Shoulder injuries can be caused by a myriad of reasons, ranging from athletic activities to everyday tasks. This may include overhead movements that involve repetitive motions found in sports such as weightlifting, swimming, and a host of racquet sports. Everyday tasks such as household chores, plumbing, or gardening can similarly expose you to the risk of overuse shoulder injuries.
Additionally, shoulder injuries can arise from accidents that inflict trauma upon your shoulder joint. You may experience broken bones or soft tissue damage, and in some cases, a combination of both.
But this doesn’t mean you should avoid sporting or outdoor activities. In fact, you should seek out injury prevention strategies that can help minimise your risk of injury.
To understand the different types of shoulder injuries, we first have to examine the shoulder joint to understand how injuries can occur. You should know that the shoulder is the most mobile joint in the human body, consisting of numerous muscles and tendons which hold the shoulder bones in place. These ligaments are also responsible for stabilising arm movement.
To obtain a better picture, let’s take a closer look at the shoulder.
Firstly, the bursa is a gel-filled sac that sits across the shoulder joint, providing protection for the surrounding tendons and muscles. When the bursa in the shoulder becomes inflamed, it can cause a great deal of pain. Shoulder impingement syndrome or rotator cuff problems may also arise from bursitis.
Secondly, the shoulder is a ball and socket joint whose wide surface area predisposes itself to the possibility of injury. Prolonged trauma exerted on the shoulder can lead to the formation of scar tissue. Other various dysfunctions in movement patterns may also develop over time. There are also degenerative conditions, such as arthritis, which arise due to wear and tear of the joint.
Thirdly, the shoulder joint itself contains a piece of cartilage known as the labrum. The labrum can become torn or strained during impact injuries, which affects the shoulder’s full range of motion. Shoulder dislocations, for example, can result in labral tears that require reconstructive surgery.
Fourthly, the tendons connecting the bicep and deltoid can also experience tendonitis, leading to joint pain.
Lastly, ligament tears or strains may also occur within the acromioclavicular joint (AC joint) due to traumatic injuries.
One thing to note is that most sports place physical demands on the shoulder joint, which is susceptible to injury owing to its remarkable mobility. The shoulder structure itself is not as stable as joints in the legs and hips, making the shoulder much more vulnerable to injury. As mentioned earlier, this shouldn’t scare you away from your favourite sporting activities.
Nevertheless, it is important to understand how these injuries come about. Read on to find out more…
A dislocated shoulder occurs when the upper arm bone is displaced from the cup-shaped socket of your shoulder joint. This injury is common given that the shoulder is the most mobile joint in the body. Unlike other joints, it is more susceptible to dislocation.
Note that a shoulder subluxation, which happens when the shoulder dislocates partially but immediately goes back into the socket, is a type of dislocation.
Shoulder dislocations can either be anterior or posterior. For the vast majority of cases, dislocated shoulders arise due to trauma from direct force or impact on the shoulder. In some cases, patients may also experience a sudden forceful movement that destabilises and overwhelms the joint, leading to dislocation.
This can occur in contact sports such as American football, rugby, basketball, soccer, and water polo due to trauma inflicted from a collision. It can also happen from an accident where there is a forceful and direct impact on the shoulder, such as tripping and falling from a ladder.
Anterior dislocations make up 97% of shoulder dislocations. However, the shoulder may not always fully dislocate. In some cases, you may experience a partial dislocation, known as a shoulder subluxation. This occurs when the head of the upper arm bone only partly disconnects and pops back into the socket by itself.
The symptoms for a dislocated shoulder include:
The rotator cuff is made up of a group of muscles and tendons which help to stabilise the shoulder joint, supporting regular movement function. Pressing and pulling movements, for example, involve the use of the rotator cuff to stabilise and move the joint.
The common types of rotator cuff injuries include tendinitis, bursitis, rotator cuff strains, and rotator cuff tears.
Not all rotator cuff injuries are equal, as some may be more severe than others. They generally fall into one of three categories.
Rotator cuff strains (less severe) or rotator cuff tears (more severe) can be caused by two reasons: overuse injury over time or the sudden onset of acute injury. When this happens, the tendons connecting the shoulder muscles to the shoulder blade can overstretch and become strained or torn, resulting in sharp pain.
Tendinitis is a type of rotator cuff injury caused by overuse of the rotator cuff, leading to inflammation and pain in the shoulder. Racquet sports and activities such as weightlifting which require overhead movements can cause this injury.
Another common type of rotator cuff injury is bursitis, which is caused by repetitive motions such as a pitcher throwing a baseball over and over. Spending an extended period of time in uncomfortable positions that put pressure on your shoulder can also cause bursitis.
Common rotator cuff injury symptoms include:
It is important to note that not all rotator cuff injuries cause pain, as some are the result of long-term degenerative conditions that may not be apparent until years later.
Unlike other shoulder injuries that occur from an immediate traumatic sports accident, shoulder impingement syndrome usually develops over a period of time. It is also commonly referred to as shoulder tendinitis.
