1. Gait Cycle: Initial Contact

fucking kill me.

What phase of the gait cycle is Initial Contact part of?

Double limb support.

What rocker begins at Initial Contact?

Heel rocker.

What phase is the contralateral limb in during Initial Contact?

Terminal Stance.

In the sagittal plane, what is the pelvic tilt during Initial Contact?

Anterior pelvic tilt 15°

In the sagittal plane, what is the hip angle during Initial Contact?

25° of flexion

In the sagittal plane, where is the GRF relative to the hip joint during Initial Contact?

Anterior to the hip joint.

In the sagittal plane, what external moment occurs at the hip during Initial Contact?

External hip flexion moment.

In the sagittal plane, what internal moment counters the hip flexion moment during Initial Contact?

Internal hip extension moment.

In the sagittal plane, what muscles are active at the hip during Initial Contact, and how do they contract?

Glute max and hamstrings; concentrically

In the sagittal plane, what is the knee angle during Initial Contact?

0° (full extension).

In the sagittal plane, where is the GRF relative to the knee during Initial Contact?

Anterior to the knee joint.

In the sagittal plane, what external moment occurs at the knee during Initial Contact?

External extension moment.

In the sagittal plane, what internal moment counters the knee extension moment during Initial Contact?

Internal knee flexion moment (to control knee position).

In the sagittal plane, what muscles are active at the knee during Initial Contact, and how do they contract?

Vasti muscles; eccentrically.

In the sagittal plane, what is the ankle position during Initial Contact?

0° (neutral).

In the sagittal plane, where is the GRF relative to the ankle during Initial Contact?

Posterior to the ankle joint.

In the sagittal plane, what external moment occurs at the ankle during Initial Contact?

External plantarflexion moment.

In the sagittal plane, what internal moment counters the ankle plantarflexion moment during Initial Contact?

Internal dorsiflexion moment.

In the sagittal plane, what muscles are active at the ankle during Initial Contact, and how do they contract?

Pretibials (Tibialis Anterior, EDL, EHL, Fibularis Tertius); eccentrically.

In the sagittal plane, what is the MTP joint position during Initial Contact?

15° extension.

In the frontal plane, where is the GRF relative to the hip during Initial Contact?

Medial to the hip joint

In the frontal plane, what external moment occurs at the hip during Initial Contact?

External adduction moment

In the frontal plane, what muscles counter the hip adduction moment during Initial Contact, and how do they contract?

Hip abductors (e.g., glute med); eccentrically.

In the frontal plane, where is the GRF relative to the subtalar joint during Initial Contact?

Lateral to the subtalar joint

In the frontal plane, what external moment occurs at the subtalar joint during Initial Contact?

Pronation + (subtalar) eversion

In the frontal plane, what muscles counter the eversion moment at the subtalar joint during Initial Contact, and how do they contract?

Tibialis Anterior and Posterior; eccentrically

In the horizontal plane, what pelvic movement occurs during Initial Contact?

Forward rotation (3–5° max)

In the horizontal plane, what rotation occurs at the hip during Initial Contact?

Slight external rotation (~5° max)

In the horizontal plane, what is the knee rotation during Initial Contact?

Slight external rotation

What is the hip position and moment chain at IC (sagittal plane)?

25° Flexion
GRF anterior → Hip Flexion → Hip Extension (hamstrings + glute max), CONCENTRIC

What is the hip position and moment chain at IC (sagittal plane)?

25° flexion.
GRF anterior → Hip flexion → Hip extension (hamstrings + glute max), CON.

What is the knee position and moment chain at IC (sagittal plane)?

0°.
GRF anterior → Knee extension → Vasti ECC to control flexion + prevent collapse.

What is the ankle position and moment chain at IC (sagittal plane)?

0°.
GRF posterior → PF → DF (pretibials: Tib Ant., EDL, EHL, Fib Tertius), ECC to control PF.

What is the MTP joint position at Initial Contact (sagittal plane)?

15° extension.

What is the frontal plane moment chain at the hip during IC?

GRF medial to hip → Hip adduction → Hip abductors ECC

What is the frontal plane moment chain at the foot/subtalar joint during IC?

GRF lateral to heel → Subtalar eversion/pronation → Tib Ant + Tib Post ECC.

What is the pelvic rotation at IC (horizontal plane)?

Forward rotation, 3–5° max.

What is the hip rotation at IC (horizontal plane)?

ER 5° max.

What is the knee rotation at IC (horizontal plane)?

Slight ER.