Anatomy of locomotion Flashcards
What is resting posture?
Minimal muscular activity
Feet splayed and slightly apart
Hips and knees extended
Which muscles make up the triceps surae?
Two headed gastrocnemius, soleus
What is static posture?
How you hold yourself when you’re not moving (sitting, standing, sleeping). Body segments aligned and in fixed positions. Usually achieved by coordination and interaction of various muscle groups
What does ITB do?
Locks knee in hyperextension (rigid support pillar, important stabilizer of knee in extension and partial flexion in walking and running
How does the popliteal contribute to resting posture?
Unlocks knee (lateral rotation of femur during stance, medially rotates tibia in swing). Posterior pull on lateral meniscus prevents crushing in knee flexion
Why is normal gait efficient?
Uses gravity and momentum, most energy in level walking is eccentric dorsiflexion after heel strike and plantar and toe flexion at push-off
What is a stride equivalent to?
2 steps
Process of walking
- Starts with ‘heel strike’ (heel on ground) and finishes with toe-off
- Hip and knee flex to draw limb forward
- Foot dorsiflexes immediately after toe-off so the foot clears the floor
- Hip abductors stabilize pelvic girdle and prevent pelvis dropping on contralateral side
Which muscle extends hip?
Gluteus maximus
Which muscles flex the knee?
Hamstrings (biceps femoris, semitendinosus, semimembranosus)
Which muscles do plantar flexion?
Gastrocnemius, soleus, plantaris, achilles tendon
Which muscles flex the hip?
Iliopsoas, rectur femoris, sartorius, pectineus, tensor dascia lata
Which muscles extend the knee?
Quadriceps
Which muscles perform dorsiflexion?
Tibialis anterior, extensor digitorum/hallucis longus
How much of normal gait is stance?
60%
How much of normal gait is standing?
40%
Characteristics of toddlers walk
Slower, high cadence, flexed elbows
What is the stretch shortening cycle?
Eccentric followed by concentric
What is a concentric action?
Muscles are shortened and force is produced
What is amortisation?
Stretched muscles store energy
What is an eccentric action?
Muscles actively lengthened
What is the flight stage?
Completely off ground
What is an asymmetrical gait?
One limb is normal and the other stiff
What is hemiplegic gait caused by?
MS and prolapsed vertebral disc
Characteristics of hemiplegic gait
Asymmetrical
Affected limb in extension with feet inverted
Ankle plantar flexion causes toes on affected side to drag on floor
Affected leg circumducts
Why do you circumduct your leg in abnormal gaits?
To prevent feet dragging on floor
Characteristics of spastic gait
Findings similar to hemiplegic gait but bilateral
Limbs stiff, feet inverted and internally rotated
Excessive adductor tone draws hips together
Spasticity causes leg overlap
Circumduction of both legs
What is spastic gait caused by?
Cerebral palsy
What is the parkinsonian gait caused by?
Tremor, rigidity, bradykinesia
Characteristics of parkinsonian gait
Short stepping, shuffling Minimal arm swing Difficulty when turning around/stopping walking/initiating new movements Stooped posture Hypomimia Hypokinetic gait
What is hypomimia?
Expressionless face
What causes ataxic gait?
Stroke, alcoholism, MS
Symptoms of ataxic gait
Broad based, unsteady, if unicerebellar lesion present, patient may lean towards affected side
What is a foot drop?
Weakness of dorsiflexion, so foot drops and toes drag during swing phase
What causes foot drop gait?
Motor weakness of nerves supplying tibialis anterior (common perineal nerve)
Characteristics of foot drop gait
Foot drop
High stepping gait
Feet stamping
What causes Trendelenburg gait?
Hypo/hyper parathyroidism
Acromegaly
Duchenne’s muscular dystrophy
Characteristics of Trendelenburg gait?
Hip abductors are weak (can’t contract and stabilise pelvis during stance phase)
Circumduction and waddling prevents foot from dragging
What is acromegaly?
Increased size of bones
What is the Trendelenburg sign?
Drop in pelvis when lifting leg opposite weak gluteus medius because of weak hip abductors
Compensated by leaning towards affected side to let affected leg come off ground
What is pes planus?
Flat foot
Arch collapses, can be congenital or acquired. Insufficiency of tib post or plantar fascia and calaneoclavicular joint
Talar head displaces interiomedially
What is ITB syndrome?
Iliotibialband syndrome
Iliotibial band is overused (e.g. long distance runners) causing it to become tight and inflamed
What is jumpers knee?
Inferior patella pain
What is shin splints?
Anterior shin pain (overexertion in untrained). Tib ant microtrauma on periosteum. DDx (stress fracture, compartment syndrome)
