Gait Analysis and Swing Phase

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is primarily concerned with limb advancement during the swing phase?

Maintaining a rigid limb

Foot clearance from the floor (correct)

Preparation for stability at terminal contact

Knee flexion during initial contact

Which sub-phases constitute the first half of the swing phase?

Midswing and terminal swing

Terminal stance and initial contact

Initial swing and midswing (correct)

Initial swing and terminal swing

What does the term 'step length' refer to?

The average distance covered during a stride

The horizontal distance between two heels

The distance from one foot's heel initial contact to the other foot's heel contact (correct)

The distance between two successive contacts of the same foot

Which of the following statements about stride length is true?

It can vary significantly due to asymmetrical walking. Signup and view all the answers

What does kinematic analysis primarily study?

Variables related to motion such as positions and angles Signup and view all the answers

Which category is NOT part of kinematic analysis?

Kinetic forces Signup and view all the answers

What is the average step width for adults typically measured as?

2.5 to 12.5 cm Signup and view all the answers

During the terminal swing phase, what occurs to the knee?

It begins rapid extension to lengthen the limb. Signup and view all the answers

What is the primary role of the dampening effect during gait?

To maintain stability of the head. Signup and view all the answers

In which plane do the head, arms, and trunk (HAT) primarily displace during normal gait?

Sagittal plane. Signup and view all the answers

What is the maximum flexion angle of the shoulder at 50% of the gait cycle?

10º of flexion. Signup and view all the answers

How does the amplitude of shoulder movement change with walking speed?

It increases with greater speed. Signup and view all the answers

What is the typical angle of elbow flexion at heel contact?

20º. Signup and view all the answers

During which phase does the peak downward deviation occur?

Preswing. Signup and view all the answers

In kinetic analysis of gait, which of the following is an internal force?

Muscle activity. Signup and view all the answers

What is the relationship between shoulder and hip movement during the gait cycle?

They exhibit a consistent phase relationship. Signup and view all the answers

What is the primary role of the soleus and gastrocnemius during the terminal stance?

To control tibial advancement Signup and view all the answers

During the preswing phase, what is the primary action of the plantar flexors?

Reduce their intensity of action Signup and view all the answers

Which muscles are primarily responsible for maintaining lateral stability at the hip joint during early stance?

Gluteus medius and gluteus maximus Signup and view all the answers

What type of contraction do hip abductors undergo during the loading response?

Eccentric contraction to control pelvic drop Signup and view all the answers

What is the primary role of the tibialis anterior during the terminal swing?

To ensure a neutral ankle for heel contact Signup and view all the answers

What type of muscle contraction occurs in the hip abductors during midstance?

Concentric contraction for hip abduction Signup and view all the answers

During the initial contact, how does the ground reaction force vector (GRFV) affect the hip joint?

It generates an adduction moment that is counteracted by the adductor magnus Signup and view all the answers

What role do the tibialis anterior, extensor digitorum longus, and extensor hallucis longus play during initial swing and midswing?

To facilitate toe clearance Signup and view all the answers

What occurs in the hip joint during the preswing phase of gait?

The hip joint requires abduction due to activity of the adductor magnus. Signup and view all the answers

Which muscle group primarily counterbalances the adduction torque in the knee during the stance phase?

Biceps femoris and gluteus maximus Signup and view all the answers

In the presence of gluteus medius weakness, how does the pelvis respond during midstance?

The pelvis drops laterally toward the non-stance limb. Signup and view all the answers

What kind of gait pattern is associated with gluteus medius weakness?

Trendelenburg gait Signup and view all the answers

What is the role of the tibialis anterior, tibialis posterior, FHL, and soleus during the stance phase?

They counterbalance the eversion moment. Signup and view all the answers

How can an individual compensate for gluteus medius weakness during gait?

By leaning the trunk laterally toward the opposite side. Signup and view all the answers

How does the gravitational force vector (GRFV) affect the hip joint in the case of gluteus medius weakness?

It shifts medially, creating a strong adduction moment. Signup and view all the answers

What is the significance of the tension of ligaments at the knee in the frontal plane during gait?

It plays a crucial role in maintaining knee stability. Signup and view all the answers

What occurs to the pelvis when walking with an unequal leg length?

The pelvis tips downwards on the side of the shortened limb. Signup and view all the answers

Which gait abnormality is characterized by swinging the leg outward to avoid ground contact?

Circumduction Signup and view all the answers

What is the primary difference between anatomical and functional leg length discrepancies?

Functional discrepancies may not involve actual difference in leg length. Signup and view all the answers

Which phase requires the stance leg to be longer than the swing leg for natural walking?

Stance phase Signup and view all the answers

What condition might lead to a functional leg length discrepancy during the swing phase?

Spasticity of knee extensors Signup and view all the answers

Which of the following actions would functionally shorten the leg for the swing phase?

Flexing at the hip and knee Signup and view all the answers

What factor commonly causes an increase in leg length functional discrepancy following a stroke?

