8.4 Gait Cycle Analysis & Pathological Gait Patterns
Key Takeaways
- Gait is the first named sub-topic of the 11% Functional Assessment content area on the NBCE Physiotherapy Test Plan.
- One gait cycle is roughly 60% stance and 40% swing, with two double-support periods of about 10% each that disappear in running.
- An antalgic gait shortens stance time on the painful limb; a Trendelenburg gait drops the contralateral pelvis from gluteus medius weakness.
- Steppage gait with a foot slap indicates dorsiflexor weakness, most often from a common fibular nerve lesion or an L4-L5 radiculopathy.
- Normal adult free-walking cadence is approximately 100 to 120 steps per minute, and reduced cadence with a widened base is a reliable early marker of balance impairment.
8.4 Gait Cycle Analysis & Pathological Gait Patterns
Core Clinical Mandate: "Gait" is the first named sub-topic of the Functional Assessment (11%) content area. Gait analysis is high-yield because a single observed deviation localizes a lesion: a dropping contralateral pelvis means gluteus medius, a slapping foot means dorsiflexors, a shortened stance phase means pain. The examination rewards linking observation → responsible muscle or nerve → intervention.
Structure of the Gait Cycle
One gait cycle (one stride) runs from initial contact of one foot to the next initial contact of the same foot.
| Division | Share of Cycle | Definition |
|---|---|---|
| Stance phase | ~60% | The reference limb is in contact with the ground |
| Swing phase | ~40% | The reference limb is airborne and advancing |
| Double support | ~10% × 2 = ~20% | Both feet contact the ground; occurs twice per cycle |
| Single support | ~40% | Only the reference limb is loaded |
The Running Distinction: Walking always has a period of double support. Running is defined by the loss of double support and the appearance of a float (flight) phase in which neither foot is in contact. As speed increases, stance time shortens and swing time lengthens.
Rancho Los Amigos Terminology
The Rancho Los Amigos system divides the cycle into eight functional sub-phases and is the vocabulary used in most modern texts.
Stance (weight acceptance, then single-limb support, then limb advancement begins):
- Initial contact — the instant the foot touches down (heel strike in normal gait).
- Loading response — from contact to contralateral toe-off; shock absorption.
- Mid-stance — from contralateral toe-off to when the body's centre of mass passes over the supporting foot.
- Terminal stance — from heel rise to contralateral initial contact.
- Pre-swing — from contralateral initial contact to ipsilateral toe-off; the push-off burst.
Swing:
- Initial swing — toe-off to maximum knee flexion.
- Mid-swing — the tibia reaches vertical.
- Terminal swing — from vertical tibia to the next initial contact; deceleration.
Joint Kinematics and Muscle Control
| Sub-Phase | Hip | Knee | Ankle | Key Muscle Action |
|---|---|---|---|---|
| Initial contact | ~30° flexion | ~0–5° flexion | Neutral | Dorsiflexors hold neutral; hamstrings decelerate |
| Loading response | Extending | Flexes to ~15–20° | Plantarflexes to ~10° | Dorsiflexors contract eccentrically to lower the forefoot; quadriceps eccentric for shock absorption |
| Mid-stance | Neutral | Extending toward 5° | Dorsiflexes to ~10° | Gluteus medius holds the pelvis level; soleus controls tibial advance eccentrically |
| Terminal stance | ~10–20° extension | Near extension | Peak dorsiflexion | Plantarflexors build tension; heel rises |
| Pre-swing | Extension reversing | Flexes to ~40° | Plantarflexes to ~20° | Gastrocnemius-soleus concentric push-off |
| Initial swing | Flexing | Peak flexion ~60° | Dorsiflexing | Hip flexors concentric; dorsiflexors clear the toes |
| Mid-swing | ~30° flexion | Extending | Neutral | Dorsiflexors maintain clearance |
| Terminal swing | ~30° flexion | Full extension | Neutral | Hamstrings decelerate the shank eccentrically |
The Highest-Yield Muscle Facts in Gait: The dorsiflexors work eccentrically at loading response (they lower the forefoot; they do not lift it), the gluteus medius stabilizes the pelvis in single-limb stance, and the hamstrings act eccentrically in terminal swing to stop the leg whipping into extension. Three muscles, three phases, three classic deviations.
Temporal and Spatial Parameters
| Parameter | Definition | Typical Adult Value |
|---|---|---|
| Step length | Heel contact of one foot to heel contact of the opposite foot | ~70–80 cm |
| Stride length | Heel contact to next heel contact of the same foot (two steps) | ~140–160 cm |
| Step width (base of support) | Lateral distance between heel centres | ~8–10 cm |
| Cadence | Steps per minute | ~100–120 steps/min |
| Walking velocity | Distance per unit time; = (stride length × cadence) ÷ 2 | ~1.2–1.4 m/s |
| Toe-out angle | Foot progression angle relative to line of progression | ~5–7° |
Interpretation rules:
- A widened base of support with reduced cadence and shortened steps is the universal compensatory pattern for instability, whatever its cause — cerebellar, vestibular, proprioceptive, or simply fear of falling.
