Flexors activity of affected upper extremity in stroke patients during different standing conditions and their relationships with clinical scales: a cross-sectional study.

Purpose: To explore the flexors activity of affected upper extremity in stroke patients during different standing conditions and their relationships with clinical scales. Materials and methods: Sixteen stroke patientswere recruited, all subjects stood on balance equipment with four different standing postures. The electromyogram (EMG) simultaneously recorded the muscle activity of bilateral biceps brachii, triceps brachii, flexor carpi radialis and extensor carpi radialis and their integrated electromyogram were figured out the contraction rate of elbow flexors(biceps brachii/triceps brachii) and wrist flexors(flexor carpi radialis/extensor carpi radialis). All subjects were assessed using Fugl-Meyer Assessment of the Upper Extremity (FMA-UE), Berg Balance Scale (BBS), Barthel Index (BI) and Modified Ashworth Scale (MAS). Results: The contraction rate of affected elbow flexors in the condition of feet together on soft surface was significantly higher than that in the condition of feet separatedon hard surface (P < 0.05). The contraction rate of affected elbow flexors in four standing conditions tended to increase, all the values of which were greater than numerical value1. The difference in the contraction rate of elbow flexor between the affected side and the unaffected side was statistically significant (P < 0.05). No correlation was observed between the contraction rate of the elbow flexor and the results of MAS, FMA-UE, BBS and BI regardless of the standing conditions. Conclusions: The contraction rates of elbowflexor in the affected side increase with the difficulty in different standing postures,and it may be a good index to reflect the changes of muscle tone in postural control.