Blood flow restriction exercise of the tibialis anterior in people with stroke: a preliminary study

Abstract

Background: Blood flow restriction exercise (BFR-E) could be a useful training adjunct for patients with weakness after stroke to augment the effects of exercise on muscle activity. We aimed to examine neurophysiological changes (primary aim) and assess patient perceptions (secondary aim) following BFR-E. Methods: Fourteen participants with stroke performed BFR-E (1 session) and exercise without blood flow restrictsion (Exercise only) (1 session), on two days, ≈7 days apart. In each session, two sets of tibialis anterior (TA) contractions were performed and electromyography (EMG) was recorded. Eight participants underwent transcranial magnetic stimulation (single-pulse stimulation, short interval intracortical inhibition (SICI), intracortical facilitation (ICF)) and peripheral electrical stimulation (maximal peak-to-peak M-wave (M-max)) of the TA before, immediately-after, 10-min-after and 20-min-after BFR-E and Exercise only. Numerical rating scores (NRS) for pain, discomfort, fatigue, safety, focus and difficulty were collected for all subjects (n = 14). Paired comparisons and linear mixed models assessed the effects of BFR-E and Exercise only. Results: No adverse events due to exercise were reported. There was no contraction-number × condition interaction for EMG amplitude during exercise (p = 0.15), or time × condition interaction for single-pulse stmulation, SICI, ICF or M-max amplitude (p = 0.34 to p = 0.97). There was no difference between BFR-E and Exercise only in NRS scores (p = 0.10 to p = 0.50). Conclusion: Using our training paradigm, neurophysiological parameters, feasibility, tolerability and perceptions of safety were not different between BFR-E and Exercise only. As participants were generally well-functioning, our results are not generalizable to lower functioning people with stroke, different (more intense) exercise protocols or longer term training over weeks or months.

Safety and efficacy of blood flow restriction exercise in individuals with neurological disorders: A systematic review

“…Furthermore, two studies collected information on delayed onset of muscle soreness 35,45 . In addition, muscle pain during and after training sessions was measured in five studies 35,41,44,45,47 . Blood pressure 33,34,36,37,41,44 and heart rate 33,34,36,41,42,44 responses during training were monitored in half ( n = 7) of the studies investigating the safety of BFRE, where two studies examined the prevalence of autonomic dysreflexia events in individuals with SCI 39,42 while also employing screening for deep vein thrombosis 41,44 .…”

“…Study characteristics are summarized in Table 1. The selected literature included four RCTs, 39,40,42,43 three randomized crossover trials, 35,46,47 two with‐in‐subject trials, 36,44 five case reports, 32,37,38,41,45 and two single‐subject research trials 33,34 …”

“…Twenty-seven studies were excluded for various reasons (summarized in Figure 1), leaving 16 studies to be included for the present systematic review. [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] One study exclusively concentrated on efficacy outcomes. 40 Three studies assessed both the efficacy and safety of BFRE, 39,42,43 while 12 studies examined selected safety aspects alone.…”

“…For the additional five domains, some concerns or a high risk of bias were scored for all five studies. 35,36,44,46,47 The risk-of-bias assessment of Case Reports revealed an overall fairly low risk of bias or some concerns for a majority of domains. One study did not present the patient's history as a timeline and two additional studies had a high risk of bias due to a lack of description of participants' post-intervention clinical conditions.…”

Effectiveness of Blood Flow Restriction in Neurological Disorders: A Systematic Review

“…There are several therapeutic possibilities, including conservative treatment, with the goal of enhancing daily activities, avoiding deformities, preserving joint motion, relieving pain, and reducing muscle tone [ 14 ]. While most of the investigations on BFR training have focused on healthy populations [ 15 , 16 ], some case or observational studies have been performed on BFR in patients with neurological problems, such as Parkinson’s disease [ 17 , 18 ], multiple sclerosis [ 19 , 20 , 21 , 22 ], spinal cord injury [ 7 ] and stroke [ 23 ].…”