What Happens to Muscles After Two Weeks of Not Moving (Hospital Stays, Illness, Casts)

Muscle adapts to the load you put on it. When a muscle is used less, it tends to lose strength and size, and illness, bed rest and immobilization are thought to make this more likely.

Muscle loss also becomes more common with age. Sarcopenia is the medical term for age-related muscle loss. It affects almost one in three older people, but losing muscle is not inevitable [R08].

In the shoulder, the effects can go beyond muscle size. Shoulder problems are often linked with reduced joint position sense, which is your ability to feel where the joint is without looking [R16]. Weakness and poor coordination often follow time in a sling or cast, which is one reason rehab plans move in stages.

If you want to understand the shoulder blade muscles in more detail, see 17 muscles of the shoulder blade. For how this topic sits within the wider shoulder myths, see 10 shoulder myths debunked.

• Resistance exercise is the first-line approach for muscle loss in older adults. No drug is available for this [R08].
• Strength training counters loss of muscle strength and mass in older adults. It also supports function, mobility, independence and quality of life [R06].
• Healthy older adults are generally advised to eat about 1.0 to 1.2 grams of protein per kilogram of body weight each day. People who are ill or at risk of malnutrition may need 1.2 to 1.5 grams [R09].
• Protein appears to help most when it is combined with resistance exercise [R08].
• Rehab for shoulder problems usually moves through stages: range of motion, then strength, then control and proprioception (your sense of joint position), then coordination [R16].

The sources here are about older adults and general muscle health. They are not studies of a two-week hospital stay specifically. Research on exact rates of loss varies, so we do not give a number we cannot source.

1. Ask your care team what movement is allowed. After a hospital stay, surgery or cast, follow the surgeon's or physiotherapist's plan first.
2. Start with small, seated movements. Sit tall and shrug your shoulders gently, then let them drop. Slowly squeeze your shoulder blades together and release. Stop before you feel sharp pain.
3. Add gentle resistance as you can. In shoulder pain research, resisted exercise that progresses over time probably helps more than unloaded movement [R01]. Seated option: use your other arm to provide light resistance during slow lifts.
4. Move through your day. The WHO advises adults to build up to 150 to 300 minutes of moderate activity a week. Older adults may need to start much smaller, and every move counts [R07]. Seated option: if standing or walking is not safe yet, do seated arm and leg movements.
5. Think about protein. Most healthy older adults are advised to aim for about 1.0 to 1.2 grams per kilogram per day [R09]. If you have kidney disease, check with your clinician or dietitian first [R08].
6. Track and talk. Note how your strength and range change over a few weeks. Bring the notes to your next appointment.