Shoulder Impingement: Why Lifting Your Arm Overhead Hurts

You reach for a top shelf, pull a jumper over your head, or press a barbell overhead, and there it is: a sharp pinch at the front or side of your shoulder. Sometimes it settles in seconds. Sometimes it lingers into the night and makes it hard to find a comfortable position in bed.

This pattern is very common, and it is usually called shoulder impingement. The name sounds alarming, but in most people it is a manageable problem that responds well to the right approach. Here is what is going on and what tends to help.

What "impingement" actually means

Your shoulder is a shallow ball-and-socket joint, which gives it a huge range of movement but relatively little built-in stability. To make up for that, a group of four small muscles, the rotator cuff, hold the ball snugly in the socket and guide it as you move.

Above the joint sits a bony roof called the acromion. Between the roof and the ball there is a narrow gap containing the rotator cuff tendons and a fluid-filled cushion called a bursa. When you lift your arm, that space naturally gets tighter. If the tendons or bursa are irritated, or the ball is not sitting quite centrally, they can get squeezed or rubbed against the bone. That is the "impingement", and it is why the pain tends to show up in a particular range, often somewhere between shoulder height and fully overhead.

You may hear it called subacromial pain, rotator cuff related shoulder pain or painful arc. These terms overlap. What matters more than the label is working out why your shoulder is irritable.

Why it happens

Rarely is there one single cause. More often it is a combination of factors:

• A sudden change in load. Starting a new overhead-heavy gym programme, taking up swimming or climbing, or a weekend of painting a ceiling can all overload tendons that were not ready for it.
• Desk posture and long hours at a screen. Sitting for long periods with rounded shoulders and a forward head position can change how the shoulder blade sits and moves, reducing the space available when you lift.
• A weak or tired rotator cuff and shoulder blade muscles. If these muscles are not doing their job of steering the joint, other structures take the strain.
• Stiffness. A tight upper back or tight tissues at the back of the shoulder can limit smooth movement and push the joint into a pinch.
• Age-related changes. Tendons gradually change with age, and shoulder pain is more common from our 40s onwards. This does not mean something is "worn out" or that you should stop using your arm.

Imaging often shows changes in the tendons of people with no pain at all, so a scan finding does not always explain your symptoms. A hands-on assessment of how you move usually tells us more.

What tends to help

Complete rest is rarely the answer. A sore tendon generally recovers better with sensible, gradually increasing load than with weeks of avoiding it. A typical approach looks like this:

1. Calm it down, don't shut it down. Ease off the specific movements that provoke sharp pain, such as heavy overhead presses or long reaching tasks, but keep the arm moving within comfortable limits. Some mild discomfort during exercise is usually acceptable if it settles soon afterwards.
2. Improve movement. Mobilising the upper back and gently restoring shoulder range can quickly make everyday reaching feel easier.
3. Build strength progressively. Rotator cuff and shoulder blade strengthening is the backbone of recovery. This usually starts with light, controlled exercises and builds towards loaded and overhead work. Our strength and conditioning approach to rehab is designed for exactly this kind of gradual progression.
4. Adjust your day-to-day. Small changes such as raising your monitor, varying your position through the day and sleeping with a pillow supporting the sore arm can take pressure off.

If a tendon has become stubbornly painful over several months, other options such as shockwave therapy can sometimes be considered alongside exercise, but this depends on your assessment findings.

When to get it checked

Many mild cases settle over a few weeks with activity modification and gentle exercise. It is worth booking an assessment if:

• the pain has lasted more than a few weeks or keeps coming back
• night pain is disturbing your sleep
• you are noticing weakness, or struggle to lift your arm at all
• the pain follows a fall or a sudden injury
• you have pins and needles or pain travelling down the arm

A physiotherapist can identify what is driving your pain, rule out other causes such as a rotator cuff tear, a frozen shoulder or a neck-related problem, and give you a clear plan. If you have private health insurance through Bupa, AXA or Vitality, you may be able to claim for your sessions, so it is worth checking your policy.

Seek urgent medical help if shoulder pain comes with chest pain, breathlessness, or a hot, swollen joint with fever, as these need prompt medical attention rather than physiotherapy.

A final word

Shoulder impingement feels worrying when you cannot lift your arm without a pinch, but the outlook is generally good once the underlying causes are addressed. The key is to keep the shoulder moving, load it gradually and work out what tipped it into irritation in the first place.

If your shoulder pain is persistent or affecting your work, training or sleep, you are welcome to book an assessment at our Vauxhall clinic. Our physiotherapy team will look at how your shoulder, upper back and neck are moving, explain what we find in plain English, and set out a plan that fits your life.