jumping/landing Flashcards
___ mass resists upward jumping movement
larger
larger mass increases ____ downward to landing
velocity
what happens when a femur is disproportionally long to the trunk
excessive knee and back pain
when we land are we accelerating or decelerating
decelerate
is deceleration eccentric or concentric
eccentric
what are the two main bending points when landing
hips and knees
how much more is our body weight when landing
3x
drop jump landing v step landing
two legs v one
positive work is concentric or eccentric
concentric
how does impulse aid momentum in jumping
take off
how does impulse decrease momentum with jumping
landing
what affects moment of inertia the most
distribution of the mass
ground reaction force (GRF) increase with landing ____ and knee ____
height, extension
what can reduce GRF
effective instructions and auditory cues
reduced and poorly controlled knee flexion in males or females
females
ligaments connect
bone to bone
main knee ligament
ACL
how does an ACL get stretched
femur and tibia go in opposite directions
an ACL stretch is what type of force
tensile
what does the ACL connect
femur to tibia
what does the ACL do
stability, keep tibia from moving forward
how is the ACL commonly injured
combined horizontal forces
is an ACL tear more common in men or women
women
___% of ACL injuries are traumatic
30
___% of ACL injuries are non-contact (atraumatic)
70
4 main keys to ACL tear prevention
strength, plyometrics, neuromuscular training, enhance endurance
what muscle weakness causes valgus knees
glutes/hip rotators
6 proper landing technique
shoulders over knees
COG between base of support
feet shoulder width apart
no values at knees
knee in line with foot
soft landing, bend knees
heel toe landing results in ____ GRF compared to toe heel landing
greater
___ strength go the knee extensors is crucial to knee function
eccentric
glute med action
abduction
add/abduction is in what plane and axis
frontal, AP
glute max actions
hip extension, ER
which muscles are important to reduce knee injuries when lending
glute med, max, piriformis, other hip ER
which hip valves group is the largest
flexors
when we land properly the moment arm is larger or smaller
smaller
what test assesses landing
LESS
how do we fix landing issues
strengthen glutes, increase hip mobility, coach, feedback, plyometrics
