DEFINING LIMB DOMINANCE: A COMPARISON OF PERFORMANCE-BASED AND SELF-SELECTED MEASURES

BACKGROUND: Limb dominance implies asymmetrical performance due to preferential strength or motor control within a single limb. While dominance may be easy to define and quantify within the upper extremity, there is currently no consensus as to whether limb dominance exists within the lower limbs, and if it does, how to best define it. While objective differences in limb performance would be the gold-standard for the identification of limb dominance, these methods may not be feasible within injured athletes. Several methods of identifying perceived limb dominance utilizing subjective reporting have been described; however, limb dominance may be task dependent and reports analyzing the correlation between objective and subjective performance are limited, particularly among adolescent athletes. PURPOSE: The purpose of this study was to test the agreement between performance-based and self-reported measures of limb dominance in three different single leg hopping tasks. METHODS: These data were prospectively collected as part of a large cross-sectional study of healthy youth athletes aged 8-16 years-old. Self-selected limb dominance was determined by asking the following question: “Which leg would you use to kick a ball as far as you could?”. Each subject performed a series of single leg hops and 3-trial means of the single hop for distance (SH), timed hop (TH), and vertical hop (VH) were used for analysis. Paired samples t-test or Wilcoxon-Signed Rank test were utilized to identify differences in limb performance for each of the hop tests. Associations between self-selected and performance-based measures of limb dominance were analyzed using Chi-square. RESULTS: A total of 352 subjects (55% male(n=191), mean age=11.1) were included. There was a small but statistically significant difference in side-to-side performance for all hop tests with a mean difference of 2.58cm(p<0.001) for SH, 0.13s(p<0.001) for TH and 0.29cm(p=0.03) for VH. There was limited agreement between self-selected and performance-based limb dominance across all hop tests (55%SH, 54%VH, and 66%TH). Similarly, Chi-square analysis revealed no associations (p>0.05) between self-selected and performance-based limb dominance across all hop test constructs. CONCLUSIONS: Although a single limb did perform better on all hop tests, the mean differences were small, and likely not clinically relevant. Perceived limb dominance did not predict performance regardless of hopping task. These findings illustrate that equality of performance can be considered normal for young athletes recovering from lower extremity injury. This information also brings into question the appropriateness of holding the perceived dominant limb to higher standards or accepting lower standards for the non-dominant limb. TABLES AND FIGURES: REFERENCES: 1. Goekeler A, Welling W, Benjaminse A. A critical analysis of limb symmetry indices of hop tests in athletes after anterior cruciate ligament reconstruction: a case control study. Orthop Traumatol Surg Res. 2017;103(6):947-951. doi: 10.1016/j.otsr.2017.02.015. 2. Losciale JM, Zdeb RM, Ledbetter L, Reiman MP, Sell TC. The Association Between Passing Return-to-Sport Criteria and Second Anterior Cruciate Ligament Injury Risk: A Systematic Review With Meta-analysis. Journal of Orthopaedic & Sports Physical Therapy. 2019;49(2):43-54. doi:10.2519/jospt.2019.8190. 3. Mulrey CR, Shultz SJ, Ford KR, Nguyen A-D, Taylor JB. Methods of Identifying Limb Dominance in Adolescent Female Basketball Players. Clinical Journal of Sport Medicine. 2018;Publish Ahead of Print. doi:10.1097/jsm.0000000000000589; 4. van Melick N, Meddeler BM, Hoogeboom TJ, Maria W. G. Nijhuis-Van Der Sanden, Cingel REHV. How to determine leg dominance: The agreement between self-reported and observed performance in healthy adults. Plos One. 2017;12(12). doi:10.1371/journal.pone.0189876. 5. Velotta, J. & Weyer, J. & Ramirez, A. & Winstead, J. & Bahamonde, Rafael. Relationship between leg dominance tests and type of task. Portugese J Sport Sci. 2011;11(1035-1038). 6. Wellsandt E, Failla MJ, Snyder-Mackler L. Limb symmetry indexes can overestimate knee function after anterior cruciate ligament injury. J Orthop Sports Phys Ther. 2017;47(5):334-338.