1. Ground reaction forces and muscle activity while walking on sand versus stable ground in individuals with pronated feet compared with healthy controls
- Author
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Jafarnezhadgero, Amir Ali, Fatollahi, Amir, Amirzadeh, Nasrin, Siahkouhian, Marefat, and Granacher, Urs
- Subjects
Foot Deformities ,Male ,Muscle Physiology ,Physiology ,Science ,Knees ,Walking ,Research and Analysis Methods ,Strukturbereich Kognitionswissenschaften ,Pelvis ,Weight-Bearing ,Young Adult ,Sand ,Medicine and Health Sciences ,Humans ,Pronation ,Biomechanics ,ddc:610 ,Muscle, Skeletal ,Gait ,Musculoskeletal System ,Hip ,Electromyography ,Biological Locomotion ,Feet ,Muscles ,Electrophysiological Techniques ,Gastrocnemius Muscles ,Biology and Life Sciences ,Bioassays and Physiological Analysis ,Lower Extremity ,Body Limbs ,ddc:50 ,Medicine ,Legs ,Female ,ddc:500 ,Anatomy ,Musculoskeletal Mechanics ,Muscle Electrophysiology ,Research Article - Abstract
Background Sand is an easy-to-access, cost-free resource that can be used to treat pronated feet (PF). Therefore, the aims of this study were to contrast the effects of walking on stable ground versus walking on sand on ground reaction forces (GRFs) and electromyographic (EMG) activity of selected lower limb muscles in PF individuals compared with healthy controls. Methods Twenty-nine controls aged 22.2±2.5 years and 30 PF individuals aged 22.2±1.9 years were enrolled in this study. Participants walked at preferred speed and in randomized order over level ground and sand. A force plate was included in the walkway to collect GRFs. Muscle activities were recorded using EMG system. Results No statistically significant between-group differences were found in preferred walking speed when walking on stable ground (PF: 1.33±0.12 m/s; controls: 1.35±0.14 m/s; p = 0.575; d = 0.15) and sand (PF: 1.19±0.11 m/s; controls: 1.23±0.18 m/s; p = 0.416; d = 0.27). Irrespective of the group, walking on sand (1.21±0.15 m/s) resulted in significantly lower gait speed compared with stable ground walking (1.34±0.13 m/s) (p0.05; d = 0.06–1.60). We could not find any significant group by surface interactions for peak GRFs and their time to peak. Significant main effects of “surface” were detected for anterior-posterior impulse and peak positive free moment amplitude (p0.05; d = 0.00–0.53). Conclusions The observed lower velocities during walking on sand compared with stable ground were accompanied by lower peak positive free moments during the push-off phase and loading rates during the loading phase. Our findings of similar lower limb muscle activities during walking on sand compared with stable ground in PF together with lower free moment amplitudes, vertical loading rates, and lower walking velocities on sand may indicate more relative muscle activity on sand compared with stable ground. This needs to be verified in future studies., Postprints der Universität Potsdam : Humanwissenschaftliche Reihe, 590
- Published
- 2019