Concurrent neuromechanical and functional gains following upper-extremity power training post-stroke

Area of Science:

• Neurorehabilitation
• Motor Recovery
• Stroke Rehabilitation

Background:

• Repetitive task practice is a cornerstone of neuroplasticity following stroke.
• Hemiparetic weakness can limit effective movement practice and recovery.
• The efficacy of high-intensity power training in upper-extremity rehabilitation remains under investigation.

Purpose of the Study:

• To investigate the effects of power training on upper-extremity motor function recovery post-stroke.
• To compare the efficacy of combined functional task practice and power training (HYBRID) versus functional task practice (FTP) alone.
• To assess the retention of functional and neuromechanical gains 6 months post-intervention.

Main Methods:

• A crossover design study involving 19 individuals with chronic hemiparesis.
• Participants underwent both FTP and HYBRID interventions in a randomized order.
• Evaluations included motor function tests (WMFT-FAS), spasticity measures (Ashworth Scale), and neuromechanical assessments (joint torques, EMG, stretch reflexes).

Main Results:

• The HYBRID intervention led to significantly greater improvements in the primary outcome (WMFT-FAS) compared to FTP.
• A higher proportion of participants achieved minimally important differences (MID) with HYBRID, with sustained improvements at 6 months.
• HYBRID training significantly increased maximal isometric joint torque, agonist EMG, and peak power, with retained benefits at 6 months. Stretch reflex modulation also improved.

Conclusions:

• Combined functional task practice and power training (HYBRID) yields superior functional and neuromechanical gains post-stroke compared to FTP alone.
• HYBRID training promotes neural adaptations, evidenced by improved stretch reflex modulation and neuromuscular activation.
• High-intensity training is safe and effective in neurorehabilitation, showing no exacerbation of spasticity or adverse events.