One of the more common diagnoses I see in my clinic is shoulder pain- or also called shoulder impingement. I have a lot of fun treating these individuals because it is usually successful with physical therapy. There is even evidence that shows physical therapy can be as effective as surgery in most cases (Saltychev et al, 2013). I am going to be discussing the basics of this condition, but there are a lot of details and scenarios that I will not touch on today. This is not meant to replace medical advice, only to provide information regarding the shoulder. If you have pain, you should contact your doctor.
What is Shoulder Impingement?:
Shoulder impingement usually refers to pain in this region:
This type of pain is usually described as achy at rest or with light activities, but it can be sharp with certain movements. Usually there is a pinch or sharp pain where the “x” is in the above picture and more aching/soreness in the red region.
Movements of the Shoulder:
The shoulder is a ball and socket joint that moves in many directions (or planes of movement):
The Shoulder Joint
The Bones of the Shoulder Joint
I want to start by breaking down the shoulder joint and the bones of the shoulder and how various muscles are attached so you can get the full picture. It helps to visualize the shoulder and muscles so that when you have pain you can understand what may be causing it.
Shoulder: The shoulder joint is a ball and socket joint. The ball is made up of the head of the humerus (bone of the upper arm) and the socket is the glenoid of the scapula (shoulder blade). Because it is a ball and socket joint, it has a lot of movement and relies on tendons, muscles, and ligaments to give it more support.
The shoulder blade (scapula): The scapula is a bone that moves freely. It lies on your back on top of the rib cage. It has a bony projection that attaches to the collar bone (clavicle). It also contains the glenoid (socket) for the shoulder joint. A lot of muscles attach to the scapula. The image below is of a left scapula. The flat surface lies on the rib cage. From the side view you can see the glenoid (socket).
Acromioclavicular Joint (AC Joint): The AC joint is where a bony extension from the scapula connects with the clavicle (collar bone). It is a non-moving joint that is connected through a ligament. This joint creates a tunnel called the subacromial space (described below).
Subacromial Space: This is a space that contains the supraspinatus tendon, a biceps tendon, and a bursa (a fluid filled sac that protects tendon). This space is created by the AC joint and the humeral head (ball of the ball and socket joint). This space is approximately 9-10mm (Petersson and Redlund-Johnell, 1984), and the supraspinatus tendon is approximately 6.6mm (Bjordal et al 2003). Essentially this means there is 2.4-3.4mm of space for movement and the other structures in this area. There is not a lot of room for error. In the second picture you can see how the bursa and tendon can get pinched under the AC joint. This can happen for a variety of reasons, some of which will be discussed below.
The Muscles of the Shoulder Joint:
The Rotator Cuff: Comprised of 4 muscles- infraspinatus, supraspinatus, subscapularis, and the teres minor. These muscles support the shoulder joint and help to keep the ball in the socket. They perform abduction, internal rotation, and external rotation (refer to above for what these motions are). There are other muscles that assist these motions, however there may be weakness in one or more of these muscles if you have shoulder pain. Most commonly pain is in the supraspinatus muscle.
Upper, Middle, and Lower Trapezius: The trapezius (trap) is actually one big muscle that has 3 parts. It can affect the neck, scapula, spine, and shoulder because of all its connections. This muscle plays a very important roll as it relates to the shoulder. When someone lifts their arm over their head, these muscles rotate the scapula to give you more range of motion. Normally a person can raise their hand about 180 degrees over their head. 120 of these degrees comes from the ball and socket shoulder joint. The other 60 degrees comes from the scapula rotating which will lift the AC joint and give room for more motion. See the animation below to see how this looks. If there is a deficit in this muscle group (whether it is weakness or coordination problems) it can lead to the pinching of the shoulder as shown in a picture above (under subacromial space).
There are quite a few things that can go wrong with the shoulder, however the most common non-traumatic diagnosis is shoulder impingement.
