Restrictions in Ankle Dorsiflexion Range of Motion and its Effect on Landing Mechanics

Abstract

Bilateral landings are a common daily activity, yet the effect of restricted ankle dorsiflexion range of motion (DF ROM) on landing mechanics is not well established. The purpose of this thesis was to investigate the effects of ankle DF ROM restriction on bilateral drop-landing performance. In Chapter 3, the trigonometric calculation method for establishing tibia angle during the weight-bearing lunge test (WBLT) reliably measured ankle DF ROM for both single-limb and the between-limb differences. Chapter 4 provided reliability data for kinematic and kinetic measures of bilateral drop-landings from drop heights equal to 50%, 100% and 150% of a maximal countermovement jump (CMJ), which supported interpretation of the subsequent studies. Chapter 5 investigated the relationship between ankle DF ROM and bilateral drop-landing performance from three heights (50%, 100% and 150% CMJ). Although several moderate to large relationships were identified between ankle DF ROM and kinematic measures of landing mechanics, drop height did not moderate these correlations. Chapter 6 identified differences in measures of landing performance between individuals with functionally restricted and normal ankle DF ROM. The restricted group were unable to increase ankle dorsiflexion at peak flexion following a fatiguing task, relative to the normal group. However, between-group differences reported in this chapter may represent measurement error and demonstrated little functionally relevance. In the final data chapter, a 4-week combined mobility and strength-training intervention was found to improve WBLT performance more than a strength-training only intervention, resulting in greater ankle plantar flexion at initial contact, ankle dorsiflexion at peak flexion, and sagittal plane ankle joint displacement during bilateral drop-landings. Performing ankle mobility exercises, in combination with a strength-training, facilitated greater reliance on the ankle joint during landing tasks, while strength-training alone placed greater emphasis on the hip to attenuate landing forces.

Date of Award	21 Jul 2020
Original language	English
Awarding Institution	Edge Hill University
Supervisor	LARS MCNAUGHTON (Supervisor) & CRAIG BRIDGE (Supervisor)