Shoulder impingement syndrome is one of the most common culprits of persistent shoulder pain, and can greatly affect everyday activities. Even simple tasks such as reaching to scratch your back or reaching overhead to close the curtains can be a cause of pain.
Over time, if left untreated, the shoulder joint may slowly worsen and the tendons may begin to thin or even tear.
Most cases of shoulder impingement are caused by overuse. This is common among sports athletes and powerlifters, as repeated use of the shoulder in the gym can result in the shoulder tendons swelling. Other sports which require heavy lifting or repetitive overhead arm movement can similarly cause shoulder impingement over time.
Occupations such as construction work, warehouse packing, and painting can also predispose workers to shoulder impingement. Initially, the pain you experience may not be significant enough to warrant attention. However, it will gradually worsen over time if left unchecked.
The symptoms include:
Frozen shoulder is a condition characterised by stiffness and pain in your shoulder joint, resulting in a reduced range of motion. In some extreme cases, the shoulder becomes increasingly difficult to move, almost as if it has become ‘frozen’. It is also known as adhesive capsulitis.
The good news is that frozen shoulder is one condition that tends to heal by itself over a long period of time. However, physical therapy and rehabilitation exercises will help to speed up the recovery process and improve overall shoulder health.
Doctors and medical researchers do not fully understand the causes of frozen shoulder. More accurately, there has been no established connection between overuse of a dominant arm or a specific occupation which predisposes you towards developing a frozen shoulder. However, there are a few factors that may increase your risk of developing the condition.
For one, frozen shoulder occurs more frequently in patients diagnosed with diabetes. The exact reason for this is unknown, but diabetic patients who develop frozen shoulder usually tend to experience greater stiffness that persists for a longer period of time. Several other diseases have also been associated with the increased likelihood of developing frozen shoulder. They include hyperthyroidism, hypothyroidism, cardiovascular disease, Tuberculosis, and Parkinson’s disease.
Another cause is long-term immobilisation of the shoulder due to recovery from surgery, fracture, or soft tissue injury. If you have experienced prolonged immobility, such as having your arm kept in a cast, you will be at a higher risk of developing a frozen shoulder.
The symptoms include:
Frozen shoulder typically develops in three stages, with each lasting as long as a couple of months. The first is the freezing stage, where the pain is first experienced. The second is the frozen stage, where your shoulder becomes stiffer. The third is the thawing stage when your shoulder joint’s range of motion slowly becomes restored.
Fractures are essentially broken bones. Shoulder fractures occur as a result of trauma to the shoulder joint.
The types of shoulder fractures include:
In cases such as traumatic accidents from contact sports, a shoulder can suffer both broken bones and soft-tissue damage. For example, a fracture on top of a torn ligament.
The most common cause of a shoulder fracture is a fall which results in trauma being inflicted directly onto the shoulder. Collisions from contact sports or road accidents can also cause shoulder fractures.
The symptoms include:
A shoulder contusion, also known as a shoulder bruise, is a mild shoulder injury that can arise due to a direct blow to the shoulder joint.
Although a shoulder contusion can be the cause of temporary discomfort, it’s an injury that usually goes away by itself. As long as you don’t have any broken bones, this injury will take anywhere from a few days to a few weeks to heal. In more severe cases, shoulder contusions might be treated with a sling to immobilise the arm.
Shoulder contusions happen when a direct blow or repeated blows strike the shoulder area, damaging the muscle fibres and connective tissue under the surface of the skin. Contusions are most typically the result of sports-related injuries, especially in sports such as American football, rugby, basketball, lacrosse, basketball, and baseball.
The symptoms include:
Given the prevalence of shoulder injuries, it can be incredibly frustrating for athletes and those who lead a physically active lifestyle. Unfortunately, shoulders that have been injured before are more likely to become injured again.
For this reason, it is important to identify small pains and aches instead of ignoring them until they become a problem. You have to recognise that pain is your body’s indication that something is wrong, possibly due to bad form, muscle tightness, strength imbalance, amongst other problems.
Beyond that, it is also paramount to preemptively lower your risk of injury through certain injury prevention techniques. The emphasis here is to take proactive steps to prevent injury before it can happen, focusing on prehab rather than just rehab work.
If done right, you should be able to improve your overall shoulder health, thereby minimising the likelihood of injury.
The targeted shoulder strength training referred to in this section is not your regular full-body strength training. Rather, it is specifically targeted at the muscles which are responsible for keeping your shoulder joint stable.
The important muscle groups that you should target include:
Most of the shoulder joint’s stability and movement is dependent on the small rotator cuff muscles which surround the shoulder joint. While compound exercises in the gym provide many strength benefits, they fail to provide adequate activation of the smaller stabiliser muscles. In other words, exercises like the barbell row will work the trapezius and rhomboids significantly but do not do a good job of activating the supraspinatus and infraspinatus muscles.
