Ankle dorsiflexion range of motion is associated with kinematic but not kinetic variables related to bilateral drop-landing performance at various drop heights

Abstract

25Limited evidence is available concerning ankle dorsiflexion range of motion (DF ROM) and 26 its relationship with landing performance from varying drop heights. The aim of this 27 investigation was to determine the relationship between ankle DF ROM and both kinetic and 28 kinematic variables measured during bilateral drop-landings from 50%, 100% and 150% of 29 countermovement jump height. Thirty-nine participants were measured for their ankle DF 30 ROM using the weight-bearing lunge test, after which five bilateral drop-landings were 31 performed from 50%, 100% and 150% of maximal countermovement jump height. 32Normalized peak vertical ground reaction force (vGRF), time to peak vGRF and loading rate 33 was calculated for analysis, alongside sagittal-plane initial contact angles, peak angles and 34 joint displacement for the hip, knee and ankle. Frontal-plane projection angles were also 35 calculated. Ankle DF ROM was not related to normalized peak vGRF, time to peak vGRF or 36 loading rate (P > 0.05), regardless of the drop height. However, at drop heights of 100% and 37 150% of countermovement jump height, there were numerous significant (P < 0.05) 38 moderate to large correlations between ankle DF ROM and initial contact angles (r = -0.34 -39 -0.40) and peak angles (r = -0.42 --0.52) for the knee and ankle joint. Knee joint 40 displacement (r = 0.39 -0.47) and frontal-plane projection angle (r = 0.37 -0.40) had a 41 positive relationship with ankle DF ROM, which was consistent across all drop heights. 42Ankle DF ROM influences coordination strategies that allow for the management of vGRF 43 during bilateral drop-landings, with alterations in alignment for the knee and ankle joints at 44 both initial contact and peak angles. 45 46 47 48 Highlights 49• Ankle dorsiflexion range of motion (DF ROM) does not influence landing forces. 50• Reduced ankle DF ROM alters coordination patterns during bilateral landings. 51• Strategies to compensate for ankle DF ROM restriction may increase injury risk.

Restrictions in Ankle Dorsiflexion Range of Motion Alter Landing Kinematics But Not Movement Strategy When Fatigued

“…12 Consistent with this suggestion, several studies have reported no relationship between ankle mobility and landing forces. [12][13][14] However, ankle DF ROM measured using the weight-bearing lunge test (WBLT), is related to ankle dorsiflexion (r = -0.31 to -0.34) and knee flexion (r = -0.37 to -0.41) angles at initial contact during bilateral drop-landings from drop heights equating to 100% and 150% of countermovement jump (CMJ) height in recreational athletes. 12 In the same investigation, significant relationships were also found between ankle DF ROM and peak ankle dorsiflexion (r = -0.43 to -0.44), knee flexion (r = -0.42 to -0.52) and frontal plane projections angles (FPPA) (r = 0.37) at the moment of peak knee flexion during bilateral drop-landings.…”

“…3 However, restrictions in ankle dorsiflexion range of motion (DF ROM) can negatively influence the coordination of the proximal segments during landings by imposing a mechanical organismic constraint that can limit an individual's capacity to adopt effective movement strategies. [11][12][13][14] It is therefore possible that reduced ankle DF ROM contributes to the development of compensatory strategies throughout the lower extremity in an attempt to maintain peak vGRF below an intolerable threshold. 12 Consistent with this suggestion, several studies have reported no relationship between ankle mobility and landing forces.…”

“…[11][12][13][14] It is therefore possible that reduced ankle DF ROM contributes to the development of compensatory strategies throughout the lower extremity in an attempt to maintain peak vGRF below an intolerable threshold. 12 Consistent with this suggestion, several studies have reported no relationship between ankle mobility and landing forces. [12][13][14] However, ankle DF ROM measured using the weight-bearing lunge test (WBLT), is related to ankle dorsiflexion (r = -0.31 to -0.34) and knee flexion (r = -0.37 to -0.41) angles at initial contact during bilateral drop-landings from drop heights equating to 100% and 150% of countermovement jump (CMJ) height in recreational athletes.…”

“…[12][13][14] However, ankle DF ROM measured using the weight-bearing lunge test (WBLT), is related to ankle dorsiflexion (r = -0.31 to -0.34) and knee flexion (r = -0.37 to -0.41) angles at initial contact during bilateral drop-landings from drop heights equating to 100% and 150% of countermovement jump (CMJ) height in recreational athletes. 12 In the same investigation, significant relationships were also found between ankle DF ROM and peak ankle dorsiflexion (r = -0.43 to -0.44), knee flexion (r = -0.42 to -0.52) and frontal plane projections angles (FPPA) (r = 0.37) at the moment of peak knee flexion during bilateral drop-landings. These findings suggest restrictions in ankle DF ROM cause a stiffer landing strategy through limiting knee flexion, necessitating compensations at initial ground contact and the moment of peak knee flexion to prevent excessive peak vGRF.…”

“…8 Interestingly, such compensations are similar to those demonstrated at initial contact by individuals with restrictions in ankle DF ROM. 12 It may be that when in a fatigued state, individuals with limited ankle DF ROM are unable to alter joint alignment at initial contact as a strategy to manage peak vGRF due to the mobility restriction already requiring this compensation.…”