The effects of closed and open kinetic chain exercises on lower limb muscle activity and balance in stroke survivors

OBJECTIVE: The major contributors to physical disability after stroke are the negative impairments related to loss of functional ability and muscle strength. The aim of this study was to examine the effects of close kinetic chain (CKC) exercise and open kinetic chain (OKC) exercise on muscle activation of the paretic lower limb and balance in chronic stroke subjects. METHODS: Thirty-three patients with chronic stroke of over 6 months were enrolled. They were randomly allocated to three groups: CKC exercise group (n = 11), OKC exercise group (n = 11), and control group (n = 11). CKC and OKC exercise groups were trained 5 times per week for 6 weeks. The control group maintained routine activities and did not participate in any regular exercise program. All subjects were measured on muscle activation of the paretic lower limb and balance. RESULTS: Muscle activation of rectus femoris (RF) and biceps femoris (BF) was significantly increased in both CKC exercise and OKC exercise groups, compared to the control group. However, muscle activation of gastrocnemius (GC) and tibialis anterior (TA) was significantly increased in only the CKC exercise group. Antero-posterior (A-P) and medio-lateral (M-L) sway velocities (both with EO and EC) were decreased with the application of CKC exercise. CONCLUSION: These findings indicate that the CKC exercise can improve lower limb muscle strength, and balance in chronic stroke, and it may carry over into an improvement in functional performance.