Shoulders: A Guide to Common Injuries and Treatments

The shoulder is the most mobile joint in the body, which also makes it one of the most vulnerable. It relies heavily on the muscles, tendons, and soft tissue structures around it for stability – and when any of those structures are irritated or weakened, pain and limited movement can follow.

Shoulder conditions are especially common in people managing osteoarthritis, partly because compensations elsewhere in the body can change how the shoulder moves, and partly because many everyday tasks – reaching overhead, getting dressed, lifting – rely on the shoulder working well.

Understanding the Shoulder

The shoulder is made up of three bones – the upper arm bone (humerus), the shoulder blade (scapula), and the collarbone (clavicle) – along with a shallow socket joint, a ring of cartilage (the labrum), multiple bursae, and a group of four muscles and tendons called the rotator cuff.

The rotator cuff is central to almost every shoulder condition. These four muscles – supraspinatus, infraspinatus, teres minor, and subscapularis – work together to keep the ball of the joint centered in the socket as the arm moves. When they are weak, tight, or injured, other structures take on more load than they’re designed for.

The shoulder also doesn’t work in isolation. How well your upper back moves, how you hold your posture, and whether your shoulder blade moves properly all affect what happens at the shoulder joint itself. This is why strengthening the upper back and working on posture are such consistent recommendations across nearly every shoulder condition.

1. Shoulder Impingement

What It Is

Shoulder impingement occurs when the tendons of the rotator cuff (most often the supraspinatus) get pinched or compressed in the narrow space between the top of the arm bone and the bony arch above it (the acromion). It’s one of the most common causes of shoulder pain, particularly with overhead activities.

It typically develops gradually from repetitive overhead movements, muscle imbalances, or poor posture – particularly a rounded upper back or forward head position, which tilts the shoulder blade in a way that reduces that space even further.

Pain is usually felt on the outside or front of the shoulder and is worst when lifting the arm to the side or overhead, or when reaching behind the back.

What Makes It Worse

• Overhead activities – reaching up, lifting overhead, painting, or washing hair
• Sleeping on the affected shoulder
• Rounded upper back posture, which reduces the space in the shoulder joint
• Weakness in the rotator cuff and scapular muscles, which allows the arm bone to ride too high in the socket
• Rapid increases in overhead activity

How to Help Prevent It

• Maintain good upper back posture and thoracic mobility – a rounded back directly narrows the shoulder space
• Keep the rotator cuff and scapular stabilizer muscles strong
• Avoid rapid increases in overhead activities
• Build gradually into any new activities that involve sustained arm use

Strategies to Manage It

• Rotator cuff and scapular strengthening – this is the primary and most evidence-supported treatment for impingement
• Isometric exercises are a good starting point when the shoulder is irritated, as they strengthen without loading the joint through a range that provokes symptoms
• Thoracic (upper back) mobility work – improving how the upper spine moves can meaningfully change the mechanics at the shoulder
• Temporarily reduce or modify overhead movements while symptoms are active
• Cortisone injections may provide short-term relief but do not address the underlying cause; exercise remains the most effective long-term treatment
• Surgery is rarely needed and is typically only considered after a consistent, thorough trial of conservative management

Modifications for Adventurers for Life

• Check out the Rescue Remedy for Shoulder Stiffness and Pain in the Workout Library – isometric exercises for external rotation, internal rotation, flexion, and extension. These are an excellent starting point when the shoulder is irritated and a useful warm-up before any workout
• Reduce or temporarily avoid overhead pressing movements if they provoke symptoms – substitute with movements that keep the arm below shoulder height
• Focus on pulling movements (rows, band pull-aparts) that strengthen the upper back and help correct the posture that contributes to impingement
• Use a mirror during upper body exercises to check that you’re not shrugging or hiking the shoulder up

2. Rotator Cuff Strain and Tendinopathy

What It Is

The rotator cuff can be injured in two main ways: an acute strain or tear (from a fall, sudden force, or lifting something heavy), or a gradual tendinopathy (where the tendon becomes irritated and degenerates over time from repetitive overload).

Tendinopathy is far more common than acute tears, particularly in people managing osteoarthritis. It develops when the tendon is exposed to more load or repetition than it can handle – and like the hip and knee tendons, the answer is not rest alone but rather loading the tendon appropriately to help it adapt and strengthen.

