Longitudinal Changes in Running Gait Asymmetries and Their Relationship to Personal Record Race Times in Collegiate Cross Country Runners

Abstract

Minimizing between-limb asymmetries during running is often a goal of training, as increased asymmetries are related to decreased efficiency and increased energy expenditure. However, it is unknown if asymmetries change with increased running exposure or are related to actual race performance. The purpose of this study was to determine (1) if pre-season asymmetries changed year-to-year among collegiate cross country runners, and (2) if these asymmetries were associated with within-season personal records (PRs). Pre-season biomechanical test results and race performance data were analyzed for 54 unique runners (28 female) across six seasons, totaling 152 assessments (age: 19.1 (0.9) years, height: 1.71 (0.10) m, weight: 61.7 (7.7) kg (values = mean [standard deviation])). Biomechanical asymmetries included ground reaction forces; ground contact time; base of gait; foot inclination angle; and peak hip flexion, hip extension, hip adduction, pelvic drop, knee flexion, and ankle dorsiflexion. Year of collegiate eligibility was used to quantify training exposure. Asymmetries during running did not change across years of eligibility (p ≥ 0.12), except propulsive impulse, which decreased over time (p = 0.03). PR times were faster with decreased propulsive impulse asymmetry and increased AVLR and peak ankle dorsiflexion asymmetries. This is the first study to assess longitudinal asymmetries over time and provide potential targets for interventions aimed at modifying asymmetries to improve performance.

Association between inter-limb asymmetry and endurance running performance in healthy populations: A systematic review

“…In novice runners, a lower asymmetry of time peak vertical ground reaction force was associated with increasing running velocity, whilst asymmetry in vertical load rate did not differ across velocities [51]. As opposed to average loading rate and braking impulse asymmetry (β = 0.00, p = 0.99), propulsive impulse asymmetry (β = 14.60, p < 0.01) was positively associated with within-season personal records on distances of 8 km for male runners and 6 km for female runners [49]. Controlled for sex, for every 5% increase in propulsive impulse asymmetry, personal records times within the running season increased by 16 seconds [49].…”

“…Previous research showed that peak ankle dorsi exion (i.e., maximal ankle dorsi exion angle during stance phase) later in stance was positively related to running economy and thus possibly affecting running performance [73]. In the study by Sti er-Joachim et al [49], inter-limb asymmetry in peak ankle dorsi exion was the only kinematic variable that was signi cantly and negatively correlated with within-season personal records (β = -6.1, CI: [-12.9, 0.7]. Every 1° increase in peak ankle dorsi exion asymmetry was related to a 7.6 s decrease in the best running time on 8km for male and 6 km for female distance runners.…”

“…In addition to the majority of research being performed in Europe (37.5%; GBR, ITA, POL) [35,45,46] and North America (37.5%; USA) [47][48][49], only one included study was conducted in South America (12.5%; BRA) [50] and another single study in China (12.5%; CHN) [51]. Furthermore, and except from one study being published in 2013 [45], all studies were published from 2018 on.…”

“…The mean age of study participants ranged between 17.1 years [35] and 42.6 years [45]. Across studies, these participants consisted for 68% of competitive runners (54% female) [35,45,46,48,49,51], 22% of recreational runners (36% female) [45,47,50,51] and 10% of novice runners (33% female) [45,51].…”

“…displacements in body centre of mass) and kinetic (e.g., ground reaction force, leg stiffness, braking impulse) variables were all collected while running [47][48][49][50][51] or during the execution of a CMJ [46].…”