Impact on efferent neural drive, force-generating capacity, and functional performance
J. Helgerud, S. N. Thomsen, J. Hoff, A. Strandbråten, G. Leivseth, R. Unhjem, E. Wang
Parkinson’s disease (PD) is a progressive degenerative disorder of the nervous system, originating from the brain. Patients with PD display profound reductions in maximal muscle strength and rate of force development (RFD). In addition, PD patients suffer from functional disability, impaired work economy, and increased risk of falls and fracture.
Maximal strength training (MST), carried out at ~90% of one repetition maximum (1RM) with maximal intended concentric contraction velocity, istailored to target the nervous system and shown to be more effective in improving strength than conventional strength training carried out at ~70 –75% of 1RM. MST-induced improvements in strength are shown to be accompanied by enhanced neural drive to maximally contracting musculature in both young and old individuals and in other patient groups with neurological disorders. Ultimately, improvements in lower extremity strength following MST are typically shown to result in improved physical function.
The aim of the present study was to investigate if MST could improve the effects of conventional treatment of PD patients, consisting of physical activity with low-to-moderate intensity. We randomly assigned 22 PD patients to conventional rehabilitation with or without maximal strength training (MST) performed as leg press and chest press at ~90% of one repetition maximum (1RM), five times per week for 4 weeks.
Results revealed that only MST improved 1RM leg press and chest press, plantar flexion maximal voluntary contraction, and RFD. These improvements were accompanied by an increased neural drive to maximally contracting musculature, improved stair climbing, timed up andgo, and self-perceived improvement in health and social activities functioning. No changes were observed in the control group.
Conclusion: The present study demonstrates that 4 weeks of MST may effectively improve skeletal muscle strength, neural drive, and functional performance in elderly PD patients. In contrast, the present regime of conventional physical treatment did not alter these measures, and questions the effectiveness of traditional rehabilitation exercises. These findings advocate that high-intensity strength training should be implemented as an adjunct therapy in the rehabilitation of PD. Not only may MST improve neuromuscular performance, it may also attenuate functional impairments typically reported in this population.
Read the full study: https://pubmed.ncbi.nlm.nih.gov/32790593/