Gait variability and symmetry remain consistent during high-intensity 10,000 m treadmill running

Abstract

The aim of this study was to analyze changes in gait variability and symmetry in distance runners. Fourteen competitive athletes ran on an instrumented treadmill for 10,000 m at speeds equivalent to 103% of their season's best time. Spatiotemporal and ground reaction force data were recorded at 1500, 3000, 5000, 7500 and 9500 m. Gait variability and inter-leg symmetry were measured using median absolute deviation (MAD) and the symmetry angle, respectively. There were no overall changes during the running bout for absolute values, symmetry angles or variability, and there were only moderate changes in variability between successive testing distances for three variables. Even with these few changes, variability was low (<4%) at all distances for all variables measured and, on average, the athletes were symmetrical for five of the seven gait variables measured. There were greater mean asymmetry values for flight time (1.1-1.4%) and for impact force (2.0-2.9%), which might have occurred because of muscle latency as the lower limb responded passively to impact during initial contact. Although most athletes were asymmetrical (>1.2%) for at least one variable, no one was asymmetrical for more than four of the seven variables measured. Being asymmetrical in a few variables is therefore not abnormal and not indicative of asymmetrical gait and given many practitioners analyze symmetry (and variability) on an individual, case-study basis, caution should be taken when assessing the need for corrective interventions.

The Influence of Exercise-Induced Fatigue on Inter-Limb Asymmetries: a Systematic Review

“…The studies used different designs. A differentiation can be made between studies regarding inter-limb asymmetries during a loading protocol [20,21,[30][31][32][33][34] (Table 3) and studies regarding inter-limb asymmetries with a supplementary task in a pre-post design [7,16,[35][36][37][38] (Table 4). In six studies, the subjects were tested for asymmetries at different points of time during the loading protocol [20,21,[31][32][33][34].…”

“…A differentiation can be made between studies regarding inter-limb asymmetries during a loading protocol [20,21,[30][31][32][33][34] (Table 3) and studies regarding inter-limb asymmetries with a supplementary task in a pre-post design [7,16,[35][36][37][38] (Table 4). In six studies, the subjects were tested for asymmetries at different points of time during the loading protocol [20,21,[31][32][33][34]. One study interspersed the loading protocol with several single-leg countermovement jumps (SLCMJ) to test asymmetries [30], and six studies used other tasks/procedures, such as jumps, isokinetic strength testing or a gait analysis, to test the subjects before and after the loading protocol [7,16,[35][36][37][38].…”

“…All thirteen studies used different types of physical load: five studies used a running protocol (three on a treadmill [20,31,35], one on a running track [30] and one used a soccer-specific running protocol modified with a kicking task [37]), one study used a race walking protocol on a treadmill [34], one study conducted an onwater field test in rowing [33], two studies tested asymmetries before and after soccer matches [16,38], two studies used the repetition of exercise as loading protocol (squatting [32], jumping [21]), and two studies used a combination of different exercises [7,36]. The loading protocols had different durations, and different methods were used to determine the end of the protocol: one study [7] used the ratings of perceived exertion (RPE) scale by BORG [39], two studies ended their loading protocol when the exercise or a certain output could no longer be maintained [21,36], in two cases the loading protocol was executed until volitional exhaustion [32,35], and in seven studies the subjects had to complete the prescribed protocol [16,20,30,31,33,34,37,38]. Moreover, exercise-induced fatigue was inferred based on four methods: four studies [7,31,35,37] used the RPE scale [39], another calculated a fatigue index [30], Girard et al [20] calculated a sprint decrement score, and others operationalized fatigue as the decrease of lower limb muscle power [21] or the point when an exercise could no longer be maintained [36].…”

“…In total, 252 people were examined (173 males and 79 females). Six studies included only male subjects (n = 97) [16,20,30,31,36,38], six both sexes (76 males, 65 females) [7,21,[32][33][34][35], and one only considered females (n = 14) [37]. The number of subjects in a study ranged from ten (five males, five females) [20] to 40 (20 males, 20 females) [7].…”

“…The number of subjects in a study ranged from ten (five males, five females) [20] to 40 (20 males, 20 females) [7]. Most of the subjects had a sporting background: in five studies, they were recreationally or physically active (n = 108) [7,20,30,32,36], one tested active runners (n = 14) [31], one included elite race walkers (n = 10) [34]; three studies focused on soccer players (n = 46) [16,37,38], one on university soccer players (n = 14) [37] and two on elite soccer players (n = 32) [16,38]; one study included elite skiers (n = 22) [21]; and one was on high-performance junior rowers (n = 32) [33]. Radzak et al [35] tested healthy and injury free athletes (n = 20), but did not mention their sporting background.…”