The effect of reduced ankle dorsiflexion on lower extremity mechanics during landing: A systematic review.

OBJECTIVES: To examine the evidence for effect of restricted ankle dorsiflexion range of motion on lower-extremity landing mechanics. DESIGN: Literature review. METHODS: Systematic search of the literature. Articles critiqued by two reviewers. RESULTS: Six studies were identified that investigated the effect of restricted DF ROM on landing mechanics. Overall, results suggest that landing mechanics are altered with restricted DF ROM, but studies disagree as to the particular mechanical variables affected. CONCLUSIONS: There is evidence that restricted dorsiflexion range of motion may alter lower-extremity landing mechanics in a manner, which predisposes athletes to injury. Interpretation of results was made difficult by the variation in landing tasks investigated and the lack studies investigating sport-specific landing tasks. The focus of studies on specific mechanical variables rather than mechanical patterns and the analysis of pooled data in the presence of different compensation strategies between participants also made interpretation difficult. These areas require further research.

The effect of ankle bracing on lower extremity biomechanics during landing: A systematic review.

OBJECTIVES: To examine the evidence for effect of ankle bracing on lower-extremity landing biomechanics. DESIGN: Literature review. METHODS: Systematic search of the literature on EBSCO health databases. Articles critiqued by two reviewers. RESULTS: Ten studies were identified which investigated the effect of ankle bracing on landing biomechanics. Overall results suggest that landing biomechanics are altered with some brace types but studies disagree as to the particular variables affected. CONCLUSIONS: There is evidence that ankle bracing may alter lower-extremity landing biomechanics in a manner which predisposes athletes to injury. The focus of studies on specific biomechanical variables rather than biomechanical patterns, analysis of pooled data means in the presence of differing landing styles between participants, variation in landing-tasks investigated in different studies, and lack of studies investigating goal-directed sport-specific landing tasks creates difficulty in interpreting results. These areas require further research.

The Influence of Optimal Handheld Load on the Technical Ability to Apply Ground Reaction Forces during Horizontal Jumping in Female Netball Players.

Handheld load has been reported to enhance horizontal jump performance, however little is known about its influence on ground reaction forces (GRF), especially in female athletes. This study investigated the effects of individualized optimal handheld loading on the technical and physical ability to apply GRF during horizontal jumping in female netball players. Maximal effort, single standing, horizontal jumps were performed by 13 female netballers. Participants performed the jumps under 2 conditions: 1) unloaded, and 2) loaded. Eccentric mean horizontal GRF significantly increased with loading (p<0.05; Effect Size [ES]= 0.74). The ratio of horizontal-to-total GRF significantly increased (p<0.05; ES=0.57), however resultant GRF did not, suggesting that the technical ability to apply force in the direction of intended movement may be of greater importance than the magnitude of force applied. Jump distance also increased from 188.2±16.1 cm to 196.4±13.6 cm (p<0.01; ES=0.55) with handheld load. In conclusion, individualized optimal handheld loading improved single horizontal jump performance in this population of athletes; most likely through various mechanisms that allowed for increased eccentric horizontal GRFs and the technical ability of force application. Findings could have practical implications for the strength and conditioning coach, trainer and athlete.