Hand strengthening exercises in chronic stroke patients: Dose-response evaluation using electromyography

Area of Science:

• Rehabilitation Medicine
• Neuroscience
• Exercise Physiology

Background:

• Stroke survivors often experience impaired hand function.
• Muscle strengthening is crucial for motor recovery after stroke.
• Elastic resistance exercises offer a accessible method for rehabilitation.

Purpose of the Study:

• To evaluate the effectiveness of finger flexion and extension strengthening exercises using elastic resistance in chronic stroke patients.
• To compare muscle activity during different resistance levels for these exercises.

Main Methods:

• A cross-sectional study involving 18 chronic stroke patients with hemiparesis.
• Participants performed finger flexion and extension exercises with three elastic resistance levels (easy, moderate, hard).
• Surface electromyography (EMG) of flexor digitorum superficialis (FDS) and extensor digitorum (ED) muscles was recorded and normalized.

Main Results:

• Paretic hand grip strength was significantly lower than the non-paretic hand (7.8 kg vs 39.2 kg).
• Finger flexion exercises elicited higher muscle activity in both ED (15% vs 30%) and FDS (24% vs 37%) compared to extension exercises.
• No significant dose-response relationship was found between resistance level and muscle activity during flexion exercises.

Conclusions:

• Finger flexion exercises demonstrate superior muscle activation in both forearm flexor and extensor muscles compared to extension exercises in chronic stroke patients.
• Higher elastic resistance during finger flexion did not proportionally increase muscle activity.
• Finger flexion exercises are recommended for maximizing muscle activation, while finger extension may focus on neuromuscular control improvement.