右立脚後期に右下肢の蹴り出しが不十分であった右脛骨開放骨折患者の一症例

―足関節背屈位での下腿三頭筋の筋活動に着目して―

抄録

Recently, we encountered a case of open fracture of the right tibia with insufficient kick-off of the right lower extremity during the late stance phase. Physical therapy was administered for this case. In analysis of the gait pattern, this patient showed no anterior inclination of the right leg throughout the stance phase but exhibited hyperextension of the right knee joint. During the late stance phase, the right ankle joint remained in plantar flexion and kick-off was insufficient. To treat this condition, we initially provided range-of-motion (ROM) training to expand the range of dorsiflexion of the right ankle joint. This training alleviated the restricted ROM of the right ankle dorsiflexion; however, the right-knee hyperextension during the middle stance phase persisted and kick-off during the late stance phase did not improve. Electromyographic evaluation revealed insufficient activity of the triceps surae muscle of the right leg during the middle stance phase. We began muscular reinforcement training for the triceps surae muscle to improve the range of ankle joint dorsiflexion. Following the treatment, the electromyographic pattern became closer to the pattern observed in normal individuals. During the middle stance phase of the right lower limb, improvement was observed in the activity of the right triceps surae muscle in relation to the range of ankle joint dorsiflexion, enabling the patient to keep the leg inclined forward. As a result, right ankle dorsiflexion appeared during the middle stance phase, leading to the disappearance of knee-joint hyperextension. At the same time, the patient regained the capability of right ankle plantar flexion from the position of dorsiflexion and also showed improved kick-off during the late stance phase. Our experience with this case indicates the importance of considering the leg position in which muscular activity is poor.