The clinical impact of the presence or absence of the fifth finger flexor digitorum superficialis on grip strength.

Previous studies have determined abnormalities in the fifth small finger flexor digitorum superficialis (FDS) tendons as interconnected (common) to the fourth finger (FDS) or absent. This study examined the effect of FDS-absent and FDS-common presentations of the fifth finger on grip strength in a mixed-gender group of rehabilitation science students and faculty members from the Medical University of South Carolina. This study evaluated 171 subjects. After controlling for gender, age, and hand dominance, the grip strength of subjects in the FDS-absent group was 6.9 lb weaker than the FDS-common group and 8.14 lb weaker than the FDS-independent group. The common group was 1.2 lb weaker than the normal group. Absence of the FDS occurred in 18.6% of female subjects and 15.3% of male subjects. Our findings suggest that hand therapists should expect lower results when measuring grip strength of FDS-absent or FDS-common individuals.