Anatomy of locomotion

• Stance phase accounts for 60% of the gait cycle
• Swing phase accounts for 40% of the gait cycle
• Heel strike phase muscles

  • gluteus maximus - acts to decelarate forward motion of lower limb
  • quadriceps femoris - keeps leg extended at knee
  • anterior compartment of leg - maintains ankle in dorsiflexion, to position the heel for strike
• Midstance phase muscles

  • gluteus minimus/medius and tensor fascia lata - abduct the lower limb to help keep balance
  • foot invertors/evertors - contract to stabilise ankle joint
  • quadriceps femoris - stabilises knee in extension, supports weight of body
• Foot evertors - fibularis longus/brevis
• Foot invertors - muscles of anterior and posterior compartments
• Heel off phase muscles

  • hamstring muscles - extend thigh at hip
  • posterior compartment of lower leg - plantarflexes ankle
  • quadriceps femoris - maintain extended position of knee
• Toe off phase muscles

  • hamstring muscles - flexes leg at knee joint
  • iliopsoas and rectus femoris - flexes thigh at hip to drive knee forward
  • anterior compartment of leg - dorsiflexes the ankle
• Swing phase muscles

  • quadriceps femoris - extend leg at knee
  • iliopsoas and rectus femoris - keep thigh flexed at knee
  • anterior compartment - maintains ankle dorsiflexion so heel can land first
• Heel strike phase

  • continue deceleration
  • lower forefoot to ground
  • preserve longitudinal arch of foot
• Loading response phase

  • stabilise pelvis
  • accept weight
  • decelerate mass
  • preserve longitudinal arch of foot
• Midstance phase

  • stabilise pelvis
  • stabilise knee
  • preserve momentum of dorsiflexion
  • preserve longitudinal arch of foot
• Terminal stance phase

  • stabilise pelvis
  • accelerate mass
  • preserve arches of foot; fix forefoot
• Preswing phase

  • decelerate thigh; prepare for swing
  • accelerate mass
  • preserve arches of foot; fix forefoot
• Initial swing phase

  • accelerate thigh, vary cadence
  • clear foot
• Midswing phase

  • clear foot
• Terminal swing phase

  • decelerate thigh
  • decelerate leg
  • extend knee to place foot
  • position foot
• During running, more time spent in swing phase than in walking. As speed increases, stance phase decreases.
• Running has no double stance phase, instead there is a double float phase where neither foot is in contact with the ground.
• Vertical jump

  • crouching action initiates vertical jump. It involves rapid hip and knee flexion.
  • stretch of muscles which occurs during this movement generates greater potential energy for muscles to contract in subsequent jump
  • known as stretch-shortening cycle. Active stretch (eccentric contraction) followed by immediate shortening (concentric contraction) of same muscle
• Vertical jump muscles

  • hip extensors extend hip after initial squat. Includes gluteus maximus and hamstrings
  • knee extensors extend knee joint. quadriceps femoris
  • ankle plantarflexors - gastrocnemiuis and soleus plantarflex ankle joint to provide extra power
• Standing/orthostasis

  • body is held in erect position supported only by the feet
  • erector spinae muscles (back extensors) act to hold spine in extension and counteract the pull of gracity
  • gluteus medius and tensor fascia lata prevents hips swaying
  • centre of gravity post 1/3 of median plane, anterior to ankles
• There are 10 intrinsic muscles located in the sole of the foot. They act collectively to stabilise the arches of the foot. They are arranged in four layers underneath the plantar fascia and are all innervated by the medial or lateral plantar nerves.
• First layer of foot muscles

  • abductor hallucis
  • flexor digitorum brevis
  • abductor digiti minimi
• Second layer of foot muscles

  • quadratus plantae
  • lumbricals
• Third layer of foot muscles

  • flexor hallucis brevis
  • adductor hallucis
  • flexor digiti minimi brevis
• Fourth layer of foot muscles

  • plantar intersossei
  • dorsal interossei
• Trendelenburg gait

  • abductor muscles (gluteus medius and minimus) weak or paralysed
  • pelvis drops towards side of raised leg
  • leads to waddling gait
• Foot drop

  • damage to deep fibular nerve
  • supplies muscles in anterior compartment of leg (dorsiflexion)
  • compensation - hyperflexion of thigh to help dropped foot clear the floor aka high stepping gait
• Parkinsonian gait

  • tremor, rigidity and bradykinesia
  • slow to initiate movement
  • festinant gait - shuffling, pitched forward with reduced arm swing
  • freezing at obstacles due to poor simultaneous motor and cognitive function
  • caused by Parkinson's disease, drugs (dopamine antagonists) e.g. antipsychotics, antiemetics
• Hemiplegic gait

  • asymmetrical gait; one limb is normal while the affected limb is stiff (spastic)
  • affected limb held in extension (knee extension and foot plantarflexion) with feet inverted
  • toes on affected side may drag on floor due to fixed ankle plantar flexion and knee extension lengthening leg
  • affected leg swings around (i.e. circumducts) during the swing phase to prevent the feet from dragging
• Equinus ankle

  • acquired foot deformity commonly seen in paediatric patients with conditions such as cerebral palsy
  • patient's ankle joint is held in plantarflexion
  • during normal gait cycle, the ankle should be able to dorsiflex at least 10 degrees
  • equinus can be divided into muscular or osseus types
  • can be managed with nonoperative (serial casting or botox injections) or operative measures (osteotomy)
• Iliotibial band syndrome

  • common cause of lateral knee pain in athletes
  • results from repetitive friction of iliotibial band (fibres from both tensor fascia lata and gluteus maximus) over the lateral femoral epicondyle
  • management includes rest, strengthening of hip abductors and simple analgesics
• Patellar tendinitis (Jumper's knee)

  • inflammation of the tendon connecting the patella to the tibia
  • occurs through overuse/abnormal stress to the tendon
  • pain is felt just below the patella
  • treatment is with rest and analgesia
• Plantar fasciitis

  • overuse injury related to running/inappropriate footwear
  • straining and inflammation of plantar fascia of foot
  • pain located at proximal attachment of plantar fascia
  • can be related to calcaneal spur from medial tubercle
  • pain on dorsiflexion of ankle/weight bearing/extension of great toe
• Shin splints

  • also known as medial tibial stress syndrome
  • usually multifactorial. Training type, footwear and lack of rest can all be implicated
  • muscle attachments to the tibia stressed and unable to heal properly due to repeated use
  • diffuse pain along middle distal tibia associated with exertion
• Patellofemoral syndrome (Runner's knee)

  • pain deep to the patella
  • often results from excessive running
  • repetitive micotrauma caused by abnormal tracking of the patella relative to the patellar surface of the femur
  • may result from degenerative wear and tear of articular cartilages
  • strengthening vastus medialis may correct abnormal tracking. VM attaches to medial border or patella and prevents lateral dislocation of patella.
• Flat foot (pes planus)

  • aka fallen arches secondary to dysfunction of tibialis posterior owing to trauma, degeneration with age or denervation
  • plantar calcaenonavicular ligament then fails to support the head of the talus
  • talar head displaces, flattening of the medial longitudinal arch and lateral deviation of the forefoot
• Exertional compartment syndrome

  • majority of cases occur in the lower leg
  • presents with pain on exertion
  • four compartments in lower leg (anterior, lateral, superficial posterior and deep posterior) each covered by fascia
  • exertional compartment syndrome occurs when muscles expand during exercise and fascial covering becomes too tighy