Understanding Gait Phases in Human Motion

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Questions and Answers

What occurs during the falling phase when the center of mass (COM) moves forwards beyond the forefoot?

The catching phase automatically begins.

The COM stabilizes without any need for movement.

The body remains in a stable position.

The body experiences a balance upset requiring a step. (correct)

During the catching phase, what type of support is the body in?

Unilateral support phase

Triangular support phase

Single support phase

Double support phase (correct)

To regain balance after the COM is upset, what must the body do first?

Remain stationary to regain composure.

Move backwards outside the base of support.

Shift weight to the opposite leg.

Take a step forwards outside the base of support. (correct)

What is the primary focus during the pre-swing phase?

Preparing for the next phase of motion. Signup and view all the answers

What action is necessary when the COM is in a state of double support?

To catch the COM. Signup and view all the answers

What happens to the knee extensors during the flexing phase when gravity is acting?

They contract eccentrically Signup and view all the answers

When the heel touches down and the ankle is in a neutral position, what is required for full contact with the floor?

Plantar flexion Signup and view all the answers

Which muscle is primarily responsible for resisting gravity's tendency to cause plantar flexion?

Tibialis anterior Signup and view all the answers

What action do the dorsiflexors take when gravity attempts to cause plantar flexion?

They lengthen eccentrically Signup and view all the answers

What role does pronation play when gravity is acting on the foot?

It is encouraged by gravity Signup and view all the answers

Which muscles contract eccentrically to facilitate the supination of the foot?

Tibialis posterior Signup and view all the answers

During the mid-stance phase of walking, what is the primary function of this stage?

Absorb forces then propel the body Signup and view all the answers

How do the muscles that supinate the foot respond under the influence of gravity?

They contract eccentrically Signup and view all the answers

What occurs during the loading phase when transitioning from double to single support?

The rear leg is accepting body weight. Signup and view all the answers

Which statement accurately describes the mid-stance phase?

It occurs entirely on a single support leg. Signup and view all the answers

What is a key characteristic of the loading phase regarding body weight transfer?

The body's center of mass travels forward. Signup and view all the answers

In the mid-stance phase, what role does the opposite leg play?

It is never in contact with the ground. Signup and view all the answers

Which of the following best describes the impacts of the loading phase on the front leg?

It becomes steady to absorb energy. Signup and view all the answers

How does the single support phase contribute to movement?

It enables the body's center of mass to travel forward. Signup and view all the answers

What happens to the rear leg during the transition to single support?

It begins to accept the body's weight. Signup and view all the answers

What is the primary function of the steady front leg during the loading phase?

To absorb the energy of impacts. Signup and view all the answers

What happens to the trunk during the stance phase of using a knee prosthetic?

It leans towards the amputated side. Signup and view all the answers

In which plane is lateral trunk bending observed while using a prosthetic?

Frontal plane. Signup and view all the answers

What may cause weakness in the abductors when using a knee prosthetic?

Improper socket fitting. Signup and view all the answers

What is essential for effective swing during locomotion?

Ensuring proper hip flexions and knee extensions Signup and view all the answers

What effect does a poorly fitted prosthetic socket have on gait?

It causes discomfort and pain. Signup and view all the answers

What is a common observation during gait analysis with a long knee prosthetic?

Decreased lateral stability. Signup and view all the answers

What does MFC stand for in the context of locomotion?

Minimum Foot Clearance Signup and view all the answers

Which phase primarily reflects the stance phase of gait analysis?

Stance phase. Signup and view all the answers

During which phase does initial contact (IC) occur?

Terminal stance Signup and view all the answers

What can be a direct consequence of inadequate proprioception in amputees using prosthetics?

Increased risk of falls. Signup and view all the answers

Why is foot clearance important in gait?

To reduce the risk of tripping Signup and view all the answers

What might indicate issues with a knee prosthetic's fit?

Frequent slipping or pinching. Signup and view all the answers

What characterizes the early swing (ESW) phase?

High foot position above the ground Signup and view all the answers

Which of the following occurs during mid-swing (MSW)?

