Related Experiment Video
Updated: Jul 12, 2026
10:07
Measurement of Dynamic Scapular Kinematics Using an Acromion Marker Cluster to Minimize Skin Movement Artifact
Published on: February 10, 2015
Identifying rotator cuff disorders through shoulder movement quality: An exploratory study using a single inertial
Koyu Horibata1, Shinichi Kawamoto1, Daiki Nohara1
1Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Clinical Biomechanics (Bristol, Avon)
|July 9, 2026
Summary
Movement smoothness measured by SPARC using a wrist IMU can help differentiate rotator cuff disorders from other shoulder conditions. This objective method shows promise for clinical assessment and telerehabilitation.
Area of Science:
- Biomechanics
- Orthopedics
- Medical Technology
Background:
- Shoulder movement quality assessment is crucial for diagnosing rotator cuff disorders versus other shoulder conditions.
- Objective quantification of movement smoothness can aid in differentiating these conditions.
- Spectral Arc Length (SPARC) derived from Inertial Measurement Units (IMUs) offers a potential method for this assessment.
Purpose of the Study:
- To investigate differences in shoulder movement smoothness between rotator cuff disorders and other shoulder disorders.
- To evaluate the potential of SPARC from a single wrist-mounted IMU for objective disorder identification.
- To explore the relationship between movement smoothness and subjective pain measures.
Main Methods:
- An exploratory cross-sectional study involving thirty older adults with shoulder disorders.
- Classification of participants into rotator cuff disorder or other shoulder disorder groups by physical therapists.
- Recording angular velocity during shoulder flexion and abduction using a wrist-mounted IMU.
- Quantifying movement smoothness with SPARC and comparing it between groups alongside Numerical Rating Scale (NRS) pain scores.
Main Results:
- The rotator cuff disorder group exhibited significantly lower SPARC values during abduction.
- Numerically lower SPARC values were observed during flexion, though not statistically significant.
- Movement smoothness (SPARC) showed potential for distinguishing between groups (AUCs 0.70-0.74), unlike NRS pain scores.
- Movement smoothness appears to capture functional impairments not reflected in subjective pain.
Conclusions:
- Movement smoothness quantified by SPARC from a single IMU shows potential for differentiating rotator cuff disorders from other shoulder disorders.
- This objective, low-cost approach may serve as a complementary tool for shoulder function assessment.
- The method is suitable for clinical practice, home-based evaluation, and telerehabilitation.
