For muscle injuries i.e. tissue damage, rehab. This is true even if for the same exercise you may have injured yourself on at a heavier weight. For cartilage damage high reps also work well. Presses however work better for joint and cartilage rehab. than isolation exercises because presses,and squats allow un afflicted muscles, ligaments and cartilage to kick in to assist the damaged area in moving through the motion. This is important to know because the assisting undamaged parts relieve the affected parts from carrying the full load while the increased blood pressure and motion brings in an abundant supply of enzymes and other elements to the damaged area for rejuvenation while lessening the chance for collateral damage often caused by isolation exercises such as leg extensions or tricep extensions.
Isolation exercises move only one joint at a time and can at times making healing much slower.