Related Experiment Video
Updated: May 29, 2026
10:07
Measurement of Dynamic Scapular Kinematics Using an Acromion Marker Cluster to Minimize Skin Movement Artifact
Published on: February 10, 2015
Measuring scapular kinematics during arm lowering using the acromion marker cluster.
M B Warner1, P H Chappell, M J Stokes
1Faculty of Health Sciences, University of Southampton, Southampton, UK. m.warner@soton.ac.uk
Human Movement Science
|August 31, 2011
Summary
The acromion marker cluster (AMC) method reasonably measures scapular kinematics during arm lowering, with minor inaccuracies in frontal plane movements. This technique offers a viable option for assessing shoulder complex motion.
Area of Science:
- Biomechanics
- Kinesiology
- Orthopedics
Background:
- Scapular kinematics are crucial for shoulder function.
- Accurate measurement of scapular motion is essential for clinical assessment and research.
- The acromion marker cluster (AMC) is a non-invasive method for tracking scapular orientation.
Purpose of the Study:
- To evaluate the validity of the acromion marker cluster (AMC) method for measuring scapular kinematics during the arm lowering (eccentric) phase.
- To compare AMC measurements with a scapular locator (SL) during arm lowering across different planes of motion.
Main Methods:
- Twenty-six participants performed arm elevation and lowering in sagittal, frontal, and scapular planes.
- Scapular orientation was recorded using both AMC and a scapular locator (SL) at 30° increments.
- Root mean square error (RMSE) was calculated to assess differences between AMC and SL measurements.
Main Results:
- No significant differences were found between AMC and SL for sagittal and scapular plane arm lowering.
- The AMC significantly underestimated upward rotation (max RMSE = 6.0°) and overestimated posterior tilt (max RMSE = 7.2°) in the frontal plane during arm lowering.
- Observed RMSE values were comparable to those reported in previous studies and during arm elevation.
Conclusions:
- The AMC method provides a reasonable assessment of scapular kinematics during the arm lowering phase.
- While minor discrepancies exist in the frontal plane, the AMC's overall accuracy supports its use in clinical and research settings.
- Further validation may be needed for precise frontal plane kinematic analysis during eccentric shoulder movements.
Related Concept Videos
01:23Muscles of the Shoulder
The muscles surrounding the shoulder girdle, including the clavicle and scapula, primarily stabilize the scapula. This stable base allows other muscles to move the humerus effectively. Scapular movements often mirror those of the humerus and extend its range of motion. For instance, raising the arm above the head would not be feasible without simultaneous upward rotation of the scapula.
Anterior Thoracic Muscles
The anterior thoracic muscles include the serratus anterior, subclavius, and...
Anterior Thoracic Muscles
The anterior thoracic muscles include the serratus anterior, subclavius, and...
01:31Muscles that Move the Arm
Nine muscles are involved in arm movements. Two of these, the pectoralis major and latissimus dorsi, originate from the axial skeleton and are called axial muscles. The other seven originate from the scapula and are called the scapular muscles.
The pectoralis major has two origins. Its clavicular head originates on the medial half of the clavicle. In contrast, the sternocostal head originates on the costal cartilages of ribs 1-6, the sternum, and the aponeurosis of the external oblique of the...
The pectoralis major has two origins. Its clavicular head originates on the medial half of the clavicle. In contrast, the sternocostal head originates on the costal cartilages of ribs 1-6, the sternum, and the aponeurosis of the external oblique of the...