Lecture 2: Mechanics of Locomotion Flashcards
adduction
toward median plane
abduction
away from median plane
inward rotation
relative to long axis
outward rotation
relative to long axis
circumduction
conical movement
combo of all other movements (rotation, abduction, adduction)
pronation
rotates forepaw caudally
supination
rotates forepaw cranially
pronation and supination: definition
partial rotation of the proximal extremity of the radius within annular ligament of the ulna while the distal extremity is carried in an arc around the ulna
plantigrade
walking on soles of feet/hands
digitigrade
walking on fingers/toes
not touching ground with heels
unguligrade
walking on hooves (specialized fingertips)
location of limb mass with extended distal limbs (and why/importance)
concentrated close to trunk
more muscle further from body requires more torque and energy to move
how do elongated limbs provide energetic savings
larger animals have lower metabolic rate –> can have limbs further from body = cost of locomotion is less
synovial sheaths function
pulley for long tendon
reduce friction
retinacula: definition, function
contain flexors and extensors
pulley for long tendon
tendon groups that pass under a band of connective tissue
advantage of elongated tendons for energy storage
short muscle belly + elongated tendon = stores elastic energy for movement
stretch and elastic recoil**
is there an energetic cost associated with standing
yes
what contracts to maintain a standing quadrupedal posture
limb and back extensors
what can smaller animals do during locomotion that large animals can’t
increase stride length with vertebral column flexion/extension
support phase of gait cycle begins with
heel strike
swing phase of gait cycle begins with
toe off
how do flexors and extensors relate during walking (hint: EMG)
fire at different times
counteract each other to work together
