Shoulder physical activity, functional disability and task difficulties in patients with stiff shoulders: interpretation from RT3 accelerator

Accelerometry as an objective measure of upper-extremity activity

Most studies evaluating the effectiveness of treatments targeting shoulder pathologies use subjective outcome measures such as self-administered questionnaires. To date, there are no validated tools that objectively measure shoulder-specific functional activity. The purpose of this study was to validate wearable accelerometers as an objective proxy for shoulder activity. Ten healthy volunteers wore accelerometers placed at both wrists, the dominant upper arm and the chest while performing standardised shoulder and non-shoulder activities. Recorded tridimensional acceleration was computed into activity counts for epochs of 10 s. Receiver operating characteristics (ROC) curves were built to determine the optimal configuration to classify shoulder-type activities. For single accelerometer placement, the area under the ROC curve (AUC) was optimal for the 10-s epoch (AUC = 0.779) using the wrist placement, with a sensitivity of 94.1% and specificity of 67.5%. The combined upper arm and chest placement had an AUC of 0.985 (94.8% sensitivity, 94.8% specificity). Dual-accelerometer placement (upper arm and chest) is the optimal configuration to classify shoulder activity. However, a sole wrist-based accelerometer can be used as an objective proxy for shoulder activity in long-term unsupervised monitoring with excellent sensitivity and acceptable specificity.

Relationship of shoulder activity and skin intrinsic fluorescence with low level shoulder pain and disability in people with type 2 diabetes

AIM

People with type 2 diabetes (T2DM) have a high incidence of musculoskeletal disorders thought to be influenced by high non-enzymatic advanced glycated end-products (AGEs). The goals of this study were to determine differences in shoulder activity level and AGEs in people with T2DM compared to matched controls, and to determine factors associated with shoulder pain and disability.

METHODS

Eighty-one participants, T2DM (n=52) and controls (n=29), were examined for magnitude and duration of shoulder activity (measured using accelerometers), skin intrinsic florescence (SIF) as a surrogate measure of AGE level, and the Shoulder Pain and Disability Index (SPADI) as a self-report of shoulder pain and disability.

RESULTS

Compared with controls, T2DM participants had 23% less shoulder activity (p=0.01), greater SIF level (3.6±1.7 vs 2.7±0.6AU, p=0.01), less shoulder strength (p<0.05), and the duration of their shoulder activity was moderately associated (r=0.40; p<0.01) with reported shoulder pain and disability. Shoulder pain and disability were not related to SIF level.

CONCLUSIONS

Persons with T2DM have higher SIF levels and shoulder symptoms and disability indices than controls. Research is needed to determine if a shoulder mobility intervention to increase strength and mobility can help decrease shoulder pain and disability.