Efficacy of Standardized Physical Therapy and Axillary Motor Stimulation for Chronic Shoulder Pain: A Randomized Controlled Trial

Abstract

Introduction: Many with chronic shoulder pain due to subacromial impingement syndrome have persistent pain. Motor stimulation is an emerging treatment that may increase efficacy of physical therapy as part of a multimodal treatment.

Objective: The aim of the study was to evaluate the efficacy of physical therapy and axillary motor stimulation among participants with chronic subacromial pain.

Design: This study used a dual-site, randomized, participant and assessor-blinded, placebo-controlled trial.

Participants: One hundred sixteen participants with chronic shoulder pain due to subacromial impingement syndrome.

Interventions: Participants were randomized to receive physical therapy + motor stimulation (n = 60) or physical therapy + no stimulation (n = 56).

Results: The primary outcome was the worst pain in the past week (Brief Pain Inventory, Short Form, question 3). Secondary outcome measures included other questions of the Brief Pain Inventory, the Shoulder Pain and Disability Index, Functional Assessment Test-Hand/Neck/Shoulder/Arm, and Short-Form 36. Both groups experienced significant improvements over time in all assessed outcome measures. There was not a significant difference between the groups. No significant adverse events related to the interventions were observed.

Conclusions: For those with chronic subacromial impingement syndrome, physical therapy + motor stimulation is efficacious in reducing shoulder pain and improving function, although physical therapy alone may be sufficient if patients can complete a standardized protocol.

Trial registration: ClinicalTrials.gov NCT03752619.

Keywords: Chronic Pain; Physical Therapy; Randomized Controlled Trials; Shoulder Pain.