Muscle actions in Gait

• Hip flexors:

  • whilst the hip is in extension at the end of stance phase Hip flexors work in an outer range to pull the hip into flexion
  • Hip flexors are most active right at the beginning of swing phase and as we get halfway into swing phase the activity of hip flexors reduce until they're completely inactive during the end part of swing phase
  • towards the end of swing phase the hip flexors switch off and let momentum do the work

  
• Hip flexors summary:

  • outer range
  • concentric contraction
  • rapidly produced contraction
  • to accelerate leg forward and generate momentum
  • to rehabilitate hip flexors: high reps as gait is repetitive, in outer range
• Hip adductors:

  • hip adductors are active at the start of swing phase, and are synergistic with hip flexors, so can compensate for hip flexors in abnormalities by laterally rotating the hip

  
• Gluteus Medius & Gluteus Minimus / Hip abductors:

  • are active throughout the whole of stance phase, whenever the leg is weightbearing the hip abductors are working
  • key role of hip abductors is to stabilise the pelvis during gait, so abductors contract to prevent non weightbearing side from dropping - if abductors are too weak to do this, it creates a Trendelenburg gait pattern
  • concentric and eccentric contractions take place but quite minimally

  
• Gluteus maximus / Hip extensors:

  • are active at the very beginning of stance phase
  • switch off from mid stance and are only active again at the next heel contact at the beginning of stance phase again
  • hip flexors dont work during the continued extension in stance phase as the rapidly contracted to allow momentum to do the work
  • hip flexors are working: concentrically to produce a rapid movement, through mid range, at a very high load and then switch off to let momentum do the rest of the work

  
• Hamstrings:

  • are active at the very beginning of stance phase during initial heel contact when the hip is extending and the knee is flexing but dont play as much as a role as gravity does a lot of the work
  • also active at the end of swing phase to help with deceleration of swing phase to ensure correct foot placement, where the hamstrings are working eccentrically

  
• Quadriceps:

  • active at the beginning at stance phase when the knee is slightly flexed in inner range to aid with weightbearing, so the quadriceps produce an eccentric contraction and as the knee starts to extend it becomes a concentric contraction in inner range
  • active a bit at the end of stance phase during push off, stopping the knee from hyperflexing

  
• Plantarflexors:

  • weak plantarflexors cause a weak/inability to push off at the end of stance phase

  
• Dorsiflexors:

  • active at the beginning of stance phase from initial heel contact to when the foot is on the ground, the dorsiflexors work eccentrically at a very high load to control the lowering of the foot onto the ground
  • active during swing phase at a low load, initially working concentrically and then isometrically to keep the toes off the ground