Relation between the upper extremity synergistic movement components and its implication for motor recovery in poststroke hemiparesis.

BACKGROUND: Synergy is a functional linkage of muscles during voluntary motor action. In poststroke hemiparesis, synergistic movements get disorganized in the form of stereotyped behaviors. Furthermore, there is a linkage between the movement components of the synergies, which should be understood for focused motor rehabilitation. OBJECTIVE: To find the relationship between the synergistic motor behavior and recovery of the individual movement in chronic poststroke hemiparetic subjects. METHOD: A prospective, cross-sectional, observational study was conducted at an outpatient occupational therapy unit of a rehabilitation institute. A convenience sample of 30 chronic poststroke hemiparetic subjects (25 male and 5 female; 16 left sided and 14 right sided) was assessed using the Fugl-Meyer assessment (FMA) and Brunnstrom recovery stages of arm (BRS-A) and hand (BRS-H). RESULTS: The mean poststroke duration of the subjects was 40.9 months. There were significantly higher scores ( P < .001) for BRS-A (4.13 ± 1.07) and FMA upper arm (29.03 ± 4.31) as compared to BRS-H (2.47 ± 1.45) and FMA wrist and hand (11.50 ± 5.88), respectively. Very high correlation ( r = 0.9 to 1.0; P < .05) was found between the 2 components of FMA (wrist circumduction and spherical grasp). Moderate ( r = 0.5 to 0.69; P < .05) to high ( r = 0.7 to 0.89; P < .05) correlation was found between many components of FMA (flexor synergy, extensor synergy, movement combining synergies, movement out of synergy, upper arm, and wrist-hand components). CONCLUSION: Many upper extremity movement components of the paretic side were related to one another. The components may be used for motor rehabilitation in order of their strength of association. The concept of synergistic linkage may be applied for motor training of the upper limb at a particular stage of the recovery.