Limb Dominance Effects On Seated Single Arm Shot Put Limb Symmetry Indices Following Shoulder Rehabilitation

Abstract

The seated single arm shot put test (SSASPT) is one of the few upper extremity functional performance tests (UEFPT) available with good psychometric properties to assist clinicians with return to activity (RTA) decisions. Previous investigations have demonstrated SSASPT limb symmetry indices (LSI) in healthy persons to range from 103% to 111%, favoring the dominant (D) limb. Typically, most clinical RTA guidelines recommend that an injured shoulder achieve a 90-100% UEFPT LSI. To date, SSASPT LSI have not been examined in patients with shoulder pathologies. PURPOSE: To evaluate a LSI in patients being discharged from rehabilitation following shoulder injuries or surgeries. We hypothesized there would be LSI differences between the D and nondominant (ND) limbs. METHODS: Six Board Certified Clinical Specialist Physical Therapists who regularly use SSASPT as part of their RTA criteria from 6 different clinical sites provided SSASPT scores on 78 patients being discharged from rehabilitation following shoulder injury or surgery. LSI were computed from the SSASPT scores (injured/uninjured *100) and patients were grouped according to whether the involved shoulder was on the D (n = 44) or ND (n = 34) limb. An independent t-test compared LSI between the two groups while a chi square compared the number of patients in each group with LSI <90%, 90-100%, 100-110% and > 110%. RESULTS: LSI for the D shoulder group (105.0 ± 11.0%) were significantly greater (P < .001, 95% CIdiff = 10.8 to 21.2%) than the ND group (89.0 ± 12.1%). Significant group differences (P < .001) were also revealed in the LSI intervals. While 55.9% of the ND shoulder patients demonstrated LSI <90%, 77.3% of D shoulder patients demonstrated LSI >100%. CONCLUSIONS: The results supported our hypothesis. Based on the significant limb LSI differences, we recommend when establishing RTA criteria for the SSASPT following shoulder injury or surgery, the D versus ND limb be considered. Specifically, the D limb should strive to be ~105%, whereas the ND limb should be ~100%. The results also indicate the ND arm may require more rehabilitation because many ND injured patients demonstrated LSI <90%. There is a need for more research to confirm the results of this study, as well as consider other RTA metrics.