2.6 Gait, Assistive Devices, Weight-Bearing Status
Key Takeaways
- Weight-bearing statuses: non-weight-bearing (NWB) — 0%; toe-touch weight-bearing (TTWB) — toe touches floor for balance only, ~10-15% body weight; partial weight-bearing (PWB) — 30-50%; weight-bearing as tolerated (WBAT) — patient-limited; full weight-bearing (FWB) — 100%.
- Axillary crutch fit: crutch tip 2 inches lateral and 6 inches anterior to the shoe, with the axillary pad 2-3 fingerbreadths (~5 cm) below the axilla and elbow flexed 20-30 degrees; weight is borne on the hands, never the axilla.
- A single-point cane is held in the hand OPPOSITE the affected lower extremity; the cane and the affected leg advance together to reduce hip abductor demand.
- Walker height is set so the top of the walker reaches the patient's wrist crease when arms hang at the sides, producing 20-30 degrees of elbow flexion when grasped.
- The Rancho Los Amigos gait cycle divides stance into initial contact, loading response, midstance, terminal stance, and pre-swing, and swing into initial swing, midswing, and terminal swing.
Weight-Bearing Statuses
The surgeon or physical therapist (PT) sets the weight-bearing status; the PTA implements it and collects data on the patient's adherence. Standard categories used across U.S. PT practice:
| Status | Abbreviation | Percent Body Weight | Practical Description |
|---|---|---|---|
| Non-weight-bearing | NWB | 0% | Surgical limb cannot touch the floor |
| Toe-touch weight-bearing | TTWB / TDWB | ~10-15% | Toe rests on floor for balance only |
| Partial weight-bearing | PWB | 30-50% (often specified, e.g., 50%) | Specific percentage applied through the limb |
| Weight-bearing as tolerated | WBAT | Variable | Patient bears as much weight as is comfortable |
| Full weight-bearing | FWB | 100% | No restriction |
A bathroom scale at parallel bars is one PTA-friendly way to teach a patient what the assigned percent feels like before ambulation.
Assistive Device Fitting
Axillary Crutches
- Crutch tip placed about 2 inches lateral and 6 inches anterior to the shoe.
- Axillary pad 2-3 fingerbreadths (~5 cm / 2 inches) below the axilla.
- Hand grip set so the elbow is in 20-30 degrees of flexion.
- Weight is borne through the hands, never the axilla — sustained axillary pressure can compress the radial nerve and brachial plexus.
Forearm (Lofstrand) Crutches
- Cuff sits 1-1.5 inches below the olecranon.
- Hand grip set so the elbow is in 20-30 degrees of flexion.
- Useful for patients with adequate upper-extremity strength who need long-term mobility aids.
Cane (Single-Point or Quad)
- Held in the hand opposite the affected lower extremity.
- Cane height equals the distance from the floor to the wrist crease (ulnar styloid level) with the arm relaxed; elbow flexed 20-30 degrees when grasped.
- The cane and affected leg advance together to share load and reduce hip abductor demand (decreases joint reaction force at the affected hip).
Walker
- Top of the walker reaches the wrist crease with arms relaxed.
- Elbow flexion 20-30 degrees when grasping.
- Standard walker advanced first, then the affected leg, then the stronger leg.
- A rolling walker is appropriate when the patient cannot safely lift and advance a standard walker.
Common Gait Patterns
| Pattern | When Used |
|---|---|
| Two-point | One crutch/cane and opposite leg advance together; mild bilateral involvement |
| Three-point | Both crutches and affected leg advance; uninvolved leg follows; NWB or PWB |
| Modified three-point | Like three-point but the affected leg bears partial weight; PWB or WBAT |
| Four-point | Reciprocal — right crutch, left leg, left crutch, right leg; most stable, bilateral involvement |
| Swing-to / Swing-through | Both crutches advance, then both legs swing to or past the crutches; spinal cord injury, bilateral LE weakness |
Rancho Los Amigos Gait Cycle
The modern terminology used on the NPTE-PTA divides one cycle into eight phases:
Stance (~60%):
- Initial contact (heel strike)
- Loading response (foot flat)
- Midstance
- Terminal stance (heel off)
- Pre-swing (toe off)
Swing (~40%):
- Initial swing (acceleration)
- Midswing
- Terminal swing (deceleration)
Double-limb support occurs twice per cycle (at loading response and at pre-swing) and disappears at faster speeds (running).
Common Gait Deviations a PTA Documents
| Deviation | Common Cause |
|---|---|
| Trendelenburg gait (pelvic drop on swing-leg side) | Weak hip abductors (gluteus medius) on the stance side |
| Antalgic gait (shortened stance time on painful side) | Pain in the loaded limb |
| Foot drop / steppage gait | Weak dorsiflexors, often peroneal nerve or L4-L5 involvement |
| Circumduction | Functional leg-length discrepancy, weak hip flexors, or knee that cannot flex |
| Hyperextension of knee in midstance | Quadriceps weakness, plantarflexion contracture |
| Forward trunk lean in stance | Quadriceps weakness, hip flexor contracture, anterior knee pain |
A PTA describing a Trendelenburg sign during gait training collects the data and reports it; the supervising PT decides whether to alter the plan of care.
A PTA is fitting axillary crutches for a patient with a right ankle fracture (toe-touch weight-bearing). Which fitting finding requires correction BEFORE gait training begins?
A patient with left hip osteoarthritis arrives walking with a single-point cane in the LEFT hand. The PTA notes a pelvic drop on the right during left-stance phase. What is the MOST appropriate PTA action within the plan of care?