Foot clearance maximization Signup and view all the answers

What is the primary focus of terminal stance (TSW)?

Controlling the balance during weight transfer Signup and view all the answers

What happens to the leg during the hip flexion phase?

The leg swings forward Signup and view all the answers

Which of the following best describes the importance of the swing phase?

It is crucial for foot clearance and effective locomotion Signup and view all the answers

What is a key characteristic of effective swing mechanics?

Consistent clearance of the foot above the ground Signup and view all the answers

What prevents falling during the swing phase?

Proper coordination of hip and knee actions Signup and view all the answers

Which joint movement is primarily involved in the swing phase?

Hip flexion Signup and view all the answers

What effect does insufficient foot clearance have on gait?

Increases the risk of stumbling or tripping Signup and view all the answers

What follows toe-off in the gait cycle?

Mid-swing phase Signup and view all the answers

What is meant by 'freezing' in the context of gait patterns?

A problem of pacing caused by environmental changes. Signup and view all the answers

What is a common characteristic of Parkinsonian gait during the OFF phase?

Shuffling gait with reduced arm swing. Signup and view all the answers

How can individuals overcome freezing during gait?

By listening to another rhythm, such as a metronome. Signup and view all the answers

What does an ON phase in Parkinsonian gait typically indicate?

Enhanced movement with unimpeded flow. Signup and view all the answers

Which of the following describes the shuffling gait observed in Parkinsonian patients?

A gait characterized by small steps and little arm swing. Signup and view all the answers

What can trigger freezing when approaching doorways?

A sudden change in direction. Signup and view all the answers

Which scenario describes an OFF phase accurately?

The individual displays minimal arm movement while walking. Signup and view all the answers

What could potentially enhance movement during the ON phase?

Administering medication to ease symptoms. Signup and view all the answers

Study Notes

Gait

Gait is a series of intentional falls with the goal of taking the center of mass (COM) outside the base of support (BOS) and catching yourself with a step.
It involves a swing phase (40%) and a stance phase (60%).
Gait is a double to single support transition.

Gait Phases

Loading (LOAD): Initial Contact (IC) → Opposite Toe Off (OTO)
Mid-Stance (MST): Opposite Toe Off (OTO) → Heel Rise (HR)
Terminal Stance (TST): Heel Rise (HR) → Opposite Initial Contact (OIC)
Pre-Swing (PSW): Opposite Initial Contact (OIC) → Toe Off (TO)

Loading Phase

Movement from double to single support
Transferring body weight from rear leg to front leg
Front leg becomes steady to absorb impact and weight.

Mid-Stance Phase

Longest phase
Single support
Opposite leg never touches the ground
Goal: Allow COM to travel over the fixed foot while maintaining single support
Preparing for the next fall opportunity

Terminal Stance Phase

Falling phase and start of catching phase
COM moves forward (beyond the forefoot)
Need to take a step to regain balance
Transition to single support.
Catch COM when it's over the BOS

Pre-Swing Phase

Getting ready for swing phase
Progressively unload the right limb while loading the left
Bringing weight from right to left
Preparing to transition into single support

Swing Phase

Preparing to catch the fall.
Swinging limb to make progress forward
Accepting body weight and moving forward/
Dual pendulum motion through hip flexion & knee extension
Minimum Foot Clearance (MFC)
Effective swing to avoid falling

Phases of Swing

Early Swing (ESW)
Mid Swing (MSW)
Terminal Swing (TSW)

Temporal-Spatial Parameters

Step Length: Varies depending on walking speed
Walking Base (Step Width): 10-15 cm, variable; wider in obese individuals
Stride Length: Anterior to posterior difference of one foot; average value = 1.4m; sum of right and left steps
Toe Angle: Tip of 2nd toe and centre of heel; average value = 5-10° (thinking about line of progression)
Comfortable Adult Walking Speed: variable, 1.2-1.4 m/s, 4.5-5 km/hour

Foot Drop Gait

Damage to the peroneal nerve that feeds the dorsiflexors
Foot drop gait
Increased hip flexion to help the leg pass through
Foot placed on the ground in a flat position
Heel rolls into toe during loading

Steppage Gait

Lack of dorsiflexion (DF)
Bilateral deficits
Toes drag through swing phase
No clearance of the ground
Foot hangs in plantarflexion (PF) position

Vaulting

Stiff knee and hip
Can't get enough hip/knee flexion
Limb is functionally long
Can't activate hamstrings (during swing phase)
Exaggerated vertical motion
Ask the opposite leg to plantarflex (PF) for vertical lift (higher COM) to provide space for the swinging limb to pass through.

