Final answer:
The heavy, rhythmic percussion involving the use of the therapist's closed, soft fist can be classified as a massage technique called closed fist percussion. This technique is commonly used in massage therapy and physical therapy to stimulate blood circulation, relax muscles, and release tension.
Step-by-step explanation:
The heavy, rhythmic percussion involving the use of the therapist's closed, soft fist can be classified as a massage technique called closed fist percussion. This technique is commonly used in massage therapy and physical therapy to stimulate blood circulation, relax muscles, and release tension. It is performed by rhythmically striking the client's body using the therapist's closed fist.