Relationship Between Clinical Musculoskeletal Measures And Heel Whip Gait Patterns In Recreational Runners

PURPOSE: Running-related musculoskeletal injuries (MSI) are common. Heel whip (HW), foot medial/lateral rotation in the transverse plane during the swing phase of running, is a relatively novel biomechanical variable; therefore, limited research examining its relationship to MSI exists. The aim of the study was to examine the relationship of HW with dorsiflexion (DF) range of motion (ROM), tibial torsion (TT), hip abduction strength, and postural control during a Single Leg Squat Test (SLST) performance in runners. Researchers theorized that reduced ankle DF ROM, increased TT, reduced hip abduction strength, and poorer SLST biomechanics would be correlated with increased HW. METHODS: Clinical measurements and treadmill (TM) running were obtained during a single, 30-minute session. DF ROM was measured with a lunge test using a digital inclinometer. TT was measured prone with a goniometer. Hip abduction strength was measured in side lying with a handheld dynamometer. For clinical measurements, three trials were collected and averaged for data analyses. SLST and TM running (self-selected pace, 0% incline for 3 minutes) were recorded using an iPhone camera from anterior and posterior views, respectively. Videos were imported into Coach’s Eye application, and pelvic drop and knee valgus during the SLST and HW during running were measured. Data were assessed for normality and Pearson-Product Moment correlations or Spearman-Rank correlations were used to determine the relationship between HW and each clinical measure. Statistical significance was set at p < 0.05, a priori. RESULTS: There was a significant moderate negative correlation between HW on the non-dominant leg (NDL) and DF on the DL (r = -0.517, p = 0.016). There was a significant moderate positive correlation between HW on the NDL and dynamic valgus collapse on the NDL during SLST (r = 0.641, p = 0.002). There was a significant low-to-moderate positive correlation between DL HW and NDL HW (r = 0.472, p = 0.031). CONCLUSIONS: DF ROM, hip ABD strength, and postural control deficits may contribute to biomechanical changes during the swing phase on the contralateral limb, affecting foot positioning at heel strike and toe-off. Future research should examine if HW is related to MSI risk and if modifying these characteristics reduces HW and MSI risk.