Symptoms of Shoulder Impingement:
- Pain with arm reaching overhead, especially in the mid-range and end range
- Pain with reaching across the body towards your opposite shoulder blade
- Pain with reaching up behind your back (toward bra level)
- Pain with reaching far out in front of your body
- Pain with turning the steering wheel
- Potential loss of flexibility (can’t reach as high or up behind your back as high)
- Pain with lifting, especially when holding an object away from the body
- Pain with weight bearing on the arm
- Clicking/popping more than usual
- Sometimes the pain feels better after some light activity (i.e. walking, running, stretching)
- Sometimes pain may be greater in the morning
- There also may be pain with athletes who serve overhead or throw
Causes of Shoulder Impingement:
Shoulder impingement can have many causes. Most commonly it is due to the supraspinatus tendon or bursa getting frequently pinched against the AC joint, causing irritation. Remember that the bursa and supraspinatus tendon lie within the subacromial space. Just to refresh your memory: the subacromial space is about 9-10mm and contains one tendon of the biceps, a bursa, and the supraspinatus tendon (about 6.6mm), meaning there is a lot going on in a small space. The following are various things that can lead to this type of shoulder pain. Keep in mind that it can be a combination of the following or something entirely different that is not stated below:
- Sleeping position: We want to avoid any sleeping position that can lead to pinching of the structures in the subacromial space. If you are lying on your painful shoulder, you are going to be pinching those structures over a long period of time. However lying on your opposite side may cause problems as well because your painful shoulder will fall forward with gravity and pinching will occur. Proper sleeping position will be addressed below.
- Poor mechanics with overhead activities: Remember that trap muscles we discussed earlier? If you tend to have a dominate upper trap and a less dominate lower trap you may shrug up your shoulders with reaching and lifting mechanics. This decreases the amount of room in your subacromial space. Additionally your shoulders might round forward which can further decrease the space, leading to pinching.
- Muscle imbalances: This goes along with mechanics. You need to use your middle and lower traps to assist with lifting and reaching to prevent excessive pinching in the subacromial space. If these muscles are weak, you will most likely compensate with other musculature, leading to poor mechanics and overuse.
- Rotator cuff weakness: If there is weakness in the rotator cuff, your shoulder will have less stability. This means extra motion that can lead to more pinching.
- Limited flexibility: If you have pec tightness it will pull your shoulder forwards which will decrease the subacromial space. The back of the shoulder joint may also be tight which could also push the ball of the shoulder joint forwards leading to more pinching.
- Middle and upper back stiffness: We need good middle and upper back flexibility for good shoulder mobility. If there is tightness, the shoulder joint will be pushed forwards causing more pinching. We also move slightly through our back with reaching overhead but if there is tightness we will have to move excessively in our shoulder to compensate.
Treatments for Shoulder Impingement
Below I have listed quite a few exercises that we use in physical therapy to address all potential causes of shoulder pain. In physical therapy, not all individuals are given the same exercises because each person may have different causes for their pain. There are a variety of exercises listed below of different difficulty levels. It is important to remember that these exercises are not to be done if they are painful. You should see your doctor prior to trying any of these exercises and seeing a professional is the best way to address shoulder pain.
Sleeping position: If your are not able to sleep on your back comfortably, try this sleeping position to support your arm. Lie on your non-painful side with your painful side being fully supported by a pillow.
Posture: Avoid sitting or standing with your head forwards and your shoulders rounded. We want to keep our ears, shoulders, and hips all in the same line.
Mechanics with lifting/reaching: We want to avoid shrugging up our shoulders with all of these exercises as well as with reaching and lifting activities we do during the day. The first video is what shrugging looks like and the second video is correct mechanics. A good way to think of this is think of putting your shoulder blades into your back pockets (down and back).
Sleeper stretch: Lying on your painful side, put your elbow in line with your shoulder and bend your elbow 90 degrees. Push your hand (palm down) towards the bed using your opposite hand. When you feel a stretch in the top or back of the shoulder, hold 30 seconds. Repeat 3 times. Make sure it is a stretch and NOT PAIN.
