BIOMECHANICS, GAIT, AND POSTURE

What is the purpose of evaluating movement?

To guide injury prevention, selection of rehabilitation techniques, and assessment of activity limitations.

What are the two main principles of biomechanics?

Kinematics (joint angles and movement) and kinetics (forces and Newton's laws).

What is torque in biomechanics?

Torque = Force x Moment arm, and it is important to consider when maximizing torque is beneficial or detrimental.

What are the three types of lever systems in biomechanics?

1st Class (fulcrum between effort and resistance), 2nd Class (effort proximal, resistance middle, fulcrum distal), 3rd Class (fulcrum proximal, effort middle, resistance distal).

1st class lever

fulcrum in between effort and resistance (see-saw) (head and neck)

2nd class lever

effort proximal, resistance middle, fulcrum distal (wheelbarrow) (ankle)

3rd class lever

fulcrum proximal, effort middle, resistance distal (shovel) (elbow)

length tension relationship

longest length too weak (actin can't bind to myosin) shortest length too week (sarcomeres overlap cant cycle cross bridges) optimal length for strength is in the middle

What is ideal posture aligned with?

Gravitational force, at equilibrium, resulting in less muscular effort and low stress on joints.

closed chain

standing, arms leaning on something

open kinetic hcain

seated legs not touching ground, arms out in open

What is assessed when evaluating posture?

Strength and flexibility of key muscle groups, NWB alignment, joint angles, and spinal curvature.

What characterizes kypholordotic posture?

Exaggerated curvatures at thoracic and lumbar spines with anterior pelvic tilt and knee joint hyperextension.

What is the definition of gait?

The manner of walking, characterized by base of support, center of gravity, step length, stride length, and other parameters.

What are the phases of gait according to Ranchos Los Amigos?

Heel Strike, Loading Response, Midstance, Terminal Stance, Toe-Off, Initial Swing, Midswing, Terminal Swing.

What is the goal of the Weight Acceptance phase in gait?

To achieve shock absorption and stability as the foot makes contact with the ground.

What occurs during the Single-limb support phase of gait?

The body maintains stability and progresses forward while one limb supports the weight.

What is the purpose of the Swing limb advancement phase?

To clear the foot from the ground and advance the limb forward.

What are the key components of self-optimization in walking?

Minimizing movement of the center of mass through pelvic rotation and knee flexion.

What distinguishes running from walking?

Running includes a flight phase, longer stride length, and greater hip and knee flexion.

What is the role of the hip during early support in sprinting?

Eccentric flexion followed by concentric extension.

What happens to the knee during midflight in sprinting?

The knee transitions from eccentric to concentric extension.

What is the significance of the plumb line in assessing posture?

It helps determine alignment of body segments in relation to gravitational forces.

What is the effect of muscle tightness on posture?

It can lead to compensatory strategies and imbalances, affecting overall alignment.

What is the difference between closed and open kinetic chains?

Closed kinetic chains involve fixed distal segments, while open kinetic chains involve free-moving distal segments.

What is normal spinal curvature?

A balanced curvature that includes lordosis in the lumbar region and kyphosis in the thoracic region.

What is the impact of forward head posture?

It results from weakened cervical flexors and tight cervical extensors.

What does the term 'cadence' refer to in gait analysis?

The number of steps taken per minute during walking or running.

What is the role of the ankle during the loading response phase?

Eccentric control of dorsiflexors to allow foot flat on the ground.

What is the significance of stride frequency?

It is a measure of how quickly a person walks or runs, impacting overall gait efficiency.

What is the role of the quadriceps during the initial contact phase?

They work eccentrically to control knee extension and absorb shock.

goals of initial contact

heel strikes first

goals of loading response

absorbing shock force, get foot flat on ground

goals of midstance

Balance, carry momentum

goals of terminal stance

spring loaded! body progressing forward

goal of pre-swing

spring releases! heal off to toe off; rapid knee flexion

goals of initial swing

hip and knee flexion to help foot clear the ground

goals of mid swing

foot clears ground; thigh continues to advance

goals of terminal swing

control step length, absorb load