normal limbs. The regeneration of the semitendinosus tendon was confirmed in all subjects, and the musculotendinous junction position of the reconstructed limb in almost all subjects was found in further image from the knee joint space than that for the normal limb. The decrease of deep knee flexion torque, after ACL reconstruction, could be due to the atrophy and shortening of the semitendinosus after its tendon has been harvested, as well as the lack of compensation from the semimembranosus and biceps femoris, due to the architectural differences between the semitendinosus and the semimembranosus and biceps femoris.

In this study, the effect of biological maturity in developments of central information processing (CIP) evaluated from choice reaction time (CRT) was investigated from cross-sectional and longitudinal studies. The subjects were Japanese adolescent soccer players. Biological maturity was evaluated according to skeletal age. CRT was measured using the Talent-Diagnose-System. In the cross-sectional study, skeletal age correlated with CRT (r = -0.52, p &lt
0.01), and there were some differences in developmental aspects of CRT between chronological age and skeletal age. In the longitudinal study, CRT improved significantly from 10 to 11 years of chronological age. During this period, development of skeletal age exceeded chronological maturation. Moreover, the annual improvement of CRT correlated with that of skeletal age (r=-0.45, p &lt
0.01). Our results suggest that while we have to consider the effect of external input, such as experience and training, development of CIP was influenced by development of biological maturity in Japanese adolescent soccer players.

KONISHI, Y. Y. SUZUKI, N. HIROSE, and T. FUKUBAYASHI. Effects of Lidocaine into Knee on QF Strength and EMG in Patients with ACL Lesion. Med. Sci. Sports Exerc., Vol. 35, No. 11, pp. 1805-1808, 2003. Purpose: In our previous study, we found that injection of lidocaine into intact knees reduced the maximal voluntary contraction (MVC) and integrated electromyogram (I-EMG) of the quadriceps femoris (QF). This study was designed to investigate changes in the MVC and I-EMG of the QF in response to lidocaine, in patients with anterior cruciate, ligament (ACL) lesion, to evaluate alpha-motoneuron activity innervating the QF. Methods: The MVC of knee extension and I-EMG of the vastus medialis (VM), vastus lateralis (VL), and rectus femoris (RF) muscles were measured in eight patients with ruptured ACL, before and after lidocaine injection into the knee. Results: There were no significant differences between preinjection and postinjection values of MVC (preinjection: 167 +/- 49 N(.)m; postinjection: 164 +/- 55 N(.)m) and I-EMG (preinjection: VL: 0.11 +/- 0.06, VM: 0.13 +/- 0.10, RF: 0.09 +/- 0.04) (postinjection: VL: 0.12 +/- 0.07, VM: 0.13 +/- 0.10, RF: 0.09 +/- 0.05). Conclusion: Our results indicated that hindrance of afferent feedback from the knee in patients with ACL rupture did not significantly change alpha-motoneuron activity. Lidocaine injection into the knee joint of the subjects in this study only attenuated afferent feedback from mechanoreceptors in the knee joint cavity, but not in the ACL. as afferent feedback from ACL was already lost due to ACL rupture. This indicated that attenuation of afferent feedback from mechanoreceptors in the knee joint cavity other than the ACL did not significantly decrease the activity of alpha-motoneurons innervating the QF during MVC exertion. Therefore, our findings provide evidence that afferent feedback from the ACL has a major influence on the MVC exertion of the QF.

Introduction: Acupuncture is used to modulate the physical well-being of athletes in Asian countries. However, there is little information on the immediate effects of acupuncture treatment on physiological or psychological responses to exercise. Purpose: The purpose of this study was to examine the effect of acupuncture treatment on the physical well-being of elite female soccer players during a competition period. Methods: Subjects were divided into two groups: those who received acupuncture treatment (18.1 +/- 2.3 yr [+/-SD], N = 9) and a control group (17.7 +/- 2.8 yr, N = 12). In the treatment group, acupuncture stimulus was applied at LI 4 (Goukoku), ST 36 (Ashi-sanri) for 20 min, and ST 6 (Kyosya), LU 6 (Ko-sai) points for 15 min 4 h after the game every night during the competition period. The measured parameters included salivary secretory immunoglobulin A (SIgA) level, cortisol level in saliva, subjective rating of physical well-being, and profile of mood states (POMS). Results: The following were the main results: 1) Exercise-induced decrease of salivary SIgA and increase of salivary cortisol were inhibited by acupuncture. 2) Acupuncture improved subjective rating of muscle tension and fatigue. 3) The POMS score was modulated by acupuncture. Conclusion: These results support the effectiveness of acupuncture for physical and mental well-being of athletes.

