# Comparison of Dominant and Non-Dominant Muscle Function Recovery and Limb Symmetry After Achilles Tendon Repair: A Retrospective Study

## TL;DR

This study compares recovery of muscle function and balance after Achilles tendon surgery in dominant and non-dominant limbs, finding that dominant limbs recover better dynamic balance.

## Contribution

The study provides new insights into limb dominance effects on recovery after Achilles tendon repair.

## Key findings

- Both dominant and non-dominant limbs showed progressive improvement in range of motion and strength over 12 months.
- Dominant limbs achieved better dynamic balance recovery as measured by the Y-Balance Test at 12 months.
- Only the dominant limb group surpassed 90% limb symmetry in the Y-Balance Test at the final follow-up.

## Abstract

Background/Objectives: The Achilles tendon is the largest tendon in the human body; it is frequently ruptured during sports and other dynamic physical activities. The purpose of this study was to compare recovery patterns over time between injuries to the dominant (DMT) and non-dominant (NDMT) limbs, and to examine differences in the limb symmetry index (LSI) for the uninjured side. Methods: This study includes a retrospective analysis of individuals who completed a standard rehabilitation program for 12 months and had regular checkups every three months. The study sample comprised 17 patients with DMT injuries and 17 patients with NDMT injuries, all active male recreational participants who underwent surgical repair of an Achilles tendon rupture. Outcome measures included dorsiflexion range of motion (ROM), calf circumference, plantarflexion strength, hop test performance, and the Y-Balance Test (YBT). Results: Both groups demonstrated continuous, progressive improvement in ROM, plantarflexion strength, hop test distance, and YBT scores, showing a significant main effect of time (p < 0.05). Although DMT showed greater strength than NDMT at 6 and 9 months, this difference was no longer significant at 12 months (p > 0.05). In all three YBT directions, the DMT group achieved greater reach distances than the NDMT group at 12 months (p < 0.05). At the final follow-up, both groups exceeded 90% LSI in ROM, calf circumference, plantarflexion strength, and hop performance (p < 0.05). However, in the YBT, only the DMT group surpassed 90% LSI, whereas the NDMT group showed poorer recovery. Conclusions: ROM, calf circumference, and muscle strength ultimately showed no significant differences between groups, but dynamic balance recovery was superior in the DMT group. These findings suggest that clinicians and rehabilitation specialists should consider leg dominance when designing rehabilitation programs.