Trendelenburg

Neurological pathology at the superior gluteal nerve feeds the adductors
Osteoarthritic hip
Other conditions (patellofemoral syndrome)
Weakness of hip abductors
Pelvic tilt towards opposite side of supporting leg
Lateral shift of COM toward stance leg during mid-stance
Compensation: Trunk shifts COM closer to hip joint, abductors don’t have to work as hard

Hemiplegia/Hemiparesis

Less severe state, weakness but not paralysis
Influences posture
Affects how the person moves
CNS pathology (stroke, cerebral palsy, TBI)
Upper extremity: flexion dominates, hypertonic, arm held close to body.
Lower extremity: extension, functionally long leg, foot in PF.

Parkinsonian Gait

Loss of dopamine causing degenerative disease
Tremors, shaking
Stiff movements
Involuntary muscle contractions
Balance and gait difficult
Stooped, shuffling
Limited extremity motion, especially lower extremities.
Limited arm swing during gait
Freezing: sudden stop in movement
Change in gait pattern that disrupts rhythm (e.g. doors, obstacles)
Overcome by other rhythm (e.g. metronome)
Off phase: shuffling gait, limited movement, small arm swing.
On phase (with medication): Improved movement and arm swing

GRF/Ground Reaction Forces

Reaction to the body weight and muscular effort during balancing, walking, and jumping.
Higher than body weight
Changes during stance phase
Comes through center of pressure (COP) to center of mass (COM) constantly changing
Orientation changes through stance phase and is usually higher during the stance phase

Impact Transient

Brief initial spike in ground reaction force (GRF) as the foot makes impact.
Does not impact muscle response
Think of GRF as an elastic band, what happens when it passes each joint?
Recruit muscles that oppose gravity to counter it.
Some joints are neutral

Orthotics

Insoles that help with foot positioning.
Determining Factors: Pain, Function (training/activities), Alignment, Biomechanics
Orthotic assessment: history, biomechanics, postural analysis, functional tests (squats, lunges, balance, calf raises), gait and run analysis

Prosthetics

Artificial limbs for individuals with limb loss
Main causes of amputation: diabetes, peripheral vascular disease
Lower limb amputations: Hemipelvectomy, hip disarticulation, above-knee amputation, knee disarticulation, below-knee amputation, ankle disarticulation, partial foot.
Assessment: objective (strength, characteristics), subjective (goals, lifestyle).
Gait analysis (focus on one plane/distal to proximal), compare to normal or sound limb.

Gait deviations in transfemoral amputee

Circumduction
Vaulting
Lateral Trunk Bending

Gaitway Neurophysiology (PD)

Basal Ganglia: Motor circuits, habitual/goal directed movements, associative circuits (executive function, attention), Limbic circuits (motivation, reward)
Dopamine = Neurotransmitter, crucial for voluntary movement and smooth execution, also assists with dual/multitasking and cognitive function.
Substantia nigra (biggest factor) is the source of dopamine.

Neuroprotective Exercise for PD

High Intensity, Challenging and Amplitude is important for exercise.
Big movements,
Flowing (rigidity/shuffling/stride length)
Active holds
Power movements to gets powerstance and balance
Specific exercises such as: boom whackers, using chairs for balance, high-energy, using rings.

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Description

This quiz explores the intricate phases of human gait, including the loading, mid-stance, and terminal stance phases. Test your knowledge on the mechanics of walking, the transition from double to single support, and the significance of each phase in maintaining balance and mobility.