Schmitz Randy J, Kim Hyunsoo, Shultz Sandra J
Department of Kinesiology, University of North Carolina at Greensboro;
J Athl Train. 2015 Jan;50(1):23-9. doi: 10.4085/1062-6050-49.3.79. Epub 2014 Nov 6.
Fatigue is suggested to be a risk factor for anterior cruciate ligament injury. Fatiguing exercise can affect neuromuscular control and laxity of the knee joint, which may render the knee less able to resist externally applied loads. Few authors have examined the effects of fatiguing exercise on knee biomechanics during the in vivo transition of the knee from non-weight bearing to weight bearing, the time when anterior cruciate ligament injury likely occurs.
To investigate the effect of fatiguing exercise on tibiofemoral joint biomechanics during the transition from non-weight bearing to early weight bearing.
Cross-sectional study.
Research laboratory.
Ten participants (5 men and 5 women; age = 25.3 ± 4.0 years) with no previous history of knee-ligament injury to the dominant leg.
INTERVENTION(S): Participants were tested before (preexercise) and after (postexercise) a protocol consisting of repeated leg presses (15 repetitions from 10°-40° of knee flexion, 10 seconds' rest) against a 60% body-weight load until they were unable to complete a full bout of repetitions.
MAIN OUTCOME MEASURE(S): Electromagnetic sensors measured anterior tibial translation and knee-flexion excursion during the application of a 40% body-weight axial compressive load to the bottom of the foot, simulating weight acceptance. A force transducer recorded axial compressive force.
The axial compressive force (351.8 ± 44.3 N versus 374.0 ± 47.9 N; P = .018), knee-flexion excursion (8.0° ± 4.0° versus 10.2° ± 3.7°; P = .046), and anterior tibial translation (6.7 ± 1.7 mm versus 8.2 ± 1.9 mm; P < .001) increased from preexercise to postexercise. No significant correlations were noted.
Neuromuscular fatigue may impair initial knee-joint stabilization during weight acceptance, leading to greater accessory motion at the knee and the potential for greater anterior cruciate ligament loading.
疲劳被认为是前交叉韧带损伤的一个风险因素。疲劳运动会影响神经肌肉控制和膝关节的松弛度，这可能使膝关节对外加负荷的抵抗能力降低。很少有作者研究疲劳运动在膝关节从非负重到负重的体内转变过程中对膝关节生物力学的影响，而前交叉韧带损伤很可能发生在这个时期。
研究疲劳运动在从非负重到早期负重转变过程中对胫股关节生物力学的影响。
横断面研究。
研究实验室。
10名参与者（5名男性和5名女性；年龄=25.3±4.0岁），优势腿无前膝关节韧带损伤史。
参与者在一项方案（包括对60%体重负荷进行重复腿部推举，膝关节从10°屈曲到40°，重复15次，休息10秒）之前（运动前）和之后（运动后）接受测试，直到他们无法完成一轮完整的重复动作。
电磁传感器在对足底施加40%体重的轴向压缩负荷以模拟承重时，测量胫骨前移和膝关节屈曲偏移。一个力传感器记录轴向压缩力。
从运动前到运动后，轴向压缩力（351.8±44.3牛与374.0±47.9牛；P=0.018）、膝关节屈曲偏移（8.0°±4.0°与10.2°±3.7°；P=0.046）和胫骨前移（6.7±1.7毫米与8.2±1.9毫米；P<0.001）均增加。未发现显著相关性。
神经肌肉疲劳可能会损害承重时膝关节的初始稳定性，导致膝关节出现更大的附属运动以及前交叉韧带承受更大负荷的可能性。
