Competitive weight lifters often try to exceed their own limits of performance by lifting heavier and heavier weights. Dwight is attempting to set his new personal record on the bench press and as he lowers the bar to his chest, he pushes it back up about halfway and begins to struggle. His spotter waits for two seconds while Dwight continues to work by himself, and suddenly the bar begins to move upwards again until it is fully extended, without the intervention of the spotter. Describe the types of muscle contractions that occurred while Dwight was struggling and while he followed through, respectively.
A) isometric, eccentric isotonic
B) isotonic, concentric isometric
C) eccentric, concentric isotonic
D) iosmetric, concentric isotonic

Question

Quizplus · Accepted Answer

When Dwight was struggling with the weight without moving it, his muscles were engaged in an isometric contraction, where the muscle length does not change despite force being applied. As he managed to push the bar upwards until it was fully extended, his muscles were performing a concentric isotonic contraction, where the muscles shorten while generating force.

Competitive Weight Lifters Often Try to Exceed Their Own Limits