Methodological considerations of task and shoe wear on joint energetics during landing

Abstract

To better understand methodological factors that alter landings strategies, we compared sagittal plane joint energetics during the initial landing phase of drop jumps (DJ) vs. drop landings (DL), and when shod vs. barefoot. Surface electromyography, kinematic and kinetic data were obtained on 10 males and 10 females during five consecutive drop landings and five consecutive drop jumps (0.45m) when shod and when barefoot. Energy absorption was greater in the DJ vs. DL (P=.002), due to increased energy absorption at the hip during the DJ. Joint stiffness/impedance was more affected by shoe condition, where overall stiffness/impedance was greater in shod compared to barefoot conditions (P=.036). Further, hip impedance was greater in shod vs. barefoot for the DL only (via increased peak hip extensor moment in DL), while ankle stiffness was greater in the barefoot vs. shod condition for the DJ only (via decreased joint excursion and increased peak joint moment in DJ vs. DL) (P=.011). DJ and DL place different neuromechanical demands upon the lower extremities, and shoe wear may alter impact forces that modulate stiffness/impedance strategies. The impact of these methodological differences should be considered when comparing landing biomechanics across studies.

Peak Vertical Ground Reaction Force during Two-Leg Landing: A Systematic Review and Mathematical Modeling

“…The landing biomechanics is often affected by the landing type [1, 23], instruction [14], shoe [39], ankle stabilizer [16], surface stiffness [2], and participant's age [40], sex [41], fatigue [42], and vision [43]. In many cases, researchers tried to find some evidences in PvGRF to evaluate certain influential factors, but many conflicting conclusions have been obtained in these studies.…”

Multi-segment foot landing kinematics in subjects with chronic ankle instability

“…Both jumping conditions occurred barefooted so this could be considered when comparing and extrapolating study results given that shod versus barefoot landings may alter impact forces that modulate stiffness strategies [34]. Any possible difference in foot type between groups was not accounted for by means of e.g.…”

Timing differences in the generation of ground reaction forces between the initial and secondary landing phases of the drop vertical jump

“…Therefore, biomechanical differences between landings can be attributed to participant response rather than external influences such as changes in fall height. Neuromuscular and biomechanical differences were reported between the first and second landings of a DVJ as well as between the drop jump and drop landing tasks they mimic, respectively (Ambegaonkar et al, 2011; Bates et al, 2013b; Shultz et al, 2012). Decreased time to peak vGRF in the first landing, along with the statistically insignificant increase in RFD, may indicate that this landing phase exhibits mechanical behaviors that better represent joint loading that leads to injury than the second landing.…”

“…Thus, the first landing in a DVJ is a drop jump, whereas the second is a drop landing. Drop jumps and drop landings elicit different neuromechanical responses that dichotomize the tasks (Ambegaonkar et al, 2011; Shultz et al, 2012). Specifically, lower extremity muscles demonstrated greater peak activation magnitudes in drop jumps than drop landings, but time to peak activation remained equivalent between tasks.…”