For a patient with a flexor tendon repair, the therapist has the patient place a rubber band around the fingers when they are together and then move them apart. What is the PRIMARY objective of this activity?

• A. Stretch the lumbricales
• B. Stretch the interossei
• C. Strengthen the lumbricales
• D. Strengthen the interossei

Answer: (D)

This activity targets the interossei, the intrinsic hand muscles responsible for finger abduction and adduction. When fingers are together and a rubber band is placed around them, they must contract to pull the fingers apart against resistance, strengthening the interossei. The lumbricals don’t produce finger spreading; they flex the metacarpophalangeal joints and extend the interphalangeal joints, so this exercise wouldn’t primarily strengthen them. Strengthening the interossei helps stabilize the finger joints and coordinate intrinsic–extrinsic muscle activity after a flexor tendon repair, supporting better tendon gliding and control.