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Updated: Jul 10, 2026

A Standardized Method for Measurement of Elbow Kinesthesia
Published on: October 10, 2020
Muscle contribution to elbow joint valgus stability.
Fang Lin1, Navjot Kohli, Sam Perlmutter
1Department of Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, IL 60611, USA.
The flexor carpi ulnaris (FCU), flexor digitorum superficialis (FDS), and flexor carpi radialis (FCR) muscles dynamically stabilize the elbow, with the FCU providing primary support against valgus stress. The extensor carpi ulnaris (ECU) and extensor digitorum communis (EDC) increase valgus strain.
Area of Science:
- Orthopedics
- Biomechanics
- Sports Medicine
Background:
- Repetitive valgus stress on the elbow can lead to medial ulnar collateral ligament (MUCL) injury, particularly in overhead athletes.
- The flexor-pronator mass (FPM) and extensor-supinator mass muscles play a role in elbow valgus stability.
Purpose of the Study:
- To determine the individual contribution of FPM and extensor-supinator muscles to elbow valgus stability.
- To assess the effect of muscle loading on MUCL strain and elbow kinematics at 45 and 90 degrees of flexion.
Main Methods:
- Eight fresh-frozen elbow specimens were tested with intact muscles.
- Individual muscles of the FPM and extensor-supinator mass were loaded to measure MUCL strain and elbow kinematics.
- Measurements were repeated after transecting the MUCL.
Main Results:
- Loading the flexor carpi ulnaris (FCU), flexor digitorum superficialis (FDS), and flexor carpi radialis (FCR) significantly reduced MUCL strain.
- The FCU provided the greatest MUCL relief among the flexor muscles.
- Loading the extensor carpi ulnaris (ECU) and extensor digitorum communis (EDC) increased MUCL strain and induced valgus movement.
Conclusions:
- FCU, FDS, and FCR act as dynamic stabilizers, with FCU being the primary dynamic stabilizer for elbow valgus.
- ECU and EDC may increase elbow valgus stress and MUCL strain.
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