Purpose: The aim of our study was to test for any neurophysiological abnormality in the gamma loop in the quadriceps femoris muscle on the uninjured side of patients with unilateral rupture of the anterior cruciate ligament (ACL). Methods: Maximal voluntary contraction of knee extension and integrated electromyography (I-EMG) of the vastus medialis, vastus lateralis, and rectus femoris were measured in the uninjured limb of 13 patients with unilateral ACL rupture and 10 normal subjects, before and after 20-min vibration stimulation applied to the infrapatellar tendon. Results: The mean percentage changes of maximal voluntary contraction and I-EMG in quadriceps femoris of the uninjured side of patients with ACL rupture were significantly different from those of the control group. Maximal voluntary contraction and I-EMG after prolonged vibration stimulation did not decrease as much as those of the control group even though the same protocol of vibration stimulation was applied. Conclusion: The abnormal response to prolonged vibration stimulation could represent abnormal gamma loop in the quadriceps femoris muscle of the uninjured side in patients with ACL rupture since the normal response of maximal voluntary contraction and I-EMG to prolonged vibration stimulation could not be evoked without normal function of the gamma loop.

This study evaluated intramuscular movement of hamstrings muscle after reconstruction of the ACL with a hamstrings tendon graft. The movement of the muscles during knee flexion was measured using a novel MRI technique called the "tagging snapshot" technique, which labels multiple tagging bands within the musculature. Eleven patients who underwent ACL reconstruction using autogenous semitendinosus and gracilis tendons were studied. The difference in the maximum active knee flexion angle between the ACL-reconstructed and the intact knee was calculated as knee flexion lag. Knee flexion strength was measured in 8 of the 11 patients. The semitendinosus muscle of the ACL-reconstructed knee exhibited three different morphological patterns
group I, similar shape to the intact knee with distal tendonlike structures
group II, smaller proximally than the intact knee with distal tendonlike structures
and group III, considerably smaller proximally than the intact knee without distal tendonlike structures. Each group was associated with a different knee flexion lag and different knee flexion strength. Our results indicated that the effect of hamstrings tendon harvest on knee function is not uniform.

The purpose of this study was to examine whether mechanical stretch alters the expression of myogenic regulatory factors in cultured myogenic satellite cells. C2Cl2 myogenic satellite cells were plated on collagenized silastic membrane and cultured in growth medium and stretched with 20% elongation for 24 h. The expressions of myogenic regulatory factors including MyoD, myogenin, myocyte nuclear factor (MNF)-alpha and -beta were determined by semiquantitive reverse transcriptional-polymerase chain reaction (RT-PCR) analysis, The expressions of MyoD and MNF-alpha were decreased in stretched C2Cl2 as compared to control condition. The expressions of myogenin and MNF-beta were not detected. These results demonstrate that mechanical stretch inhibits differentiation of C2Cl2 myogenic satellite cells to myotube in the cultured condition. (C) 2001 Elsevier Science B.V. All rights reserved.

The Gore-Tex anterior cruciate ligament has been implanted in 123 patients at our institutions between 1984 and 1993. The Gore-Tex ligaments were totally ruptured in 26 cases. In the remaining 97 cases, 80 were followed up 5-11 years after operation. Graft loosening occurred in half of the cases, and osteoarthritic change was developed in 62% of the cases. Moreover, tibial and tunnel osteolysis was observed in most of the cases. Judging from these follow-up results, the Gore-Tex ligament should not be used for anterior cruciate ligament reconstruction.

【目的】前十字靭帯(以下ACL)の損傷はスポーツ外傷では最も注目されている疾患の一つである．スポーツ活動への復帰を希望する者に対してはACL再建術とその後のアスレチックリハビリテーションが不可欠である．しかし ACL再建術後の大腿四頭筋の回復過程を生理学的な側面と形態学的な側面の両方から詳細に研究したものは見当たらない．そこで本研究はACL再建術後の大腿四頭筋の形態および筋活動がいかに変化し，また回復するかの詳細を検討することを目的として，ACL再建患者の大腿四頭筋の筋体積および固有筋力の変化，膝伸展トルク，大腿直筋，外側広筋，内側広筋の筋放電量の縦断的な計測評価を行いその予防対策を立てることを目的とした。【方法】ACLの再建を行った患者のうち，リハビリテーション経過を観察できた18名(男性8名，女性10名)を対象とした．MRIを用いて術後3，4，6，9，12ヶ月経過時に大腿部の筋体積を計測すると共にに、等尺性膝伸展筋力をBIODEX SYSTEM 3を用い90°,75°,45°で計測した．また筋電計（バイオモニターME6000）を用いて大腿直筋，外側広筋，内側広筋の表面筋電図を記録した．【結果】ACL再建術後の大腿四頭筋では平均して10%程度の筋萎縮が見られた。萎縮は内側広筋を中心として起こり，他の3筋は萎縮が多少軽微であった。筋力は筋断面より術後早期にその落ち込みが大きかったが、術後半年以上ではその程度はほぼ筋萎縮の程度と比例した。筋放電量では各角度の比較では筋トルクと同様に90°の対健側比が高く，角度が浅くなっていくほど筋放電量が低下する傾向がみられた．経時的変化では少なくとも術後9ヵ月までは内側広筋の筋放電量の低下が残存することが認められた．筋断面積当たりの筋出力は固有筋力と呼ばれているが、この固有筋力はいずれの角度でも術後6ヵ月までは有意な差が認められたが，それ以降は有意な差が認められなかった．これらのことから術後の大腿四頭筋の筋力低下は筋萎縮による筋体積減少に加え，神経筋反応を介して高次機能からの神経的抑制や脊髄レベルでの関与が考えられた． ACL再建術後の早期の完全な復帰を行なうためには，単に術後のリハビリテーションメニューを加速するだけでなく，神経筋の反応を十分考慮し，術後早期より内側広筋に十分な刺激を加えるようなメニューや，早期の手術部の炎症の鎮静化や，メカノレセプターの再生を促すメニューの確立が必要と思われた．

