Article Document Academic Article Information Content Entity Continuant Continuant Journal Article Entity Entity Generically Dependent Continuant 2025-05-11T07:20:21 RDF description of First dorsal interosseous muscle contraction results in radiographic reduction of healthy thumb carpometacarpal joint - http://repository.healthpartners.com/individual/document-rn38444 Radiography 23672 document-rn38444 40964 2025-01-31T22:52:05.028-06:00 First dorsal interosseous muscle contraction results in radiographic reduction of healthy thumb carpometacarpal joint 10.1016/j.jht.2015.06.002 Arthritis public 4 <p>INTRODUCTION: Hand therapists selectively strengthen the first dorsal interosseus (FDI) to stabilize arthritic joints yet the role of the FDI has not yet been radiographically validated. PURPOSE: To determine if FDI contraction reduces radial subluxation (RS) of the thumb metacarpal (MC). <br>METHODS: Fluoroscopy was used to obtain true anterior-posterior radiographs of non-arthritic CMC joints: 1) at rest, 2) while stressed and 3) while stressed with maximal FDI contraction. Maximal FDI strength during CMC stress and thumb MC RS and trapezial articular width were measured. The ratio of RS to the articular width was calculated. <br>RESULTS: Seventeen participants (5 male, 12 female) participated. Subluxation of a stressed CMC significantly reduced and the subluxation to articular width ratio significantly improved after FDI activation. <br>CONCLUSIONS: Contraction of the FDI appears to radiographically reduce subluxation of the healthy thumb CMC joint. Further exploration on the FDI's reducibility and its carry-over effects in arthritic thumbs is needed. <br>LEVEL OF EVIDENCE: 4.<p> 28 Hand Orthopedics Journal of Hand Therapy