During the lowering half of a controlled squat, the knee extensors remain active as they lengthen. Which action is occurring?
- AIsometric action
- BConcentric action
- CEccentric action
- DPassive elastic recoil
Show answer and explanations
Answer
C
The knee extensors produce force while lengthening to control knee flexion against gravity, which is an eccentric (deceleration) action.
A
An isometric action produces force without a change in muscle length; here the quadriceps lengthen as the knees bend.
B
A concentric action shortens the muscle; that happens on the way up, not during the controlled descent.
D
The stem states the extensors stay active; elastic recoil is a passive contribution at the turnaround, not the controlled lowering.
C
The knee extensors produce force while lengthening to control knee flexion against gravity, which is an eccentric (deceleration) action.