Question regarding Muscle Contraction for Frog Gastrocnemius

Hey Gina, I'm not too sure what your question is (you haven't stated it definitely). Generally, neurons (sensory & motor) fire in an all-or-nothing fashion. Thus, they cannot fire partially. An intense stimulus may recruit more neurons to fire, and they may fire more times per second.

The strength of a skeletal muscle contraction bears a direct relationship to the initial length of its fibers, their metabolic condition, and the number of them contracting. If a muscle is moderately stretched at the moment when contraction begins, the force of its contraction increases.

With adequate amounts of these essentials a muscle can contract with greater force than is possible with deficient amounts. The greater the number of muscle fibers contracting simultaneously, the stronger the contraction of a muscle. How large this number is depends on how many motor units are activated, and this in turn depends on the intensity and frequency of the stimulation. In general, the more intense and more frequent a stimulus, the more motor units and therefore the more fibers are activated and the stronger the contraction.

Another factor that influences the force of contraction is the size of the load imposed on the muscle. Within certain limits, the heavier the load, the stronger the contraction.

Attached is a lab that may help you!
Link to lab