What happens during the repair phase of rehabilitation?

• A. Cells lay down new collagen fibers, scar tissue forms, pain decreases.
• B. Cartilage erosion increases.
• C. Bone remodeling accelerates.
• D. Muscle atrophy occurs.

Answer: (A)

The repair phase is when damaged tissue begins to rebuild itself by laying down new collagen and forming scar tissue to bridge the injury. Fibroblasts synthesize collagen fibers, and new tissue vascularizes to supply nutrients. This process reduces swelling and pain as inflammation settles, but the newly formed scar is initially weaker and less organized than the original tissue. Rehabilitation at this stage uses controlled loading to guide realignment of collagen fibers along functional stresses, improving strength and flexibility over time. The other scenarios describe processes not characteristic of this phase: cartilage erosion denotes ongoing degeneration, bone remodeling is specific to bone healing, and muscle atrophy is primarily a result of disuse rather than tissue regeneration during repair.