Rotator Cuff Anatomy
Rotator cuff tears are among the most common shoulder injuries that people suffer. Each year, 2 million people see a physician for a rotator cuff injury in the United States according to the American Academy of Orthopaedic Surgeons. It is important to understand exactly what comprises the rotator cuff and how it becomes torn.
The above image shows the back of the shoulder including three out of four rotator cuff muscles. Overall, the rotator cuff secures the head of the humerus in the shoulder joint and helps maintain the joint stability with movement. The four rotator cuff muscles come together to aid the labrum of the shoulder in securing the humerus. The shoulder is the most mobile joint in the body and it relies on muscular support more than any other joint. The rotator cuff muscles are the most important muscles in terms of shoulder joint support.
As I mentioned, the main purpose of the rotator cuff muscles is to support the shoulder, but they all have other functions as well. The supraspinatus primarily helps elevate the arm as you go overhead. The infraspinatus and teres minor help with external rotation, while the subscapularis creates internal rotation.
The most common muscle to be injured is the supraspinatus based on its use with any sort of shoulder elevation. It is also in a difficult position due to the anatomy around it compressing the tendon. This is especially worsened as we age, when we lose blood flow and gain bone spurs in the shoulder joint.
The nature of the tear is also an important component of understanding injury. Partial tears involve damage to the muscle or tendon that does not go all the way through the structure. Full thickness tears pierce the entire tendon. Obviously a full thickness tear typically results in worse symptoms, but that is not always the case. Oftentimes, rotator cuff tears are asymptomatic, particularly in older adults or those who repeatedly work overhead such as baseball players or manual laborers.
Rotator Cuff Tear Symptoms
Rotator cuff tears typically occur traumatically from a fall or from chronic wear and tear. Most commonly, if you slip and fall on an outstretched hand, the force can create too much stress for the rotator cuff to handle. Chronic stress from overhead athletics or labor can lead to a rotator cuff tear overtime. In these cases there is often not a single inciting incident, but you may notice a gradual onset of symptoms.
The primary symptom of a rotator cuff tear is pain with overhead movements. Pain is a primary motivator to seek treatment, as you can often compensate for mobility or strength limitations. Initially, pain may only occur with overhead movements or heavy lifting. As symptoms worsen, pain may be felt with less movement and less load. Eventually pain can be felt at rest. A common irritating position is lying on the affected shoulder, especially when sleeping.
Weakness is also a common symptom due to the damage to the muscle. The exact weakness depends on the injured muscle, but the rotator cuff is responsible for shoulder stability. Any rotator cuff tear has potential to decrease overhead strength due to the increased stress on the shoulder.
Mobility can be limited due to poor stabilization of the shoulder. If there is pain or weakness of the shoulder, then you are less likely to use it in its full range. Over time, this can lead to tightness of the muscles and an inability to achieve full range of motion.
Rotator Cuff Tear Test and Diagnosis
Diagnosis of a rotator cuff tear depends on several factors. A thorough history should provide information regarding a possible cause of the tear. Rotator cuff tears are one of the most common shoulder injuries, so healthcare providers are typically aware of the injury.
There are many special tests for the shoulder, but a cluster of three tests is deemed the most accurate to diagnose a rotator cuff tear.
The first test is known as the Drop Arm Test. The practitioner will lift your arm to 90 degrees at your side. They will then let go of the arm and have you slowly lower it down. If you are unable to control the arm then you fail the test.
The second test is the manual muscle test for the infraspinatus muscle. External rotation is the action of the infraspinatus and teres minor. It is also a stressful movement for all of the rotator cuff muscles. The test is pictured below courtesy of researchgate.net
The final test is the Painful Arc Test. You will raise your arms as high as you can at your side and note any pain. There is typically a painful arc from 60 to 120 degrees as shown below courtesy of alamy.com. 60 to 120 degrees is the range that most relies on the rotator cuff to stabilize the humeral head to allow for pain-free mobility.