Tone increase in hip and knee extensor muscles Signup and view all the answers

Which condition will lead to a leg being too short for the stance phase?

Flexion contracture in a joint Signup and view all the answers

Study Notes

Swing Phase

The swing phase is concerned with limb advancement, which involves foot clearance and preparation for initial contact.
During initial swing and midswing, the limb flexes at the hip, knee, and ankle to shorten the limb for clearance.
In terminal swing, knee extension lengthens the limb, increasing step length and preparing for stability at initial contact.

Gait Analysis

Gait analysis classifies into kinematic and kinetic analysis.
Kinematics studies positions, angles, velocities, and accelerations of body segments and joints during motion.
Kinetic analysis studies the forces acting on the body during gait.

Kinematic Analysis

Distance and time variables are classified as spatial parameters.
Step length is the distance between initial contacts of opposite feet, averaging 64 cm for women, 73 cm for men, and 70.5 cm overall.
Stride length is the distance between successive foot contacts of the same limb, averaging 128 cm for women, 146 cm for men, and 141 cm overall.
Stride width is the horizontal distance between heel midpoints, typically 2.5 to 12.5 cm for adults, averaging 8 cm.

Head and Trunk During Gait

Head and trunk move as a unit, with deviations in all three planes.
Center of gravity (COG) displacement forms a sinusoidal curve, with upward deviations during midstance and late midswing, and downward deviations during loading response and preswing.

Shoulder Joint Motion During Gait

Shoulder exhibits a sinusoidal movement pattern opposite the hip, flexing when the hip extends and vice versa.
Shoulder reaches maximum extension at heel contact (25º) and maximum flexion at 50% of the gait cycle (10º).
Amplitude of shoulder movement increases with gait speed.
Arm swing balances rotational forces in the trunk and does not significantly affect energy expenditure during walking.

Elbow Joint Motion During Gait

Elbow is at 20º of flexion during heel contact.
It flexes to 45º during the first half of the gait cycle alongside shoulder flexion.
It returns to 20º of flexion in the second half of the gait cycle with shoulder extension.

Kinetic Analysis of Gait

Forces of gait include external forces (inertia, gravity, and ground reaction force) and internal forces (muscles, ligaments, tendons, joint capsules, and bony components).

Muscle Activity During Gait

Terminal stance: Soleus and gastrocnemius contract eccentrically to control tibial advancement, prevent excessive dorsiflexion, and decelerate the tibia.
Preswing: Plantar flexors contract concentrically to accelerate advancement of the unloaded limb.
Initial swing and midswing: Tibialis anterior, extensor digitorum longus, and extensor hallucis longus contract concentrically to dorsiflex the ankle and isometrically to maintain neutral position.
Terminal swing: Pretibial group muscles activate isometrically, with increasing activity of tibialis anterior to ensure neutral ankle positioning for heel contact.

Frontal Plane Analysis

Hip joint experiences demands for lateral stability during early stance. This is provided by gluteus medius, gluteus maximus, and tensor fascia lata.
Initial contact:
- Adductor magnus contracts concentrically to counterbalance abduction moment from the laterally positioned GRFV.
- Pelvis drops slightly.
Loading response:
- Gluteus medius, gluteus maximus, and tensor fascia lata contract eccentrically to control pelvic drop and counterbalance adduction moment.
Midstance and terminal stance:
- Hip abductors contract concentrically to counterbalance adduction moment and elevate the pelvis.
Preswing:
- Adductor magnus mainly contacts eccentrically to counterbalance abduction moment from the laterally positioned GRFV.
Knee joint: Biceps femoris and gluteus maximus tension on the iliotibial band stabilize the knee against adduction torque.
Subtalar joint:
- Lateral GRFV during loading response continues subtalar eversion, allowing foot adaptation.
- Inversion muscles (tibialis anterior, tibialis posterior, FHL, and soleus) contract eccentrically to counterbalance eversion moment.

Pathological Gait

Gluteus Medius Weakness:
- The pelvis drops laterally towards the opposite side during loading response and midstance due to inability of gluteus medius to counteract the adduction moment.
- This creates a Trendelenburg gait.
- Compensation involves leaning the trunk laterally towards the side of weakness.
Unequal Leg Length:
- Pelvis tilts downwards on the side of the shortened limb, creating a "stepping into a hole" appearance.
- The tilt is accompanied by compensatory lateral trunk bending.

Functional Leg Length Discrepancy

Four gait abnormalities (circumduction, hip hiking, steppage, and vaulting) aim to overcome functional discrepancies in leg length.
Functional discrepancy occurs when one or both legs cannot adjust to the appropriate length for a gait cycle phase.
Circumduction:
- A swinging leg that is functionally too long is swung outward in a circular motion to avoid ground contact.
- This usually occurs as a result of a neurological issue where a foot drop is accompanied by hip and knee extensor spasticity.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz explores the swing phase of gait, focusing on limb advancement and foot clearance, as well as the kinematic and kinetic aspects of gait analysis. Dive into the specifics of distance measurements like step and stride length to enhance your understanding of human locomotion.