前十字靱帯再建術施行後の半腱様筋腱の再生度合いに関する臨床的研究は本年度よりスポーツ科学部に設置される1.5T超伝導MRIを使用し、術後２週、４週、８週、１２週、２４週で行った。再生半腱様筋腱は最初血腫と同様のMRI画像を呈するが徐々にその輝度が筋，腱組織に類似してくることが観察された．今回の術後患者６名を用いた検討では術後１ヶ月～２ヶ月でT2画像上筋組織と同等の輝度を有し，術後３ヶ月～６ヶ月で腱組織と同等の輝度を有した．なお６ヶ月以後はMRI上では輝度の変化は見られなかった．各時期でのT2値の測定を試みたが今回信頼性の高い値を得ることができなかった．なお術後３年以上経過例２例での肉眼，および組織所見では再建靱帯はほぼ正常腱組織をていし，筋腱移行部にも瘢痕形成は見られず肉眼および組織所見上では完全な腱再生がなされていた．リハビリテーションメニューの差異による再生の差異も検討したが今回は症例が少なく明らかな差異を見つけられなかった．動物実験は山羊２４頭を使用し膝の前十字靱帯再建術を施行したが，その時使用した足指の伸筋腱の再生度合いを術後６週，３ヶ月，１年で検討した．肉眼的には術後６週では摘出した腱の後に血塊の一部と疎生結合織がみられた．組織学的には血管にとんだ組織で肉芽組織と線維芽細胞が多数見られた．まだ線維の配列はなされていなかった．術後３ヶ月では術後６週と同程度にとどまり瘢痕化してくる例と，徐々に線維性配列が見られてくる例が観察された．術後１年経過例では腱摘出部がそのまま瘢痕組織に置き換わり周囲と癒着してしまう例と，癒着しながらも内部に線維性配列が出来て，腱再生の機序が観察される例の２種類に大別された．しかし人に見られる様な完全な再生は観察されなかった．なお現在生化学的分析は進行中でありその結果ついては別途後日報告したい．

① 死体解剖による半膜様筋，大腿二頭筋，半腱様筋、薄筋の筋長，筋線維長，羽状角の計測：６体の計測結果では四筋とも筋長は25 cm程度で同一である．半膜様筋，大腿二頭筋は23度の羽状角を持つ半羽状筋であり，筋線維長は6 cm程度と短い．一方半腱様筋，薄筋は紡錘筋であり，羽状角はなく筋線維長は平均24 cmと長い．② 筋力の測定：術後１年以上を経て術前のスポーツに復帰した前十字靱帯再建選手に対し筋力計測器（Biodex3）を用いて，腹臥位（股関節伸展位）の肢位で膝関節30度，45度，60度，90度，105度での等尺性屈曲筋力を測定した．30度，45度では健患側差はないが，90度，105度で患側の筋力が30%程度低下が明らかになった．③ 筋体積の測定：MRIを用いて膝関節裂隙から坐骨結節までの大腿筋のT1強調の連続水平横断画像をスライス厚10 mm，スライス間隔2.5 mmで作成．NIHイメージより半膜様筋，大腿二頭筋，半腱様筋の体積を計算した．腱が採取された患側の半腱様筋では健側の70 %程度に筋体積は萎縮しているが，半膜様筋，大腿二頭筋は健患側で差異が無く代償性肥大が見られなかった．④ 積分筋電値（I-EMG）の測定：ホルター型筋電計（ME-3000P4 MEGA社）を用いて半膜様筋，大腿二頭筋，半腱様筋の表面筋電値を筋力測定と同一肢位で最大筋力の50% 時に測定した．半膜様筋，大腿二頭筋でのI-EMGは30度，45度膝屈曲位に比較して90度，105度屈曲位では健患側とも明らかにその値が低下した．半腱様筋では健側90度屈曲位でもI-EMG値の低下は見られない．一方患側では半腱様筋はその特性は失われ，半膜様筋に類似した減少パターンを示した．⑤双極性ワイア電極（TN201-231, ユニークメデイカル）を併用し健常人10名で④と同じ実験を試行した．結果として④と同様の結果が得られ表面電極による信頼性が確保された．実験①～⑤により半腱様筋，薄筋は構造また機能の両面から半膜様筋，大腿二頭筋と明らかに異なること．この腱をACL再建のため採取することにより半腱様筋は術後機能不全に陥るが，これを半膜様筋，大腿二頭筋では補い得ず，結果的に深屈曲位における筋力低下が生じると推察される．