Engardt M
Department of Orthopaedics, Karolinska Institute, Stockholm.
Scand J Rehabil Med Suppl. 1994;31:1-57.
The purpose was to study vertical ground reaction force feedback and dynamic knee extensor training used to enhance stroke patients' symmetrical body weight distribution while rising and sitting down. Sixteen healthy subjects and 51 stroke patients participated in the studies. Two vertical strain gauge force transducers attached to two force-measuring platforms were used to measure body weight distribution over the lower limbs. An auditory feedback device, specially developed for training body weight distribution on the paretic leg, employed two electronic balances sensing vertical forces from each foot, separately. Torque of maximal voluntary eccentric and concentric knee extensor and flexor actions at 30, 60, 120, 180 and 240 deg/s was recorded with an isokinetic dynamometer together with surface electrodes from the quadriceps and hamstring muscles. When instructed to rise with even body weight on each lower limb, the stroke patients loaded the paretic leg more than when rising habitually, indicating that stroke patients have a latent motor capacity. Stroke patients' own estimations on visual analogue scales of body weight distributed on the paretic leg correlated with measured loading of the paretic leg in rising. After six weeks of training with auditory feedback of vertical ground reaction forces in the acute phase after stroke, the patients improved their loading of the paretic leg compared to a control group. The patients distributed body weight over the lower limbs nearly symmetrically while rising and while sitting down. The peak torque was not greater, however, than in the control group, rising with an asymmetrical body weight distribution. This implies that the patients after feedback training were better at using the knee extensor torque of the paretic leg to attain symmetrical body weight distribution over the lower extremities. Changes in improvement of physical performance and sitting to standing were greater than in the control group. No differences between groups were seen in performance of activities of daily living. Body weight distribution over the limbs in rising and in sitting down was re-tested on average 33 months after end of training. The symmetrical weight distribution after feedback training was not maintained over time. Knee extensor strength improved after six weeks of eccentric and concentric training, starting on average 27 months after stroke. The increase in strength was related to enhanced activation of agonist EMG activity. Eccentric training seems to be superior to concentric training with reference to a) improved body weight distribution over the lower limbs in rising, to b) increased knee extension torque and to c) increased agonist EMG activity without a concomitant, augmented EMG activity of the antagonistic knee flexor muscles. It was concluded that stroke patients have a latent motor capacity, that six weeks auditory feedback training promotes symmetrical body weight distribution which, however, is not consistent over time and that isokinetic eccentric training is superior to concentric training with reference to weight distribution in rising, knee extension torque and EMG activity.
目的是研究垂直地面反作用力反馈和动态伸膝训练，以增强中风患者起身和坐下时的对称体重分布。16名健康受试者和51名中风患者参与了研究。两个附着在测力平台上的垂直应变片式力传感器用于测量下肢的体重分布。一种专门为训练患侧腿体重分布而开发的听觉反馈装置，采用两个电子天平分别感应每只脚的垂直力。使用等速测力计和股四头肌及绳肌的表面电极记录在30、60、120、180和240度/秒时最大自主离心和向心伸膝及屈膝动作的扭矩。当被指示在每个下肢均匀承重起身时，中风患者在患侧腿上的负重比习惯性起身时更多，这表明中风患者具有潜在的运动能力。中风患者在视觉模拟量表上对患侧腿体重分布的自我估计与起身时患侧腿的实际负重相关。在中风急性期进行六周的垂直地面反作用力听觉反馈训练后，与对照组相比，患者患侧腿的负重有所改善。患者在起身和坐下时下肢的体重分布几乎对称。然而，峰值扭矩并不比对照组更大，对照组是以不对称的体重分布起身的。这意味着反馈训练后的患者在利用患侧腿的伸膝扭矩以实现下肢对称体重分布方面表现更好。身体机能改善和从坐到站的变化比对照组更大。在日常生活活动表现方面，两组之间没有差异。在训练结束后平均33个月对起身和坐下时肢体的体重分布进行了重新测试。反馈训练后的对称体重分布并未随时间维持。在中风后平均27个月开始进行六周的离心和向心训练后，伸膝力量有所改善。力量的增加与主动肌肌电图活动的增强有关。就以下方面而言，离心训练似乎优于向心训练：a）起身时下肢体重分布改善；b）伸膝扭矩增加；c）主动肌肌电图活动增加，而拮抗肌屈膝肌的肌电图活动没有相应增强。研究得出结论，中风患者具有潜在的运动能力，六周的听觉反馈训练可促进对称体重分布，但这种分布随时间并不一致，并且就起身时的体重分布、伸膝扭矩和肌电图活动而言，等速离心训练优于向心训练。