Diagnosis by x-ray is not typical as the imaging will not show muscles. Sometimes bone spurs can be observed by x-ray which leads to increased likelihood of a rotator cuff tear. However, an MRI is necessary to definitively diagnose a rotator cuff tear. The MRI will also allow the provider to determine which muscle is torn and the extent of the tear.
Rotator Cuff Tear Rehab
Treatment for a rotator cuff tear should aim to maintain as much mobility as possible even if that is done passively. Any lost range of motion can take a long time to regain, so it is important to keep moving even if the motion is painful. Frozen shoulder is a possibility with any shoulder injury that causes prolonged immobility. Recovery from a frozen shoulder can take multiple years, so it is important to avoid it at all costs.
Rotator cuff tear rehabilitation should determine what movements are limited based on the muscle tear and physical exam. The exercises should be tailored to address that movement limitation. For example, if you have difficulty reaching behind your back, then it is important to break that movement down into shoulder extension and internal rotation to find where you are truly limited. Individualized care is crucial for a rotator cuff tear.
A shoulder shrug sign is common with rotator cuff tears. The image above courtesy of championpatandperformance.com shows a classic example. The reason for this movement is the lack of stability in the shoulder joint forces increased activation of the upper trapezius and levator scapula to elevated the scapula. If the shoulder itself is unable to reach overhead, then you will instinctively elevate the shoulder to artificially gain more movement. It is important to decrease the shoulder shrug as the rotator cuff becomes strong enough to create elevation on its own.
Rotator Cuff Tear Exercises
The initial exercises in physical therapy should include mobility work as tolerated. The lat pulldown machine is an excellent tool to improve elevation passively while strengthening as you pull down. If it is too painful, then simple stick mobility into limited ranges can be effective. As I mentioned before, mobility is crucial.
Isometrics are an excellent starting point for strengthening and muscle engagement. Promoting blood flow to the injured rotator cuff can enhance healing and recovery. Simply pushing into a wall in limited directions can be effective. Also, a push up position is a good starting point as it is not a typically provocative range of motion and it can be progressed easily.
If you are trying to decrease upper trapezius and levator scapula activity, then increasing strength of the serratus anterior can be helpful. The serratus anterior counteracts the overactive muscles and promotes scapular mobility. More movement from the scapula can decrease stress on the healing rotator cuff. The wall slides pictured below courtesy of skible.com are an excellent starting point to enhance mobility and feel proper scapular mechanics.
Lateral raises are an excellent strengthening exercise to promote rotator cuff strength as you progress to overhead movements. This exercise also strengthens the deltoid which is crucial to support the rotator cuff. Keeping the range of motion around 90 degrees is typically tolerated. If there is pain then turning the thumbs upward and moving the arms slightly forward can decrease stress on the shoulder.
External rotation is an important movement functionally to improve overhead strength. It is also crucial to building rotator cuff strength. Utilizing bands or dumbbells can provide adequate load to strengthen the rotator cuff muscles as tolerated.
The final movement that should be performed is an overhead press. Strengthening this range of motion will improve mobility as well as strength. This movement stresses the rotator cuff to stabilize the head of the humerus in a vulnerable position. It is important to train these movements in physical therapy before attempting them at the gym or in daily activities. You can start with a seated overhead press in an inclined position and gradually increase the angle until you are sitting upright or standing.
As always, if you are suffering from pain, nerve symptoms (numbness, tingling, or weakness), or anything else significant, please see a healthcare provider. This blog is meant to be educational and is not a substitute for medical advice.
Hopefully you learned something about rotator cuff tears and how they are diagnosed, what symptoms are typically felt, what treatment options are a possibility, and how physical therapy typically progresses. If you have interest in other shoulder injuries, check out our shoulder page. If you found this blog helpful, please share it with someone. We hope to continue to grow and help people better understand how our bodies move and work. If you are in the Sterling, Virginia area and would like to work with me or you have any questions, please email me at danny@eclipsewellnessnova.com or follow me on Instagram or Twitter @drdannydpt.
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