Final answer:
The condition described is not effectively captured by the provided options; it sounds like a normal muscle contraction resulting in a shortened state where further movement is limited by the muscle bulk.
Step-by-step explanation:
The phenomenon described, where muscle bulk is compressed resulting in a soft end feel and joint motion being stopped by the approximation of the structure at the joint, such as in elbow flexion, is related to muscular interactions during movements. This is not a description of muscle hypertrophy, spasm, strain, or atrophy. Muscle hypertrophy involves an increase in muscle size due to the addition of structural proteins. A muscle spasm is an involuntary contraction of a muscle.
Muscle strain is when muscle fibers tear due to overstretching, and muscle atrophy refers to the loss of muscle mass. Since none of the options fit the described scenario accurately, it might be a case of simple muscle shortening during a typical contraction where the muscle bulks up and the movement range is limited by the muscle reaching its maximum shortened state.