Shoulder-specific rehabilitation combined with aerobic exercises versus solely shoulder-specific rehabilitation in patients with type 2 diabetes mellitus: study protocol for a randomized controlled superiority trial

BACKGROUND: Musculoskeletal disorders are very common in patients with diabetes mellitus (DM). The upper limb is one of the regions that is most frequently affected generally presenting limited joint mobility, pain, and a decreased muscle strength. Most clinical trials with a focus on shoulder musculoskeletal rehabilitation are carried out in patients who do not present DM. Thus, the purpose of the present study is to compare the effects of two distinct treatment protocols (conventional shoulder musculoskeletal rehabilitation combined with aerobic exercises versus solely conventional shoulder musculoskeletal rehabilitation) on shoulder pain, function, strength, kinematics, and supraspinatus tendon thickness in patients with type 2 DM after 12 weeks of intervention and a subsequent follow-up at week 20. METHODS: A randomized controlled superiority trial will be conducted. Participants with a clinical diagnosis of type 2 DM of both sexes, age between 40 and 70 years, presenting shoulder pain will be randomly assigned to one of the following groups: (1) conventional shoulder musculoskeletal rehabilitation combined with aerobic exercises; (2) solely conventional shoulder musculoskeletal rehabilitation. All individuals will be evaluated before starting the treatment protocol (baseline) and at the end of treatment (post 12 weeks) and as a follow-up at 20 weeks. The shoulder function assessed by the SPADI (Shoulder Pain and Disability Index) questionnaire will be considered as primary outcome; the secondary outcome will be shoulder pain, measured with NPRS scales. Other outcomes will include range of motion, measured using a digital inclinometer; isometric shoulder muscle strength, measured using a manual muscle dynamometer; shoulder kinematics, measured using three-dimensional inertial units measurement; supraspinatus tendon thickness, measured using an ultrasound; AGE accumulation, using a skin autofluorescence measurement; and HbA1c (hemoglobin a1c), fasting glucose and lipid profile measured by a simple blood test. DISCUSSION: DM is a highly prevalent disease and a public health problem worldwide, and the upper extremity musculoskeletal disorders in DM are barely recognized and largely underestimated. In this way, it would be interesting to analyze if the combination of aerobic exercises with conventional musculoskeletal rehabilitation protocols could generate better results in the functionality, pain, mobility and an improvement in the biochemical aspects related to the hyperglycemia of these patients compared to solely the conventional musculoskeletal rehabilitation. TRIAL REGISTRATION: ClinicalTrials.gov NCT04817514. Registered on March 26, 2021.