Symptoms typically include pain on the outside or front of the shoulder, weakness when lifting the arm, and sometimes a catching or clicking sensation. Pain at night – particularly when lying on the affected side – is common and can be one of the most disruptive aspects of rotator cuff conditions.

What Makes It Worse

• Sleeping on the affected side
• Reaching overhead or behind the back
• Lifting with the arm away from the body (especially with the arm internally rotated – thumb pointing down)
• Rapid increases in upper body activity or load
• Static stretching of an already irritated tendon
• Complete rest for extended periods, which allows the tendon to become less tolerant to load

How to Help Prevent It

• Consistent rotator cuff and scapular strengthening – the tendons need regular, progressive loading to stay healthy
• Avoid sudden large increases in upper body activity
• Maintain good posture – forward head and rounded shoulder posture places the rotator cuff in a mechanically disadvantaged position
• Warm up before upper body activity, particularly if the shoulder has been sedentary

Strategies to Manage It

• Progressive loading of the rotator cuff tendons – isometrics first, then gradual introduction of movement through a comfortable range, then progressive strengthening
• Scapular stabilization exercises – the shoulder blade needs to move well for the rotator cuff to work efficiently
• Upper back and postural strengthening
• Modify painful movements temporarily rather than avoiding all shoulder activity
• Night pain management – sleeping with a pillow supporting the arm can reduce compression on the tendon

Modifications for Adventurers for Life

• The Rescue Remedy for Shoulder Stiffness and Pain is directly applicable here – the isometric movements for external rotation, internal rotation, flexion, and extension are a research-supported approach for tendon rehabilitation. Use it as a daily warm-up or on its own during flare-ups
• Reduce weight on any upper body pressing or overhead movements while symptoms are active
• Rowing and pulling movements are generally better tolerated than pressing movements during a flare – prioritize these
• Avoid letting the arm hang heavily at the side during walks if the shoulder is irritated – a light support or sling for short periods can help during acute flare-ups
• If sleeping on the shoulder is causing significant night pain, try sleeping on your back with a pillow under the arm, or on the opposite side with a pillow hugged to the chest

3. Frozen Shoulder (Adhesive Capsulitis)

What It Is

Frozen shoulder is a condition where the capsule surrounding the shoulder joint becomes inflamed and then progressively thickens and tightens, significantly limiting range of motion in all directions. It typically progresses through three stages: a painful freezing phase, a frozen phase where pain may reduce but stiffness is severe, and a thawing phase where motion gradually returns.

The entire process can take one to three years, sometimes longer. It’s more common in people with diabetes, thyroid conditions, or a history of shoulder injury or surgery. It can also develop after a period of immobilization or reduced arm use – which is one reason staying as mobile as possible is so important.

What Makes It Worse

• Prolonged immobility or complete rest – avoiding movement accelerates the freezing process
• Aggressive stretching during the inflammatory (freezing) phase – forceful stretching of an inflamed capsule can increase pain and set back recovery
• Unmanaged diabetes or other metabolic conditions, which are associated with more severe and prolonged cases

How to Help Prevent It

• After any shoulder injury, surgery, or period of reduced arm use, maintain as much gentle movement as is safe and comfortable – even small pendulum movements help prevent the capsule from tightening
• Manage underlying metabolic conditions such as diabetes, which significantly increases the risk
• Address shoulder pain early rather than guarding and restricting movement for extended periods

Strategies to Manage It

• Gentle, consistent movement within a comfortable range – the goal is to maintain what you have and gradually expand it, not to force range of motion
• During the thawing phase, progressive range of motion work and rotator cuff strengthening become more appropriate
• Heat before movement can help loosen the capsule and make exercise more comfortable
• Cortisone injections during the early painful phase may help manage inflammation and allow more movement – this is one condition where they are more commonly recommended, particularly in the freezing stage
• Physiotherapy, including manual therapy and guided progressive movement, is a mainstay of treatment
• Surgery (manipulation under anesthesia or capsular release) is occasionally used in severe or non-resolving cases, but most cases do resolve with time and consistent conservative management

