Does high frequency exercise or electrical muscle stimulation improve strength and function in non-weight bearing, older patients? The PAIVE pilot randomised trial.

Abstract

Background: Older patients who are non-weightbearing/touch-weightbearing (NWB/TWB) following a lower limb fracture often receive limited physiotherapy until this restriction is removed. It is unknown whether interventions such as higher frequency exercise or Neuromuscular Electrical Stimulation (NMES) effectively maintain quadriceps strength and patient function. The primary aim of this pilot trial was to evaluate the feasibility of delivering two alternative interventions and obtaining selected outcome measures.

Methods: Twenty-four people with a lower limb fracture and NWB/TWB restriction were recruited on admission to a subacute ward at Western Health (a major metropolitan public health service in Melbourne). Participants were randomly allocated to receive either low frequency physiotherapy (n = 8), high frequency physiotherapy (n = 8) or NMES (n = 8). Interventions were delivered during the NWB/TWB phase. The primary outcomes were trial feasibility and safety; determined by adverse events. Quadriceps strength (assessed using a dynamometer), and function were measured at baseline, completion of NWB/TWB restriction, and on hospital discharge.

Results: Recruitment was paused twice due to the COVID-19 pandemic: 145 people were screened; 43 eligible and 24 recruited. Retention rate was high, with only two participants withdrawing due to acute medical reasons. Twenty-one out of 24 participants successfully completed their intervention sessions, with 91% of scheduled sessions delivered. Outcome measurement completion was 100% at baseline, 83% at completion of NWB/TWB restriction, and 83% on hospital discharge. While the study was not powered to determine effectiveness, the high frequency and NMES groups demonstrated higher ratios of quadriceps strength (affected / unaffected limb); compared to the low frequency group at discharge.

Conclusion: The trial protocol was feasible and safe. Results indicate there is a potential for high frequency exercise or NMES to be more effective at maintaining muscle strength compared to low frequency exercise. A fully powered randomised controlled trial to explore the effectiveness and cost of these interventions is warranted.