Effects of Blood Flow Restriction Walking on Distal and Contralateral Lower Limb Muscles: A Nonrandomized Clinical Trial With a Within-Subject Approach

Abstract

Background:

Blood flow restriction (BFR) training effectively improves strength in muscles directly subjected to occlusion. Secondary effects on distal and contralateral muscles remain underexplored.

Hypothesis:

A walking training program plus BFR applied to the upper thigh enhances muscle strength in distal muscles of the lower leg.

Study Design:

Nonrandomized controlled clinical trial with a within-subject approach.

Level of Evidence:

Level 1.

Methods:

A total of 20 male and 12 female adults (31.1 ± 9.5 years) with ≥10% strength asymmetry in knee extensors completed 3 weekly sessions over 12 weeks. A cuff inflated at 90% of total occlusion pressure was applied to the weaker limb (exercised segment [ES]); the stronger limb served as control segment (CS). Outcomes assessed pre- and postintervention included ankle plantarflexor and dorsiflexor strength and muscle thickness (MT) (medial gastrocnemius [MG] and tibialis anterior [TA]) using isometric testing and ultrasound.

Results:

Strength gains were identified after training in the ES and CS for the MG and TA muscles (P < 0.005 pre-to-post comparisons). In the ES, the plantarflexor and dorsiflexor torque increased from 85.6 N·m to 111.7 N·m and from 34.5 N·m to 39.6 N·m, respectively. In the CS, torque increased from 93.1 N·m to 110.5 N·m (plantarflexors) and from 35.5 N·m to 40.3 N·m (dorsiflexors). Relative improvements were greater in the ES (plantarflexor, +30.4%; dorsiflexor, +14.8%) than the CS (plantarflexor, +18.7%; TA, +13.6%), although no interactions were observed (P > 0.05). MT showed nonsignificant variation (P > 0.05). In the ES, the MG changed from 1.93 cm to 2.04 cm and TA from 2.06 cm to 2.33 cm. In the CS, the MG remained stable (1.99 cm to 2.02 cm), and TA varied from 2.12 cm to 2.35 cm.

Conclusion:

Walking combined with BFR targeting the upper thigh improves strength in distal muscles of the lower leg, with notable gains in both the occluded and contralateral segments. Neural adaptations likely account for the observed strength increases.

Clinical Relevance:

BFR walking is an effective, low-impact intervention to enhance lower-limb muscle strength, with potential applications in rehabilitation and training for people with asymmetry or muscle weakness.