- Asymmetric step length localizes the problem: the shorter step is usually taken by the sound limb, because the patient spends less time in single-limb stance on the painful or weak side.
- Gait velocity is a powerful global outcome measure. Because it integrates strength, balance, endurance, and confidence, it is a practical way to document functional progress across a plan of care.
Pathological Gait Patterns
| Gait Pattern | What You See | Responsible Lesion | First-Line Intervention |
|---|---|---|---|
| Antalgic | Markedly shortened stance time on the painful limb; the patient hurries off it | Pain in any weight-bearing structure of that limb | Identify and treat the pain generator; offload |
| Trendelenburg | Pelvis drops on the swing (contralateral) side during stance on the affected limb | Gluteus medius weakness on the stance side (superior gluteal nerve, L5) | Progressive hip abductor strengthening, side-lying and weight-bearing |
| Compensated Trendelenburg (gluteus medius lurch) | Trunk lurches laterally toward the stance limb to move the centre of mass over the hip | Same weakness, with a trunk compensation | Same; correct the compensation as strength returns |
| Steppage (foot drop) | Exaggerated hip and knee flexion in swing; audible foot slap at contact | Dorsiflexor weakness — common fibular nerve palsy or L4–L5 radiculopathy | Ankle-foot orthosis for clearance plus dorsiflexor strengthening; find the nerve lesion |
| Gluteus maximus (lurch) | Posterior trunk thrust at initial contact to lock the hip | Gluteus maximus weakness (inferior gluteal nerve) | Hip extensor strengthening, bridging to loaded hip hinge |
| Quadriceps avoidance | Trunk lurches forward over the stance limb; knee kept extended | Quadriceps weakness (femoral nerve, L3–L4) or ACL deficiency | Quadriceps strengthening; address knee stability |
| Circumduction | Swing limb swings out in a lateral arc | Functional leg-length excess: knee or hip stiffness, extensor spasticity, foot drop | Restore knee flexion/dorsiflexion; orthosis |
| Vaulting | Rises onto the toes of the stance limb to clear the opposite swing limb | Same clearance problem, opposite compensation | As above |
| Ataxic | Wide base, irregular and unequal steps, staggering, poor heel-toe | Cerebellar disease, or sensory ataxia from posterior column loss | Neurological referral; balance and sensory substitution training |
| Parkinsonian (festinating) | Stooped posture, shuffling short steps, reduced arm swing, accelerating festination, freezing | Basal ganglia disease | Medical management plus cueing-based gait training |
| Spastic hemiplegic | Circumducted, extended stiff leg with plantarflexed foot; flexed adducted arm | Upper motor neuron lesion, typically post-stroke | Neurological rehabilitation; tone management; orthosis |
| Scissoring | Knees and thighs cross the midline with each step | Bilateral hip adductor spasticity, classically spastic diplegic cerebral palsy | Tone management and adductor lengthening strategies |
Sensory vs. Cerebellar Ataxia: Ask the patient to stand with feet together and close their eyes. A patient whose balance is markedly worse with the eyes closed has sensory (proprioceptive) ataxia — a positive Romberg sign, indicating posterior column or peripheral sensory loss. A patient who is equally unsteady with eyes open has cerebellar ataxia; the Romberg is negative because vision was never compensating.
Conducting the Observational Examination
- Expose the segment. Shorts and bare feet. Gait cannot be judged through trousers.
- Observe from all three planes — from behind, from the front, and from both sides — over at least several cycles in each.
- Work one joint at a time, then one phase at a time. Trying to see everything at once is how deviations get missed.
- Add stress tests: ask for fast walking, slow walking, walking a tight rope line, heel walking (screens L4–L5 dorsiflexors), and toe walking (screens S1 plantarflexors). Mild deviations appear under speed or challenge.
- Correlate with the static examination. A Trendelenburg gait should be matched by a positive single-leg stance test and measurable abductor weakness; if it is not, reconsider the explanation.
- Screen footwear. The wear pattern on the patient's own shoes is free longitudinal data on foot mechanics.
Foot Mechanics Within Stance
Normal walking involves controlled pronation from initial contact through early mid-stance — the foot unlocking into a mobile adapter that absorbs shock — followed by resupination through terminal stance, which converts the foot into a rigid lever for push-off. Excessive or prolonged pronation keeps the foot mobile when it should be rigid, drives obligatory internal tibial rotation, and is the mechanical link between a hyperpronating foot and medial tibial stress syndrome, patellofemoral pain, and plantar fasciopathy.
During observational gait analysis of a 62-year-old with right hip pain, the clinician notes that each time the patient bears weight on the right leg, the left side of the pelvis drops below horizontal. Which muscle is weak, and on which side?
A patient walks with exaggerated hip and knee flexion during swing on the left and an audible slap as the left foot contacts the ground. Heel walking on the left is impossible. Which lesion best explains this presentation?
Which statement about the temporal structure of normal adult walking is correct?
A patient with a wide-based, staggering gait is asked to stand with feet together. With eyes open the patient is mildly unsteady; with eyes closed the patient sways markedly and nearly falls. What does this indicate?