Pec Stretch: Find an empty corner or doorway to perform this in. Place your entire forearm against the walls (fingers to elbow) with your elbows above your shoulder height. Place one foot in front of the other, and lean into the corner or doorway. You should feel a stretch across your chest and/or front of shoulder. Hold 30 seconds. Repeat 3 times.
Tennis Ball Upper Trap Release: Find an empty corner, doorway, or table leg. Place the tennis ball at the meat of your muscle close to your neck. Using your feet on the ground, push your body into the ball and hold this position. Tilt your head away from the tennis ball. You should feel a big stretch in your neck and maybe even your head on the side with the tennis ball. Hold 30 seconds and repeat 3 times.
Upper and Middle Back Stretch with Foam Roller: Using a foam roller horizontally, place your hands behind your head to protect your neck and lean over the foam roller. You should feel a stretch in the middle back. You can roll the foam roller to cover all the vertebrae of the middle back but do not do the lower back or the neck (stick to areas that have ribs). DO NOT PERFORM THIS IF: you have osteoporosis, hypermobility diseases, spinal fractures, rib fractures, or other back problems. Get cleared from a medical professional before attempting.
Prayer Pose 3 Ways: This is a good upper back and lat stretch. Perform centered and to the right and left to maximize its benefit. Hold 30 seconds repeating 3 times each way.
Is, Ts, Ys: The primary goal of this exercise is to strengthen the muscles between your shoulder blades. Start by squeezing your shoulder blades together and down (as if to put them in your back pockets), and then lift your arms a few inches off the ground. Do not lift them higher than your body. Perform 3 sets of 10-20 reps of each movement.
Ys with pull down: This is a little bit harder than the above stated exercise. Holding onto a stick, golf club, or weight bar, squeeze your shoulder blades down and back and lift your arms so that the stick clears your head. Slowly bring the stick towards your shoulders without letting it touch your body. Return to starting position. Perform 3 sets of 10-20 reps.
Planks: The first picture is a modified plank and the second picture is a full plank. Make sure you keep your entire back flat and shoulder blades squeezed down and back. Hold 10-30 seconds repeat 5-10 times. You should only feel muscle fatigue in your arms, legs, and core but NOT in your lower back. Don’t do this unless you have been medically cleared by a doctor.
External rotation in sidelying: Lying on your non-painful side, have the painful arm resting on your side with the elbow bent to 90 degrees. Squeeze your shoulder blade back and down. Keeping your shoulder blade squeezed, rotate your painful arm up towards the ceiling. Do not push for quantity of range, and make sure it is pain free. Start unweighted and then progress 1-5# as able. Do 3 sets of 10-20 reps.
Internal Rotation at 0 and 90 degrees: With your painful side holding the band and the band attached to a door handle (or fastened to a stable object), have your elbow bent to 90 degrees and squeeze your shoulder blade down and back. Rotate your shoulder so that your hand is moving towards your stomach. Perform 3 sets of 10-20 reps. For a more advanced option, elevate your arm so that your shoulder and elbow are in line with each other and maintain elbow flexion at 90 degrees.
External Rotation at 0 and 90 degrees: With your painful side holding the band and the band attached to a door handle (or fastened to a stable object), have your elbow bent to 90 degrees and squeeze your shoulder blade down and back. Rotate your shoulder so that your hand is moving away from your stomach. Perform 3 sets of 10-20 reps. For a more advanced option, elevate your arm so that your shoulder and elbow are in line with each other and maintain elbow flexion at 90 degrees.
Scaption: Starting without any weights, squeeze your shoulder blades down and back and elevate your arms to shoulder height. This should be performed with arms wider than shoulder with but staying in front of the body. You can progress 1-5# ensuring it is pain free. Do 3 sets of 10-20 reps.
I hope you found this informative and helpful. I want to reiterate that this should not replace medical advice or treatment. If you have consistent shoulder pain that has not improved, you should see your doctor and may benefit from seeing a physical therapist.
Stay healthy my friends!
-Katie PT, DPT