Mirror Training to Augment Cross-Education During Short-Term Limb Immobilisation

Periods of limb immobilisation lead to rapid declines in muscle strength and neural activity. Cross-education; a phenomenon where strength training one limb also strengthens the untrained limb; has significant rehabilitation potential, particularly for individuals recovering from unilateral injuries. However, the extent of cross-education remains modest. This project investigates whether mirror training, which involves observing the active limb’s movements in a mirror, can amplify the cross-education effect. Mirror training is believed to enhance motor learning by activating the mirror neuron system, potentially increasing corticospinal and reticulospinal excitability. This study will explore whether incorporating mirror training improves strength retention, neural activation, and overall motor function in immobilised limbs. Participants will undergo a two-week unilateral resistance training program with or without mirror feedback while the opposite limb remains immobilized. Neuromuscular changes will be assessed using high-density surface electromyography (HD-sEMG), transcranial magnetic stimulation (TMS), and functional near-infrared spectroscopy (fNIRS) to measure brain activation, muscle recruitment, and motor unit adaptations. The findings will provide new insights into neuroplasticity and rehabilitation strategies, offering an innovative, low-cost approach for preventing strength loss due to injury or immobilization. This research has direct applications in clinical rehabilitation, sports science, and neurophysiology.