Immediate Recovery

What stage of amputation recovery occurs approximately 2–6 months post-op?

Intermediate recovery stage.

What major residual limb change occurs during intermediate recovery?

Rapid residual limb volume reduction/change.

When is the initial prosthesis typically received?

Around 3 months after amputation.

When is a definitive prosthesis typically fabricated?

Around 9–12 months after amputation once limb volume and prosthetic mobility stabilize.

What is prosthetics?

The practice of fabricating and fitting artificial limbs.

What is a prosthetist?

A master's-level practitioner specializing in fabrication and fitting of prostheses.

What are the main goals during intermediate recovery?

Manage limb volume/healing, protect skin, teach prosthetic management, continue exercise, and begin prosthetic gait training.

What should be worn when the patient is NOT wearing the prosthesis during intermediate recovery?

The residual limb shrinker.

What factors cause residual limb volume changes >2 months post-op?

Muscle atrophy, prosthetic fitting, disease processes, weight changes, and continued healing.

How does wearing a prosthesis help decrease residual limb volume?

Weight bearing plus compression from the liner, sleeve, and socket create positive pressure.

What phase of healing is the residual limb scar typically in during intermediate recovery?

Remodeling phase.

Why is scar mobilization important before/during prosthetic use?

Prevents the scar from becoming bound down within the socket.

How common are skin problems in prosthetic users?

Approximately 36–66%.

What skin problems can occur with prosthetic liners?

Redness, skin breakdown, rash, and dermatitis.

How should a patient inspect areas of the residual limb they cannot see?

Use a handheld mirror or assistance from a caregiver/family member.

What exercises continue during intermediate recovery?

Strengthening, stretching, balance, and rhythmic stabilization.

How does exercise progress after receiving the prosthesis?

Exercises are progressed into prosthetic standing and functional activities.

What major new rehabilitation activity begins during intermediate recovery?

Prosthetic gait training.

Where is the normal COM in quiet standing with equal bilateral weight bearing?

Approximately anterior to S2.

How can unilateral amputation affect COM?

COM shifts toward the intact limb and may shift superiorly into the trunk.

Why must COM be retrained after a patient receives a prosthesis?

The patient has adapted to loading the intact limb and must relearn weight acceptance on the prosthetic side.

What is the center of mass (COM)?

The theoretical point where the body's mass is evenly distributed.

Can the COM lie outside the physical body?

Yes; its location changes with body position.

What is the base of support (BOS)?

The area created by the body parts contacting the supporting surface.

What happens to BOS when stance width increases?

BOS increases.

What happens to BOS when using an assistive device?

BOS increases.

What happens to BOS during single-limb stance?

BOS decreases.

What is the center of pressure (COP)?

The average location of pressures over the surface contacting the ground.

Where can the COP move?

Within the base of support.

How does COP normally progress through the foot during gait?

Heel → whole foot → metatarsal heads → great toe.

Approximately what percentage of walking gait is stance?

60%.

Approximately what percentage of walking gait is swing?

40%.

What are the stance phases in order?

Initial contact → loading response → midstance → terminal stance → pre-swing.

What are the swing phases in order?

Initial swing → midswing → terminal swing.

What occurs during initial double-limb support?

Both feet contact the ground at the beginning of stance.

What occurs during terminal double-limb support?

Both feet contact the ground again during pre-swing.

Approximately how much of the gait cycle is single-limb support?

40%.

Approximately how much of the gait cycle is double-limb support?

20% total.

What are the four rockers of gait in order?

Heel rocker → ankle rocker → forefoot rocker → toe rocker.

Which rocker occurs during initial contact/loading response?

Heel rocker.

Which rocker dominates from late loading response through midstance?

Ankle rocker.

Which rocker occurs during terminal stance?

Forefoot rocker.

Which rocker occurs during pre-swing?

Toe rocker.

Where does the forefoot rocker occur?

At the metatarsal heads.

Where does the toe rocker primarily occur?

At the great toe/first metatarsal region.

What causes progression from the ankle rocker to forefoot rocker?

Plantar flexors reach their elongation limit, controlling tibial advancement as the heel rises.

What functional advantage does the forefoot rocker provide?

Creates a functionally longer limb.

What hip motion is necessary to achieve normal terminal stance?

Hip extension.

How does a hip flexion contracture affect the gait rockers?

Limits terminal stance, preventing effective forefoot and toe rocker use.

How does loss of the forefoot/toe rocker affect the opposite limb?

Causes shorter contralateral step length.

A patient has a hip flexion contracture and takes a short step with the sound limb. Why?

Limited hip extension prevents terminal stance and forefoot/toe rocker progression on the prosthetic side.

A new prosthetic user takes short steps with the sound limb despite adequate ROM. What should the PT assess?

Whether the patient is progressing over the prosthetic forefoot and toe rockers.

