Should we think about wrist extensor after flexor tendon repair?

Area of Science:

• Biomechanics and Rehabilitation Science
• Orthopedic Surgery
• Hand Therapy

Background:

• Flexor tendon repair in the hand requires comprehensive rehabilitation to restore function.
• Wrist extensor muscles play a crucial synergistic role in effective handgrip.
• Understanding muscle activation patterns post-surgery is vital for optimizing recovery.

Purpose of the Study:

• To evaluate wrist extensor muscle activity during gripping in patients after flexor tendon repair.
• To correlate wrist extensor muscle activity with wrist motion during gripping.
• To identify potential imbalances in muscle activation during the rehabilitation phase.

Main Methods:

• A cross-sectional clinical measurement study involving 11 patients post-flexor tendon repair and 11 healthy volunteers.
• Electrogoniometry and surface electromyography (EMG) were used to analyze wrist range of motion and muscle activity (extensor carpi radialis, flexor digitorum superficialis).
• Participants performed standardized isometric gripping tasks.

Main Results:

• Patients demonstrated a co-activation deficit between wrist extensors and finger flexors during gripping.
• A moderate correlation (r = 0.32) between wrist range of motion and extensor carpi radialis activity was observed in the injured group.
• 65% of patients with associated nerve repair showed regular or poor total active motion scores.

Conclusions:

• Wrist extensors are important synergists for handgrip, but imbalances can occur after flexor tendon repair.
• Rehabilitation protocols could benefit from incorporating exercises that emphasize synergistic wrist motion.
• Further research with early active rehabilitation is warranted to explore these findings.