[OT 103] Lec 3: Kinematics and Kinetics of Walking

ANKLE: Initial contact

• Heel strike

• Neutral (0 degrees PF)

• Pre-tibial muscles decelerate forefoot lowering

• Draw tibia forward to prepare for initial contact.

• 1st period of double limb support

ANKLE: Loading response

• Foot flat

• PF (5 degrees)

• Pre-tibia muscles decelerate lower foot

• Draw tibia forward to prepare for initial contact

• 1st period of double limb support

ANKLE: Mid-stance

• Midstance

• DF (5 degrees)

• Plantarflexors increase activity

• Controlled progression of tibia

• Elastic energy stored in Achilles Tendon

• 1st period of single limb support

ANKLE: Terminal stance

• Heel off

• DF (10 degrees)

• Plantarflexors increase activity

• Controlled progression of tibia

• Elastic energy in Achilles Tendon

• 1st period of double limb support

ANKLE: Pre-swing

• Toe off

• PF (15 degrees)

• Calf muscles cease in early preswing

• Elastic energy from AT assists in rapid plantarflexion

• 2nd period of double limb support

ANKLE: Initial swing to mid-swing

• Acceleration / Midswing

• PF (5 degrees) to neutral

• Pre-tibial muscles elevate foot to neutral by midswing

• Posture is maintained

ANKLE: Mid-swing to terminal swing

• Midswing / Deceleration

• Neutral (0 degrees)

• Pre-tibial muscle elevate the foot by midswing

• Posture is maintained

KNEE: Initial contact

• Heel strike

• Fully extended

• Low amplitude hamstring activity = resist knee hyperextension

• 1st period of double limb support

KNEE: Loading response

• Foot flat

• Flexion (20 degrees)

• Eccentric vastii activity = knee extension

• For shock absorption = prevent collapse

• 1st period of double limb support

KNEE: Mid-stance

• Midstance

• Fully extended

• Vastii activity decreases by middle of midstance

• 1st period of single limb support

KNEE: Terminal stance

• Heel off

• Fully extended

• Vastii activity decreases by middle of midstance

• 2nd period of double limb support

KNEE: Pre-swing

• Toe off

• Flexion (40 degrees)

• Rectus femoris modulates rate of knee flexion

• 2nd period of double limb support

KNEE: Initial swing

• Acceleration

• Flexion (60 degrees)

• Biceps femoris (short head), gracilis, and sartorius = knee flexion (Adductors)

• 2nd period of single limb support

KNEE: Mid-swing

• Mid-swing

• Flexion (25 degrees)

• Hamstrings modulate rate of knee extension

• 2nd period of double limb support

KNEE: Terminal swing

• Deceleration

• Fully extended

• Hamstrings continue the activity

• Vastii activates for next double limb stance

HIP: Initial contact

• Heel strike

• Flexion (20 degrees)

• Single joint hip extensors contract = stabilize pelvis and trunk

• Hamstring activity is diminishing

• 1st period of double limb support

HIP: Loading response

• Foot flat

• Flexion (20 degrees)

• Single hip joint extensors contract = stabilize pelvis and trunk

• Hamstring activity is diminished

• 1st period of double limb support

HIP: Mid-stance

• Mid-stance

• Neutral

• Residual hamstring activity assists hip extension at the beginning

• Low-level adductor activity stabilizes the pelvis

• 1st period of single limb support

HIP: Terminal stance

• Heel off

• Hyperextension (20 degrees)

• Low amplitude tensor fascia latae activity

• 2nd period of double limb support

HIP: Pre-swing

• Toe off

• Hyperextension (10 degrees)

• Rectus femoris assists with early thigh advancement

• 2nd period of double limb support

HIP: Initial swing

• Acceleration

• Flexion (15 degrees)

• Iliacus, adductor longus, gracilis, and sartorius advance the thigh (Adductors)

• 2nd period of single limb support

HIP: Mid-swing

• Mid-swing

• Flexion (25 degrees)

• Increasing hamstring activity at the end

• Restrains further thigh advancement

• 2nd period of single limb support

HIP: Terminal swing

• Deceleration

• Flexion (20 degrees)

• Hamstrings control thigh posture

• Single joint hip extensors and abductors increase in activity for next phase