Plyometric exercises: Subsequent changes of weightbearing symmetry, muscle strength and walking performance in children with unilateral cerebral palsy

Objective: To evaluate the subsequent effects of plyometric training on weight-bearing symmetry, muscle strength, and gait performance in children with unilateral cerebral palsy. Methods: Thirty-nine children with spastic hemiplegia (age 8-12 years) were randomly divided into either the PLYO group (n=19, received a 30-minute plyometric exercise program plus the traditional physical rehabilitation, twice/week for eight consecutive weeks) or Non-PLYO group (n=20, received the traditional physical rehabilitation only). The weight-bearing symmetry index (WB-SI), maximum isometric muscle strength (MIMS) of quadriceps and hamstring muscles, and spatial-temporal gait parameters were assessed pre and post-intervention. Results: From pre- to post-intervention, changes of WB-SI among PLYO and Non-PLYO groups did not differ significantly (P=.81; hindfoot and P=.23; forefoot). MIMS of quadriceps and hamstring muscles at 90o knee flexion (P=.008 and.013 respectively) increased significantly in PLYO compared to Non-PLYO group. Walking speed (P=.033), stride length (P=.002), and step time (P<.001) improved markedly in PLYO group more than in Non-PLYO group. The proportion of single leg support (P=.14) among PLYO and Non-PLYO groups did not differ significantly. Conclusion: Addition of plyometric exercises to the physical rehabilitation programs of children with unilateral CP could achieve greater improvement in muscles strength and walking performance, but not in WB-SI.