Military personnel with subacromial impingement syndrome do not show proprioception alteration: a single-blind paired case-control study

Abstract

Introduction: Subacromial impingement syndrome (SIS) is the most common condition in patients who complain of shoulder pain. In the scientific literature, there are studies that investigate the correlation of pain in SIS with proprioceptive alterations. However, there is no comprehensive evaluation of proprioception (including passive position sense, active position sense and kinesthesia) of the shoulder in patients with SIS using the isokinetic dynamometer comparing them to controls matched by age, gender, dominant side and affected shoulder, nor correlating this proprioceptive acuity with clinical information of these patients. Objective: To compare the proprioceptive function of the shoulder between patients with SIS and matched controls. Methods: This is an observational case-control study of 64 participants selected from the Physical-Functional Rehabilitation Service of the Brazilian Navy. The patients (GS) presented for physical therapy with a new episode of shoulder pain and diagnosed with SIS through the evaluation of a physical therapist. Controls (CG) had no history of shoulder pain and were individually matched by age, sex, and lateral dominance. All participants completed the numerical pain scale (NPS), scoring their pain from 0 to 10, and the Shoulder Pain and Disability Index (SPADI-Brazil) questionnaire. Then, a physical examination consisting of proprioceptive assessment through passive motion detection threshold (PMDT), passive position sense (PPS), and active position sense (APS) was performed. After this step, the craniocervical flexion test (CCFT) and the pectoralis minor index (PMI) were performed. The groups were compared in each investigated variable and the relationship between the variables was analyzed. Results: The mean age of the participants was 33 years (range: 26-40) and 42 (65.6%) were men. Patients with SIS do not present proprioceptive deficit. The results for each group were expressed as median, both groups did not present statistically significantly difference for any proprioceptive variable: LDMP lateral rotation (GC = 2.05; GS = 2.82; P = 0.253), LDMP medial rotation (GC = 2.13; GS = 2.47; P = 0.436), SPP lateral rotation (GC = 8.05; GS = 7.93; P = 0.898), SPP for medial rotation (GC = 3.75; GS = 3.82; P = 0.752), SPA lateral rotation (GC = 9.50; GS = 7.67; P = 0.957), SPA medial rotation (GC = 2.80; GS = 2.58; P = 0.904). There was no relationship between proprioception and cervical function, pectoralis minor index, pain intensity and functional capacity. Conclusion: Patients with SIS did not present proprioceptive alterations when compared with matched controls. The proprioceptive evaluation, cervical function and pectoralis minor shortening of these patients were not related to pain intensity and functional disability in the shoulder. Both groups did not present differences between cervical function and pectoralis minor shortening.