Modifications for Adventurers for Life

• The Rescue Remedy for Shoulder Stiffness and Pain can be used gently during the frozen and thawing phases – start within a completely comfortable range and do not push into pain
• Focus workouts on what you can do – lower body, core, and the unaffected arm – while the shoulder is in the freezing or frozen phase
• Pendulum exercises (letting the arm gently swing with gravity) can be a good starting point during more acute phases when active movement is limited
• As the thawing phase progresses, gradually reintroduce upper body movements, starting with movements that keep the arm below shoulder height and work up from there
• Use a mirror to check that you’re not compensating by hiking the shoulder or leaning to one side to achieve range of motion

4. Shoulder Bursitis

What It Is

Bursae are small fluid-filled sacs that reduce friction between structures in the shoulder. The subacromial bursa – sitting between the rotator cuff and the acromion – is the most commonly irritated. When it becomes inflamed, it produces pain at the top or outside of the shoulder, often worse with overhead movements and when lying on the shoulder at night.

Shoulder bursitis rarely occurs in isolation. It is very often a downstream effect of rotator cuff weakness or impingement – when the rotator cuff doesn’t hold the arm bone down and centered in the socket efficiently, extra compression is placed on the bursa. Treating the bursitis alone without addressing the underlying muscle imbalance typically leads to recurrence.

What Makes It Worse

• Overhead activities and repetitive arm use at or above shoulder height
• Lying on the affected shoulder
• Rapid increases in activity volume
• Poor shoulder blade mechanics – if the scapula isn’t moving well, the space available for the bursa decreases
• Prolonged static postures with rounded shoulders

How to Help Prevent It

• Rotator cuff and scapular strengthening – the primary prevention strategy
• Upper back postural work
• Gradual increases in upper body activity
• Avoid sustained overhead postures without adequate preparation

Strategies to Manage It

• Rotator cuff and scapular strengthening, as with impingement – addressing the underlying cause is the most effective approach
• Temporarily reduce overhead and repetitive arm movements during a flare
• Ice or heat depending on what provides more relief – ice is typically preferred in the first 48 to 72 hours after an acute flare; heat can help with ongoing stiffness
• Cortisone injections may provide short-term relief during an acute flare but do not address the underlying muscle imbalance

Modifications for Adventurers for Life

• The Rescue Remedy for Shoulder Stiffness and Pain is a good tool here – the isometric exercises load the rotator cuff without compressing the bursa through a painful range of motion
• Pulling and rowing movements are generally more comfortable than overhead pressing during a bursitis flare – prioritize these in workouts
• Reduce weight and repetitions on any movement that recreates the shoulder pinching sensation
• Check posture during seated and standing exercises – rounded shoulders reduce the subacromial space and increase compression on the bursa

5. AC Joint Issues

What It Is

The acromioclavicular (AC) joint is where the collarbone meets the top of the shoulder blade. It can be injured acutely (from a fall onto the shoulder or outstretched hand – a common mechanism in sports or a slip on ice) or it can develop gradual wear and degeneration over time, similar to osteoarthritis in other joints.

Pain is typically felt right at the top of the shoulder, at the bony prominence you can feel there. It’s often worse when the arm is brought across the body (horizontal adduction) – reaching across to the opposite shoulder, for example – or when lifting the arm overhead beyond a certain point.

What Makes It Worse

• Reaching across the body – crossing the arm over the midline
• Overhead pressing and heavy lifting
• Lying on the affected shoulder
• Carrying heavy loads in the hand of the affected arm (grocery bags, weights at the side)
• Push-up type movements that load the joint at end range

How to Help Prevent It

• Fall prevention – strength and balance training reduces the risk of the falls that commonly cause acute AC joint injuries
• Avoid sudden large increases in overhead or heavy pressing activity
• Rotator cuff and shoulder strengthening to support good joint mechanics

Strategies to Manage It

• Modify movements that load the joint in the painful range – particularly across-body movements and overhead pressing
• Rotator cuff and scapular strengthening remains important, as good muscle support reduces stress on the AC joint
• For acute injuries, a short period of rest and protection followed by progressive reloading is the standard approach
• For degenerative AC joint changes, conservative management with exercise and activity modification is usually very effective
• Cortisone injections may reduce pain in the short term but don’t appear to carry over into long-term relief and don’t address the underlying cause
• Surgery is rarely needed for degenerative AC joint conditions; acute high-grade separations may sometimes require surgical stabilization

