Hand Injury and Shoulder Weakness: Connecting the Dots

If you have a hand injury does it stand to reason that your shoulder will be weaker? If the shoulder is weaker is it directly linked to the hand injury?

That's what this study is all about. Dr. Budoff from the Department of Orthopaedic Surgery at Baylor College of Medicine in Houston, Texas, put these questions to the test. He measured rotator cuff strength in 57 patients with a hand or wrist injury. The rotator cuff is made up of four muscles that surround the shoulder.

A handheld device called a dynamometer was used to measure grip strength. The dynamometer is known to be an accurate way to measure arm and shoulder strength. Each test was done three times with a 30-second rest in between all tests. Studies show this is the best way to measure upper extremity strength.

Other strength tests were also done. Each muscle of the rotator cuff was tested separately. Each type of injury was recorded along with which hand was dominant. About half the patients were on worker's compensation.

The results showed younger patients had a greater strength loss. This may be because they have more strength to lose than older patients who are weak to start. The type of injury (muscle versus bone) didn't seem to affect muscle strength. Shoulder weakness was greater when the nondominant hand was injured.

This study showed a significant loss in shoulder strength for the arm with an injured hand or wrist. Dr. Budoff isn't sure why this happens. It could be hand injuries lead to decreased use of the arm. The limb gets deconditioned. The rotator cuff gets weak and tired. He suggests starting a program of shoulder exercises sooner than later.



References: Jeffrey E. Budoff, MD. The Prevalence of Rotator Cuff Weakness in Patients with Injured Hands. In The Journal of Hand Surgery. November 2004. Vol. 29A. No. 6. Pp.1154-1159.