Final answer:
The sensation of stretch tension in the right pectoralis major during the length assessment indicates the tightness of that muscle, suggesting inflexibility or shorter muscle length.
Step-by-step explanation:
When a client is able to completely rest his elbows, wrist, and posterior hands on the floor during the pectoralis major length assessment, but feels tension in the right pectoralis major, this indicates tightness in the muscle. The sensation of stretch tension, despite the muscle being in a resting position, points to a degree of inflexibility or a shorter muscle length. This suggests that the muscle may benefit from flexibility exercises or stretching to improve its length and reduce tension. Muscle weakness, overactivation, or fatigue would present with other signs, such as an inability to maintain muscle contraction against resistance, excessive use during movement, or a quick drop in performance, none of which are indicated by the sensation of stretching alone.