# Activity 7 isotonic contractions and the load velocity

Which of the weights allowed the fastest muscle shortening velocity? When lifting a heavy load You correctly answered: Review Sheet Results If you were using your bicep muscles to curl a 7-kg dumbbell, when would your muscles be contracting isotonically?

### Activity 7 isotonic contractions and the load velocity

When the arm rises from the down position back to the raised position and when your arm extends downwards to the point of it being straight Explain why the latent period became longer as the load became heavier in the experiment. How well did the results compare with your prediction? The latent period became longer because it takes more time to generate the force required.

It counteracts with my prediction.

Explain why the shortening velocity became slower as the load became heavier in this experiment. Maximal shortening velocity is only attained with a minimal load. With a light load, the shortening velocity is at its Maximal shortening velocity.

When the weight is heavy, the speed in which the muscle lifts the weight decreases in speed at a slower velocity. Thus shortening velocity bacame slower as I predicted. Describe how the shortening distance changed as the load became heavier in this experiment. The shortening distance decreased with the heavier load. This result counteracts with my prediction.

## Activity 7 isotonic contractions and the load velocity

Explain why it would take you longer to perform 10 repetitions lifting a 10-kg weight than it would to perform the same number of repetitions with a 5-kg weight. Because as the weight of the load increases, the latent period time increases and the shortening velocity speed decreases. With the lighter weight, the muscle is contracted quicker in both latent and shorteningvelocity speeds Describe what would happen in the following experiment: Simultaneously, the muscle is maximally stimulated by 8.

Will the muscle generate force? Will the muscle change length? What is the name for this type of contraction?

The force is generated from stretching the muscle caused by the recoil of the tissue. The muscle changing length would not be from the result of muscle contractions, but only from the weight pulling down.

This type of contraction would be Isometric.