Effects of motor imagery on hand function during immobilization after flexor tendon repair

OBJECTIVE: To determine whether motor imagery during the immobilization period after flexor tendon injury results in a faster recovery of central mechanisms of hand function.

DESIGN: Randomized controlled trial.

SETTING: Tertiary referral hospital.

PARTICIPANTS: Patients (N=28) after surgical flexor tendon repair were assigned to either an intervention group or a control group.

INTERVENTION: Kinesthetic motor imagery of finger flexion movements during the postoperative dynamic splinting period.

MAIN OUTCOME MEASURES: The central aspects of hand function were measured with a preparation time test of finger flexion in which subjects pressed buttons as fast as possible following a visual stimulus. Additionally, the following hand function modalities were recorded: Michigan Hand Questionnaire, visual analog scale for hand function, kinematic analysis of drawing, active total motion, and strength.

RESULTS: After the immobilization period, the motor imagery group demonstrated significantly less increase of preparation time than the control group (P=.024). There was no significant influence of motor imagery on the other tested hand function (P>.05). All tests except kinematic analysis (P=.570) showed a significant improvement across time after the splinting period (P</=.001).

CONCLUSIONS: Motor imagery significantly improves central aspects of hand function, namely movement preparation time, while other modalities of hand function appear to be unaffected.