Ankle-dorsiflexion Range of Motion and Landing Biomechanics

J Athl Train. Jan-Feb 2011;46(1):5-10. doi: 10.4085/1062-6050-46.1.5.

Abstract

Context: A smaller amount of ankle-dorsiflexion displacement during landing is associated with less knee-flexion displacement and greater ground reaction forces, and greater ground reaction forces are associated with greater knee-valgus displacement. Additionally, restricted dorsiflexion range of motion (ROM) is associated with greater knee-valgus displacement during landing and squatting tasks. Because large ground reaction forces and valgus displacement and limited knee-flexion displacement during landing are anterior cruciate ligament (ACL) injury risk factors, dorsiflexion ROM restrictions may be associated with a greater risk of ACL injury. However, it is unclear whether clinical measures of dorsiflexion ROM are associated with landing biomechanics.

Objective: To evaluate relationships between dorsiflexion ROM and landing biomechanics.

Design: Descriptive laboratory study.

Setting: Research laboratory.

Patients or other participants: Thirty-five healthy, physically active volunteers.

Intervention(s): Passive dorsiflexion ROM was assessed under extended-knee and flexed-knee conditions. Landing biomechanics were assessed via an optical motion-capture system interfaced with a force plate.

Main outcome measure(s): Dorsiflexion ROM was measured in degrees using goniometry. Knee-flexion and knee-valgus displacements and vertical and posterior ground reaction forces were calculated during the landing task. Simple correlations were used to evaluate relationships between dorsiflexion ROM and each biomechanical variable.

Results: Significant correlations were noted between extended-knee dorsiflexion ROM and knee-flexion displacement (r = 0.464, P = .029) and vertical (r = -0.411, P = .014) and posterior (r = -0.412, P = .014) ground reaction forces. All correlations for flexed-knee dorsiflexion ROM and knee-valgus displacement were nonsignificant.

Conclusions: Greater dorsiflexion ROM was associated with greater knee-flexion displacement and smaller ground reaction forces during landing, thus inducing a landing posture consistent with reduced ACL injury risk and limiting the forces the lower extremity must absorb. These findings suggest that clinical techniques to increase plantar-flexor extensibility and dorsiflexion ROM may be important additions to ACL injury-prevention programs.

MeSH terms

  • Ankle / physiology
  • Ankle Joint / physiology*
  • Anterior Cruciate Ligament Injuries
  • Anterior Cruciate Ligament* / anatomy & histology
  • Anterior Cruciate Ligament* / physiology
  • Biomechanical Phenomena
  • Female
  • Humans
  • Knee / physiology*
  • Knee Injuries / physiopathology
  • Knee Joint / physiology
  • Male
  • Motor Activity
  • Movement
  • Musculoskeletal Physiological Phenomena
  • Posture / physiology
  • Range of Motion, Articular*
  • Young Adult