Musculoskeletal Lab

Question 1

origin

Answer 1

a muscle’s attachment to the bone that moves the least

Question 2

insertion

Answer 2

a muscle’s attachment to the bone that most the most

Question 3

flexion

Answer 3

• to decrease a joint angle anterior to joint
• knee is an exception -> to decrease a joint angle posterior to joint

Question 4

extension

Answer 4

• to increase a joint angle anterior to joint
• knee is an exception -> to increase a joint angle posterior to joint

Question 5

chicken leg bone anatomy (superior to inferior)

Answer 5

• 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)

Question 6

shank

Answer 6

• 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)

Question 7

origin, insertion, movement at knee, synergist, and equivalent in humans of lateral and medial knee flexor

Answer 7

• 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)

Question 8

origin, insertion and equivalent in humans of iliotibial muscle

Answer 8

• origin -> ilium
• insertion -> tibiotarsus
• equivalent -> gluteus maximus

Question 9

origin, insertion, movement at hip joint and knee, synergist and human equivalent of iliofibular muscle

Answer 9

• 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

Question 10

position of lateral iliotibial muscle and iliofibular muscle in lateral view

Answer 10

• lateral iliotibial muscle is most superficial
• needs to be cut to see iliofibular muscle which lies beneath

Question 11

gastrocnemius muscle

Answer 11

• muscle covering shank
• equivalent to gastrocnemius muscle in humans

Question 12

shape of iliofibular muscle

Answer 12

• broad at proximal/pelvic end
• tapers distally

Question 13

position of lateral and medial knee flexor in medial view

Answer 13

• 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

Question 14

knee flexor muscle tendon

Answer 14

• lateral and medial knee flexor muscles come together to share the same tendon
• thin, flat, ribbon-like aponeurosis
• has two parts -> large and small

Question 15

posterior part of knee flexor muscle tendon

Answer 15

• 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

Question 16

lateral knee flexor accessory muscle

Answer 16

• 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

Question 17

requirement for muscle to move skeleton

Answer 17

must cross at least one joint

Question 18

biceps femoris muscle

Answer 18

• 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

Question 19

movement of hip joint following contraction of biceps femoris

Answer 19

• long head -> extension
• short head -> nothing, does not cross hip joint

Question 20

movement of knee joint following contraction of biceps femoris

Answer 20

• both heads -> flexion

Question 21

function and human equivalent of sling

Answer 21

• 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

Question 22

amplitude and power of distal attachment

Answer 22

• low amplitude
• high power

Question 23

amplitude and power of proximal attachment

Answer 23

• high amplitude
• low power
• e.g. iliofibular muscle

Question 24

synergist vs antagonist

Answer 24

• synergist -> aids/assists action of another muscle
• antagonist -> opposes action of another muscle

Question 25

hamstring muscles of human thigh

Answer 25

- 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

Question 26

concentric contraction

Answer 26

- muscle is stimulated enough so contractile force > external force - muscle shortens

Question 27

eccentric contraction

Answer 27

- muscle is stimulated but contractile force < external force - muscle lengthens - causes most damage -> builds new muscle

Question 28

isometric contraction

Answer 28

- muscle is stimulated so contractile force = external force - muscle length does not change

Question 29

phases of gait cycle and types of contraction

Answer 29

- heel strike - isometric contraction - foot flat - concentric contraction - mid-stance - eccentric contraction - push-off - isometric contraction - toe off - concentric contraction - mid-swing - eccentric contraction

Question 30

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'?

Answer 30

- hamstrings are stimulated to decelerate swinging limb - eccentric contraction

Question 31

what are the hamstring muscles trying to do between the phases of 'heel strike' and 'foot flat' at the hip joint?

Answer 31

- to prevent excessive hip flexion as weight is transferred onto the leg that just hit the ground - isometric contraction

Question 32

what are the hamstring muscles trying to do between the phases of 'foot flat' and 'mid-stance' at the hip joint?

Answer 32

- extend hip - concentric contraction - forward momentum is the main hip extensor so hamstrings are less stimulated as the mid-stance phase progresses