PT 815 Lecture 2: Gait Analysis - Joint Moments and Muscle Contractions

What are joint moments

- Measure of a forces tendency to cause rotation about a joint axis

o External: GRF

o Internal: produced by tissue to counter GRF

Initial contact GRF relative to the hip, knee and ankle

- Anterior to hip

- Anterior to knee

- Posterior to ankle

Initial contact external vs internal moment at the hip

- External: hip flexion

- Internal: hip extension

Initial contact external vs internal moment at the knee

- External: knee extension

- Internal: knee flexion

Initial contact external vs internal moment at the ankle

- External: plantarflexion

- Internal: dorsiflexion

Loading response GRF relative to the hip, knee and ankle

- Anterior to hip

- Posterior to knee

- Posterior to ankle

Loading response external vs internal moment at the hip

- External: hip flexion

- Internal: hip extension moment

What muscle contraction happens during loading response at the hip

- Concentric glute max and hamstrings

Loading response external vs internal moment at the knee

- External: knee flexion

- Internal: knee extension

What muscle contraction happens during loading response at the knee

- Eccentric quads

Loading response external vs internal moment at the ankle

- External: ankle plantar flexion

- Internal: ankle dorsiflexion

What muscle contraction happens during loading response at the ankle

- Eccentric tibialis anterior

Midstance GRF relative to the hip, knee and ankle (sagittal plane)

- Posterior to hip

- Anterior to knee

- Anterior to ankle

Midstance external vs internal moment at the hip (sagittal plane)

- External: hip extension

- Internal: hip flexion

What muscle contraction happens during midstance at the hip (sagittal plane)

- Eccentric iliopsoas

Midstance external vs internal moment at the knee (sagittal plane)

- External: knee extension

- Internal: knee flexion

What muscle contraction happens during midstance at the knee (sagittal plane)

- Eccentric hamstrings

Midstance external vs internal moment at the ankle (sagittal plane)

- External: ankle dorsiflexion

- Internal: ankle plantarflexion

What muscle contraction happens during midstance at the ankle (sagittal plane)

- Eccentric gastroc and soleus

Midstance GRF relative to the hip, knee and ankle (frontal plane)

- Medial to hip

- Medial to knee

- Lateral ankle

Midstance external vs internal moment at the hip (frontal plane)

- External: hip adduction

- Internal: hip abduction

What muscle contraction happens during midstance at the hip (frontal plane)

- Eccentric glute Medius

Midstance external vs internal moment at the knee (frontal plane)

- External: knee adduction

- Internal: knee abduction

What muscle contraction happens during midstance at the knee (frontal plane)

- NONE bahahah, Ligaments

Midstance external vs internal moment at the ankle (frontal plane)

- External: Ankle eversion

- Internal: ankle inversion

What muscle contraction happens during midstance at the ankle (frontal plane)

- Eccentric tibalis posterior

Terminal stance GRF relative to the hip, knee and ankle

- Posterior to hip

- Anterior to knee

- Anterior to ankle

Terminal stance external vs internal moment at the hip

- External: hip extension

- Internal: hip flexion

What muscle contraction happens during terminal stance at the hip

- Eccentric quads and iliopsoas

Terminal stance external vs internal moment at the knee

- External: knee extension

- Internal: knee flexion

What muscle contraction happens during terminal stance at the knee

- Eccentric hamstrings

Terminal stance external vs internal moment at the ankle

- External: ankle dorsiflexion

- Internal: ankle plantarflexion

What muscle contraction happens during terminal stance at the ankle

- Eccentric gastroc and soleus

Preswing GRF relative to the hip, knee and ankle

- Posterior to hip

- Posterior to knee

- Anterior to ankle

Preswing external vs internal moment at the hip

- External: hip extension

- Internal: hip flexion

What muscle contraction happens during pre-swing at the hip

- Concentric iliopsoas

Preswing external vs internal moment at the knee

- External: knee flexion

- Internal: knee extension

What muscle contraction happens during pre-swing at the knee

- Eccentric quads

Preswing external vs internal moment at the ankle

- External: dorsiflexion

- Internal: plantarflexion

What muscle contraction happens during pre-swing at the ankle

- Concentric gastroc and soleus