Composite active range of motion (CX) and relationship with active function in upper and lower limb spastic paresis.

OBJECTIVE

The aim of this study is to evaluate a novel composite measure of active range of motion (X) and determine whether this measure correlates with active function.

DESIGN

Post hoc analysis of two randomized, placebo-controlled, double-blind studies with open-label extensions exploring changes in active function with abobotulinumtoxinA.

SETTING

Tertiary rehabilitation centers in Australia, Europe, and the United States.

SUBJECTS

Adults with upper ( = 254) or lower ( = 345) limb spastic paresis following stroke or brain trauma.

INTERVENTIONS

AbobotulinumtoxinA (⩽5 treatment cycles) in the upper or lower limb.

MAIN MEASURES

X was used to calculate a novel composite measure (CX), defined as the sum of X against elbow, wrist, and extrinsic finger flexors (upper limb) or soleus and gastrocnemius muscles (lower limb). Active function was assessed by the Modified Frenchay Scale and 10-m comfortable barefoot walking speed in the upper limb and lower limb, respectively. Correlations between CX and active function at Weeks 4 and 12 of open-label cycles were explored.

RESULTS

CX and active function were moderately correlated in the upper limb ( < 0.0001-0.0004,  = 0.476-0.636) and weakly correlated in the lower limb ( < 0.0001-0.0284,  = 0.186-0.285) at Weeks 4 and 12 of each open-label cycle. Changes in CX and active function were weakly correlated only in the upper limb (Cycle 2 Week 12,  = 0.0160,  = 0.213; Cycle 3 Week 4,  = 0.0031,  = 0.296). Across cycles, CX improvements peaked at Week 4, while functional improvements peaked at Week 12.

CONCLUSION

CX is a valid measure for functional impairments in spastic paresis. CX improvements following abobotulinumtoxinA injection correlated with and preceded active functional improvements.