Physiological effects of motor learning strategies to retrain running gait: A pilot study

Running gait retraining has been proposed as a rehabilitation strategy for overuse, running-related injuries (Barton et al., 2016, British Journal of Sports Medicine, 50, 513-526) and uses motor learning strategies to facilitate changes in running gait. Whilst risk-reducing effects in biomechanical indicators of overuse injury have been evidenced, the concurrent effects on physiological performance responses are unclear. The aim of the study was to develop an insight into the physiological effects of running gait retraining strategies commonly used in injury rehabilitation. With institutional ethics approval, nine recreational, rearfoot striking runners (mean ± SD age: 24 ± 5 years; height 1.70 ± 7.4m; body mass 68.3 ± 6.2kg) completed three conditions of treadmill running (six min) at 10 km.hr-1, with a five min rest period between conditions. A normal running condition and two intervention conditions using the verbal cues of “run quietly” (quiet) and “run like you are trying to squash oranges” (orange) were completed in a randomised order. The intervention conditions represented external focus of attention and analogy motor learning strategies respectively and involved cues being presented every 30s. Mean oxygen consumption and heart rate during the final two min and mean central (cRPE) and peripheral (pRPE) ratings of perceived exertion were obtained for the cohort during each condition. The orange condition produced the greatest increase in oxygen consumption (2.8%; effect size [ES] 0.51) and heart rate (3.3%; ES 0.53) compared to the normal condition. The quiet condition had similar oxygen consumption (-0.1%; ES 0.04) and heart rate (0.7%; ES 0.11) to the normal condition. Oxygen consumption and heart rate were greater in the orange condition than the quiet (2.9%; 0.81 ES and 2.7%; 0.91 ES, respectively). The orange and quiet conditions had slightly elevated pRPE compared to normal condition (11.4, 11.4 and 10.9 respectively), as well as an elevated cRPE (12.4, 12.0 and 11.6 respectively). An analogy learning strategy was found to have larger effects on physiological indicators of running performance during gait retraining than an external focus of attention, possibly due to underlying biomechanical alterations evidenced in the analogy learning strategy (Gittoes et al., 2017 BASES). The respective effects were reflected in perceived central effort levels and partially reflected in perceived peripheral muscular effort levels. Clinicians implementing running gait retraining to reduce biomechanical risk indicators are encouraged to use analogy cues, but to consider reducing running workload due to the physiological effects associated with this motor learning strategy