Modifications for Adventurers for Life

• The Rescue Remedy for Shoulder Stiffness and Pain can be used as a warm-up – the isometric movements avoid loading the AC joint in its most provocative positions
• Avoid or reduce movements that bring the arm across the body (across-body stretches, fly-type movements) during active flare-ups
• Reduce the depth and load of any pressing movements – a shallower range that stops before the pinching point is often well tolerated
• Carrying weights at the side can compress the AC joint – if this is provoking symptoms, hold weights closer to the body or switch to a different grip temporarily
• Focus on rowing and pulling movements, which tend to be better tolerated than pressing

6. Shoulder Labral Tears

What It Is

The labrum is a ring of cartilage that lines the shoulder socket, deepening it and helping to keep the ball of the joint stable. Like the hip labrum, it can tear from trauma (a fall, dislocation, or sudden forceful movement), or it can develop degenerative changes over time.

There are different types of labral tears depending on where the tear is located. A SLAP tear (Superior Labrum Anterior to Posterior) occurs at the top of the socket and is particularly associated with overhead activities. Other tears can occur at the front or back of the socket, sometimes in connection with instability or a dislocation history.

Symptoms can include a deep aching pain in the shoulder, catching, clicking, or a feeling of the shoulder being unstable or giving way. Symptoms may be provoked by specific movements – particularly overhead, behind-the-back, or rotational activities.

What Makes It Worse

• Overhead activities and movements that take the arm to end range
• Rotational movements, particularly with the arm elevated
• Activities that involve the arm being forced backward or into an awkward position
• Instability and lack of muscular support around the joint, which increases the load on the labrum

How to Help Prevent It

• Rotator cuff and shoulder stability training – strong muscles reduce the demand on the labrum to provide passive stability
• Fall prevention and balance training to reduce the risk of traumatic shoulder injuries
• Warm up before activities that involve end-range or overhead shoulder movements

Strategies to Manage It

• Rotator cuff and scapular strengthening – when the muscles do their job well, the labrum is under less stress
• Shoulder stability and proprioception work
• Identify the specific movements that provoke symptoms and modify those while continuing to train the shoulder in comfortable ranges
• Avoid end-range positions under load until symptoms have settled and strength has improved
• Conservative management is the recommended first step and is often highly effective, particularly for degenerative tears

Modifications for Adventurers for Life

• The Rescue Remedy for Shoulder Stiffness and Pain is a good starting point – the isometric movements build rotator cuff strength without loading the shoulder at end range
• Reduce or temporarily avoid overhead movements and movements that take the arm behind the body
• Focus on movements that keep the arm in a comfortable, stable range – typically below shoulder height and in front of the body
• Use upper body support during any exercise that challenges shoulder stability, particularly during periods of active symptoms
• Rowing movements and exercises that keep the elbow close to the body are generally well tolerated

A Note on Posture and the Upper Back

Across every shoulder condition in this guide, one theme appears consistently: the health of the shoulder depends significantly on how the upper back and shoulder blade move. A rounded upper back (thoracic kyphosis) tilts the shoulder blade forward, reduces the space available inside the joint, and puts the rotator cuff in a mechanically disadvantaged position for nearly every movement.

This is why the back and posture strengthening work in Adventurers for Life is relevant not just for the spine but for the shoulder too. Improving thoracic mobility, strengthening the muscles between the shoulder blades, and working on scapular control are as important as any direct shoulder exercise.

Workout Library Resources

The following resource in the Workout Library is referenced throughout this guide:

• Rescue Remedy: Shoulder Stiffness and Pain (Rotator Cuff) – isometric exercises for shoulder external rotation, internal rotation, flexion, and extension. Perform 5 to 8 repetitions holding each for 3 to 5 seconds. Use as a warm-up before any workout, on its own during a flare-up, or as a daily maintenance routine.
• Back and Posture Strengthening workouts – directly support shoulder health by improving upper back strength and thoracic mobility
• Anterior Pelvic Tilt Videos – core and postural work that supports the full kinetic chain, including shoulder mechanics