It would make sense at face value, that you would want to completely immobilize a torn rotator cuff to let it heal. After all, this is the way bones heal best. The problem is that studying rotator cuff tear healing in an animal model can be difficult. Animals hate to be immobilized and often there’s no good way to immobilize them that’s anything like what we would use in a human. So some creative scientists came up with another way, they injected Botox to paralyze the rotator cuff muscle-the ultimate shoulder immobilizer! Regrettably, what happened is what often happens in today’s model of rotator cuff healing, while the tears healed quickly, the resulting healed rotator cuff tendon was weaker than tendons that healed on their own. This fits with other research on shoulder rotator cuff tears that atrophy of the rotator cuff muscles (the muscles shrink and become weaker due to disuse), is associated with a worse outcome from shoulder rotator cuff surgery. It turns out that we need activity to stress the healing rotator cuff tear area to allow it to heal strongly. For a massive rotator cuff tear this means gradual return to activities, but regrettably, while the months spent in a blue pillow shoulder immobilizer will help the sewn pieces heal, the repair will be less than optimal due to weakness in the tissue (hence the high re-tear rate for shoulder rotator cuff surgical repairs). For partial tears of the rotator cuff that won’t heal on their own, we believe in procedures that let the patient be as active as they feel able, as this will produce the stongest repair. For our clinic, this means injections to help the torn rotator cuff heal with activity, rather than sewing the area back together. Letting the patient move and use the shoulder while the rotator cuff heals, based on this and other research, all things being equal, will likely produce a stronger repair of a torn rotator cuff tendon.