Abstract
Objective: Investigate the effect of surface on frontal plane knee angle, knee moment and muscle activity.
Design: Randomised cross over.
Setting: University Laboratory.
Methods: Twenty females performed single-leg hop-landings onto sand, grass and firm surfaces. Kinematic, kinetic and muscle activity data were obtained. Compatibility curves were used to visualise parameter estimates alongside P- values, and S-value transforms.
Results: Knee angle for firm-sand (mean difference (π)Μ = -2.2Β°; 95% compatibility interval (CI): -4.6 to 0.28, p =0.083, s = 3.6) and firm-grass (π Μ= -1.9; 95% CI: -4.3 to 0.5, p=0.125, S = 3) yielded < 4 bits of reputational information against the null hypothesis (H). 5 bits (p =0.025) of information against H were observed for knee moment between firm-sand (π Μ = 0.17 N.m/kg-1.m-1; 95% CI: 0.02 to 0.31) with similar effects for firm-grass (π Μ = 0.14 N.m/kg-1.m-1; 95% CI: -0.02 to 0.29, p =0.055, S = 4). Muscle activity across surfaces ranged from almost no (S=1) reputational evidence against H (Quadriceps and Hamstrings) to 10-13 βbitsβ against H for lateral gastrocnemius (lower on sand).
Conclusions: Our study provides valuable information for practitioners of the observed effect sizes for lower-limb landing mechanics across surfaces in asymptomatic females.
Keywords: sand, knee abduction moment, frontal plane, muscle activity.
Design: Randomised cross over.
Setting: University Laboratory.
Methods: Twenty females performed single-leg hop-landings onto sand, grass and firm surfaces. Kinematic, kinetic and muscle activity data were obtained. Compatibility curves were used to visualise parameter estimates alongside P- values, and S-value transforms.
Results: Knee angle for firm-sand (mean difference (π)Μ = -2.2Β°; 95% compatibility interval (CI): -4.6 to 0.28, p =0.083, s = 3.6) and firm-grass (π Μ= -1.9; 95% CI: -4.3 to 0.5, p=0.125, S = 3) yielded < 4 bits of reputational information against the null hypothesis (H). 5 bits (p =0.025) of information against H were observed for knee moment between firm-sand (π Μ = 0.17 N.m/kg-1.m-1; 95% CI: 0.02 to 0.31) with similar effects for firm-grass (π Μ = 0.14 N.m/kg-1.m-1; 95% CI: -0.02 to 0.29, p =0.055, S = 4). Muscle activity across surfaces ranged from almost no (S=1) reputational evidence against H (Quadriceps and Hamstrings) to 10-13 βbitsβ against H for lateral gastrocnemius (lower on sand).
Conclusions: Our study provides valuable information for practitioners of the observed effect sizes for lower-limb landing mechanics across surfaces in asymptomatic females.
Keywords: sand, knee abduction moment, frontal plane, muscle activity.
| Original language | English |
|---|---|
| Journal | Physical Therapy in Sport |
| DOIs | |
| Publication status | E-pub ahead of print - 11 Jul 2024 |