Musculoskeletal Lab Flashcards
origin
a muscle’s attachment to the bone that moves the least
insertion
a muscle’s attachment to the bone that most the most
flexion
- to decrease a joint angle anterior to joint
- knee is an exception -> to decrease a joint angle posterior to joint
extension
- to increase a joint angle anterior to joint
- knee is an exception -> to increase a joint angle posterior to joint
chicken leg bone anatomy (superior to inferior)
- spine/tail
- pelvis (i.e. ilium -> ischium -> pubis)
- hip joint
- femur
- knee joint
- shank (i.e. fibula -> tibiotarsus)
- intertarsal joint
- tarsometatarsus
- phalanges (i.e. four digits)
shank
- between knee joint and ankle joint of birds
- fused leg bones (i.e. large tibia and small fibula) and proximal foot bones (i.e. tarsals)
- forms single long bone (i.e. tibiotarsus) and slender bone partially fused alongside (i.e. fibula)
origin, insertion, movement at knee, synergist, and equivalent in humans of lateral and medial knee flexor
- origin -> ilium (i.e. lateral) and ischium (i.e. medial)
- insertion -> tibiotarsus
- movement at knee -> flexion
- synergist -> iliofibular muscle
- equivalent -> semimembranous (i.e. lateral) and semitendinous (i.e. medial)
origin, insertion and equivalent in humans of iliotibial muscle
- origin -> ilium
- insertion -> tibiotarsus
- equivalent -> gluteus maximus
origin, insertion, movement at hip joint and knee, synergist and human equivalent of iliofibular muscle
- origin -> ilium
- insertion -> fibula
- movement at hip joint -> extension
- movement at knee -> flexion
- synergist -> lateral and medial knee flexor
- equivalent -> long heat of bicep femoris
position of lateral iliotibial muscle and iliofibular muscle in lateral view
- lateral iliotibial muscle is most superficial
- needs to be cut to see iliofibular muscle which lies beneath
gastrocnemius muscle
- muscle covering shank
- equivalent to gastrocnemius muscle in humans
shape of iliofibular muscle
- broad at proximal/pelvic end
- tapers distally
position of lateral and medial knee flexor in medial view
- origin of lateral knee flexor is dorsal to orgin of medial knee flexor
- medial knee flexor lies on top of and partly covers lateral knee flexor
- lateral knee flexor forms most posterior edge of thigh
knee flexor muscle tendon
- lateral and medial knee flexor muscles come together to share the same tendon
- thin, flat, ribbon-like aponeurosis
- has two parts -> large and small
posterior part of knee flexor muscle tendon
- small part of knee flexor muscle tendon
- joins a dense fibrous fascia on surface of medial side of shank
- distally fascia becomes large strap-like tendon on posterior side of intertarsal joint
- equivalent of calcaneal/achilles tendon in human leg
lateral knee flexor accessory muscle
- short, flattened muscle
- fibres run at right angles to long axis of thigh
- joined to anterior edge of lateral knee flexor at its distal end
requirement for muscle to move skeleton
must cross at least one joint
biceps femoris muscle
- on posterior and lateral side of human thigh
- within posterior compartment
- has two heads
- long head -> originates from ischium, crosses hip joint and knee joint
- short head -> originates from posterior edge of femur, acts as sling, prevents bowstringing
- common tendon inserts on superior end of fibula
movement of hip joint following contraction of biceps femoris
- long head -> extension
- short head -> nothing, does not cross hip joint
movement of knee joint following contraction of biceps femoris
- both heads -> flexion
function and human equivalent of sling
- fibrous connective tissue sling that covers distal end of iliofibular muscle
- prevents iliofibular muscle from bow stringing away from knee joint
- allows for more effective movement of skeleton
- equivalent to short head of biceps femoris in humans
amplitude and power of distal attachment
- low amplitude
- high power
amplitude and power of proximal attachment
- high amplitude
- low power
- e.g. iliofibular muscle
synergist vs antagonist
- synergist -> aids/assists action of another muscle
- antagonist -> opposes action of another muscle
hamstring muscles of human thigh
- on posterior and medial side of human thigh
- within posterior compartment
- semimembranosus, semitendinosus, biceps femoris
- supplied by sciatic nerve
- biarticulate, cross two joints (i.e. hip and knee)
- position of hip can affect the knee and vice versa
concentric contraction
- muscle is stimulated enough so contractile force > external force
- muscle shortens
eccentric contraction
- muscle is stimulated but contractile force < external force
- muscle lengthens
- causes most damage -> builds new muscle
isometric contraction
- muscle is stimulated so contractile force = external force
- muscle length does not change
phases of gait cycle and types of contraction
- heel strike
- isometric contraction
- foot flat
- concentric contraction
- mid-stance
- eccentric contraction
- push-off
- isometric contraction
- toe off
- concentric contraction
- mid-swing
- eccentric contraction
what are the muscles in the posterior compartment of the thigh trying to achieve at the hip and knee joint just before the phase of ‘heel strike’?
- hamstrings are stimulated to decelerate swinging limb
- eccentric contraction
what are the hamstring muscles trying to do between the phases of ‘heel strike’ and ‘foot flat’ at the hip joint?
- to prevent excessive hip flexion as weight is transferred onto the leg that just hit the ground
- isometric contraction
what are the hamstring muscles trying to do between the phases of ‘foot flat’ and ‘mid-stance’ at the hip joint?
- extend hip
- concentric contraction
- forward momentum is the main hip extensor so hamstrings are less stimulated as the mid-stance phase progresses