It is important not to neglect the small stabiliser muscles in the shoulder joint, as they are essential in preventing injuries. Exercises that target these areas have been incorporated into physical therapy programs, which are also often used for rehabilitation after injuries. This is because the key to keeping your shoulder strong and flexible is with exercises that target these small yet important muscles.
Examples of exercises that target the stabiliser muscles include:
Having poor posture may seem harmless, but did you know that poor posture can lead to shoulder instability? In fact, poor posture can lead to many shoulder problems such as shoulder impingement.
For athletes and gym-goers, in particular, poor posture is often exacerbated by muscle imbalances due to a greater emphasis placed on pressing movements such as the bench press and overhead press. When back development is neglected, this can become problematic.
Fitness enthusiasts should therefore aim to have a balanced push/pull training program, thus preventing muscular imbalances from developing. What we often see in most athletes is the over-emphasis on pressing movements while neglecting pulling movements, which commonly results in internally rotated shoulders, also known as rounded shoulders.
Rounded shoulders are one of the most common postural alignment problems that people suffer from. Not only do they look unsightly, but they also put our shoulder joints at risk. Rounded shoulders, if left untreated, can also get worse over time. Consequently, bad postural habits will also influence your movement, which in turn poses a higher risk of a shoulder injury.
For that reason, it is crucial to resolve the imbalance of tension between the muscles which pull your shoulder blades forward and the muscles that pull your shoulder blades backwards. Having good posture will go a long way when it comes to shoulder injury prevention.
Most people underestimate the importance of good flexibility and mobility without realising how greatly they can reduce the risk of experiencing shoulder injuries. But first, you should know that they are two different things; flexibility is the ability of a muscle to lengthen passively while mobility is the ability of a joint to move through a range of motion.
When it comes to shoulder injury prevention, optimising your shoulder joint’s flexibility can help the ball of the shoulder joint stay centred throughout the entire range of motion for an arm swing. If the shoulder capsule is tight and lacks mobility, a sudden movement that sends your arm reaching overhead could result in injury. Although tightness in the tendons surrounding the shoulder joint may seem harmless, they ultimately contribute to the micro-instability of the joint.
In particular, there are two areas of the shoulder joint in which reduced flexibility and mobility can be particularly problematic. The first is the humerus, which is meant to freely move about the shoulder socket. If you suffer from shoulder mobility issues, this will impede the range of flexion, extension, internal rotation, and external rotation movement. The second is the rotator cuff, which requires flexibility of the rotator cuff muscles for freedom of movement.
In essence, having good flexibility and mobility are important for achieving a healthy range of motion at the shoulder joint. Beyond just preventing injuries, having good shoulder mobility will also carry over to greater performance in the gym or out in the field.
Strengthening your stabiliser muscles and improving your postural alignment can provide a good foundation for avoiding shoulder injuries, but mobility exercises and static stretches can sometimes be insufficient for releasing tightness in the shoulder.
Here is where self-myofascial release (SMR) techniques come in. Myofascial release can help to effectively release tension in the muscles surrounding the shoulder joint. For the longest time, it was thought that static stretching of each individual muscle group post-exercise was the best strategy. But recent medical research has identified new techniques and approaches to physiotherapy, rebuilding the whole concept of mobility training.
When it comes to SMR or soft tissue work, your goal is simply to relax or “wind-down” certain muscle groups that are overactive or unnecessarily restrictive. This involves the use of foam rollers as well as lacrosse balls and applying deep, slow, and consistent pressure. These techniques can be immensely helpful for resolving shoulder mobility issues and impaired movements. Furthermore, they also help to alleviate pain due to tight muscles and fascia.
Overall, SMR techniques are designed to relieve knots, stiffness, and pain. This not only helps to prevent tightness but also restores your full range of motion, thereby reducing the risk of injury when playing sports. This is particularly useful to athletes who are experiencing slight pain or discomfort, as soft tissue work will help to clear up mobility problems in their shoulders which may otherwise lead to impaired movement and eventual injury.
The first step towards shoulder injury prevention is to simply get started. Now that you’re aware of the different strategies which can help lower your risk of injury, you should make improving your overall shoulder health a priority. Even small habits such as practising good posture or stretching daily can go a long way.
Do not be discouraged if you take some time to see progress because good mobility and flexibility do not happen overnight. In all likelihood, it took you many years of poor posture for your shoulder health to deteriorate to where it is now. Similarly, it will take some degree of effort to restore your natural postural alignment and a full range of motion.
Until then, enjoy the process of bulletproofing your shoulders.
Dr. Ong Kee Leong
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Senior Consultant, MBBS (Singapore), MMed (Ortho), FRCSEd (Ortho)
Dr. Ong Kee Leong is a fellowship-trained orthopaedic surgeon. He subspecializes in shoulder and knee, foot and ankle, hand wrist and elbow surgeries, arthroscopic sports surgery, and the management of sports-related injuries.
He has been registered with the Singapore Medical Council as a specialist in Orthopaedic Surgery since 2011.
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