Knee dystocia in children with cerebral palsy
The most prominent clinical manifestation of knee anteversion in cerebral palsy is increased muscle tone, low muscle strength, and excessive knee anteversion. Therefore, improving the muscle strength of quadriceps and N cord muscles, reducing their muscle tone, relieving gastrocnemius spasm, and inhibiting knee anteversion are the keys to promote the improvement of motor function in children with cerebral palsy. There are many treatment methods for pediatric cerebral palsy, and massage and exercise therapy are adopted for knee anteversion, but the principle of comprehensive rehabilitation is the main one.
The following motor training is commonly used [16].
① Squatting training, knee flexion about 90° when squatting, knee joint should be 140° to 160° when standing to avoid knee hyperextension. ② prone position calf flexion and extension training to improve N cord muscle strength and increase knee stability.
③ single and double leg kneeling training, which helps to improve the control of the knee joint.
④Crawling training with knee flexion and flexion position is beneficial to correct the antalgia, while increasing the control ability of the knee joint and coordinating its motor function. Knee flexion and extension, foot dorsiflexion training, to improve the strength of the extensor muscles and coordinate the tension of the antagonist muscles.
⑤ Calf triceps retraction and muscle strength training, let the child’s forefoot on a small step, heel on the ground, mainly to train the child to put down the heel (pulling gastrocnemius) and lift the heel (improve gastrocnemius muscle strength), for the most needed strength training during the swing period.
(6) Bridge training, to enhance the strength of the extensor muscles, promote hip extension, and correct trunk forward flexion.
(7) Up and down step training, which has a greater role in correcting knee dystocia and coordinating gait, but should be noted to keep the knee joint slightly flexed.
(8) Weight-bearing standing training, which can be combined with straps or braces to fix the child’s lower limbs to avoid knee hyperextension, which helps to improve the stability of the knee joint and increase proprioception.
Different training can also be done in different positions according to the different motor abilities of the child, and the specific procedures are as follows [17].
① Training hip flexion and knee flexion in the supine position. Emphasize selective flexion and extension of the hip and knee joints, and maintain full ankle dorsiflexion. The hip joint is not abducted and externally rotated, and knee extensor spasm is inhibited.
② Training knee flexion in the supine position with the hip extended. Emphasize knee flexion, and full ankle dorsiflexion, and control ankle plantarflexion.
(③Train active knee flexion in the prone position. Emphasize the non-flexion of the affected hip joint.
④Knee four-point kneeling position, knee two-point kneeling position: knee four-point kneeling position emphasizes hip inversion, knees one shoulder width apart, hip flexion, knee flexion, knee weight bearing, and ankle dorsiflexion. The upper limb maintains forward flexion of the shoulder joint, extension of the elbow joint, rotation of the forearm and full dorsiflexion of the wrist joint. The knee two-point kneeling position emphasizes one shoulder width apart, hip extension and knee flexion, and knee weight bearing.
⑤ In sitting position, train to actively cross the affected leg over the healthy leg, emphasizing hip flexion and knee flexion, and ankle dorsiflexion. The affected leg should not be pulled by the healthy hand.
⑥In the standing position, train the affected leg to step with the knee flexed without lifting the hip and with the knee joint relaxed. Emphasize knee flexion without lifting the pelvis.
(7) During the standing period, train the affected leg to extend the hip and bend the knee, and stand with the healthy leg. Emphasize hip inversion, hip extension and knee flexion.
(8) During the standing period, train the patient to stand with the legs crossed. Emphasize that the affected leg is in front and slightly flexed against the healthy knee.
Exercise therapy should pay attention to the training of muscle strength and posture correction. Posture correction, such as pointed foot and trunk flexion, should not be performed until the posture is corrected and the extensor spasm is relieved, and orthotics should be worn to ensure knee stability if necessary. For knee anteversion below 10°, it is beneficial to stabilize the knee joint and does not require correction. Treatment should not look at each muscle or joint activity alone, but should be trained for function.