What is the ground reaction force (GRF)?

The equal and opposite force the ground applies to the body during ground contact.

During which portion of gait does GRF exist?

Stance only.

Why is there no GRF during swing?

The foot is not contacting the ground.

Where does the GRF originate?

At the center of pressure.

Toward what point is the GRF directed?

Toward the center of mass.

What is the key GRF relationship to memorize?

COP → GRF → COM.

What types of GRF exist?

Vertical and horizontal/shear forces.

Why are shear forces clinically important in an insensate foot?

They can contribute to tissue damage and skin breakdown.

What does GRF create when it passes on one side of a joint axis?

An external joint moment.

What counters an external GRF moment?

An opposing internal muscular moment.

What knee moment occurs when GRF passes anterior to the knee?

External knee extension moment.

What knee moment occurs when GRF passes posterior to the knee?

External knee flexion moment.

Where does GRF pass relative to the knee during loading response?

Posterior to the knee.

What external knee moment occurs during loading response?

Knee flexion moment.

What muscle group normally controls the external knee flexion moment during loading response?

Quadriceps through an internal knee extension moment.

Why can a posterior GRF at the knee cause buckling?

It creates an external knee flexion moment that must be controlled.

Why is knee buckling especially important in a transfemoral amputee?

The patient relies on a prosthetic knee rather than an anatomical knee for stability.

A transfemoral patient's prosthetic knee repeatedly buckles during loading response. What GRF problem may be occurring?

GRF may be passing too far posterior to the prosthetic knee.

What should the PT do if repeated knee buckling appears related to prosthetic alignment?

Communicate with the prosthetist for assessment/adjustment.

Why might a new transfemoral prosthesis be aligned so GRF passes more anterior to the knee?

To increase the external extension moment and improve knee stability.

How can repeated prosthetic knee buckling affect the patient psychologically/functionally?

Decreases trust and confidence in the prosthesis and may limit walking.

Where does GRF pass in the frontal plane during loading response?

Medial to the knee and hip.

What external frontal-plane moment does a medially positioned GRF create?

An external adduction moment.

What knee motion couples with excessive ankle dorsiflexion?

Knee flexion.

What ankle motion couples with excessive knee flexion?

Dorsiflexion.

What knee motion couples with excessive ankle plantarflexion?

Knee extension.

What is the quick memory rule for ankle-knee coupling?

DF = knee bends; PF = knee straightens.

What lower-extremity pattern accompanies excessive hip flexion in stance?

Hip flexion → knee flexion → ankle dorsiflexion.

Why is a hip flexion contracture especially concerning in a transfemoral amputee?

It promotes knee flexion and can increase prosthetic knee instability/buckling risk.

A prosthetic ankle is positioned in excessive dorsiflexion. What knee position would you expect?

Excessive knee flexion.

A prosthetic ankle is positioned in excessive plantarflexion. What knee position would you expect?

Excessive knee extension.

A patient stands with excessive knee extension and bends the trunk forward. Why?

Forward trunk/hip flexion shifts COM forward to help maintain balance.

Why must shoe heel height be considered when aligning a prosthesis?

The prosthetic ankle may not accommodate heel-height changes, altering ankle position and knee mechanics.

What can a heel that is too high do to prosthetic alignment?

Increase dorsiflexion → increase knee flexion/buckling tendency.

What can a very low/flat heel do to prosthetic alignment?

Increase plantarflexion → increase knee extension and make knee flexion harder.

Why does the prosthetist ask patients to bring their usual shoes to fitting?

The prosthesis is aligned for the heel height they regularly wear.

A patient switches from their usual shoe to a much higher heel and begins feeling knee instability. Why?

Higher heel can increase prosthetic dorsiflexion → knee flexion → buckling tendency.

Why is GRF a primary concern during prosthetic alignment?

Its position relative to joints determines external moments, stability, and gait deviations.

What are the basic components of a transtibial prosthesis?

Socket → pylon → foot.

What are the basic components of a transfemoral prosthesis?

Socket → knee joint → pylon → foot.

What is the major component difference between TTA and TFA prostheses?

A transfemoral prosthesis includes a prosthetic knee joint.

What is the socket?

The hard proximal component that contains the residual limb.

What material are modern prosthetic sockets commonly made from?

Carbon fiber.

What is the pylon?

The structural component connecting the proximal prosthesis to the foot.

What does the K-level system describe?

The patient's functional ambulation potential and corresponding prosthetic needs.

What does K0 indicate?

No ability/potential to ambulate or transfer safely with a prosthesis; prosthesis does not enhance function.

What does K1 indicate?

Ability/potential for transfers or level-surface ambulation at a fixed cadence; household ambulator.

What does K2 indicate?

Ability/potential to traverse low-level environmental barriers; limited community ambulator.