The shoulder joint is made up of the humerus (arm bone), clavicle (collarbone) and scapula (shoulder blade). The head of the humerus fits into the glenoid cavity of the scapula to form a ball-and-socket joint. The arm is then firmly kept together within this shallow socket by the rotator cuff, which is a complex group of muscles and tendons that team up to form a covering around the head of the humerus. The rotator cuff muscles which arise from the scapula and attach to the humeral head, provides strength and stability during shoulder motion.

The rotator cuff muscles, also known as the ‘SITS’ muscles are made up of the supraspinatus, infraspinatus, teres minor and subscapularis, respectively. The table shows the primary function of each rotator cuff muscle.

Between the rotator cuff and the acromion process of the scapula, is a lubricating, fluid-filled sac known as a bursa. The bursa covers and protects the muscles and tendons, keeping them from close contact with surrounding bones, thereby allowing the tendons to glide freely during arm movement. Thus, when the rotator cuff tendons become injured or damaged, this bursa may also become inflamed and painful.

Rotator cuff injuries are the most common cause of shoulder pain and disability among adults. This injury is common in patients over the age of 40, but can affect those who are younger too. They are also usually more common in males than in females. A rotator cuff strain is the over stretching or tearing of the rotator cuff tendon or muscle belly. The severity of the muscle strain depends on how much fibres were damaged, intensity of pain and the strength of muscle contraction.

There are two main causes of rotator cuff strain: acute traumatic and degenerative. Acute traumatic strains usually occur after a specific trauma such as, falling on an outstretched hand (FOOSH), or a single violent force or blow to the shoulder. Besides, prolonged or repetitive overuse of the rotator cuff over a short period of time – especially in athletes who repeatedly make overhead or forceful pulling motions are more prone to rotator cuff strain. Acute traumatic strains can also occur when overexerting during lifting or pulling something that is too heavy, or if a pre-existing shoulder impingement syndrome is already present.

Degenerative strains are as a result of the wear and tear of the rotator cuff tendon that occurs slowly over time, and it is usually painless. This type of strain is more common in the dominant arm, but if a degenerative strain is present in one arm, there is a higher likelihood of a rotator cuff strain in the opposite arm too, even if no pain is felt. It is usually associated with minimal trauma secondary to long-standing tendonitis or chronic impingement syndrome.

• Pain at the top and side of the shoulder.
• ‘Popping’ or tearing sound at the point of injury, followed by pain and weakness of the shoulder.
• Pain is worsened when leaning on elbow and shrugging the shoulder upwards.
• Unable to tolerate overhead motion.
• Pain that is present even at night, especially when weight-bearing on the affected shoulder.
• Gradual loss of range-of-motion on the affected shoulder if the injury has been persisting for a while, without treatment.
• Loss of strength in the shoulder.
• ‘Clicking’ or ‘snapping’ sounds (crepitus) during shoulder motion.
• Redness and swelling in the affected shoulder (in more severe cases).

A chiropractor would first take a detailed history to gain a better understanding of your condition. Next, a series of tests would be done during the physical examination to confirm the diagnosis, or rule it out. If the history and physical examination point towards a rotator cuff strain, it is also during this time that which of the four rotator cuff muscles are affected and the severity of injury has to be determined – it may be one or more rotator cuff muscle and findings may indicate a over stretch or a tear (partial or complete), respectively. Should there be any need for further investigation, referral for an MRI, X-ray or ultrasound imaging of the shoulder may be warranted.

For a stretched or partially torn muscle, conservative care can help improve pain, function and reduce disability. Modalities such as, therapeutic ultrasound, laser and interferential current therapies aid in reducing pain and swelling. Chiropractors also employ spinal manipulation of the neck and upper back to help ease the tension around the shoulder. These can take from 2 weeks up to 3 months to recover, and even more so depending on severity which can take up to a year of treatment to recover. For a completely torn muscle, surgical consult may be warranted instead.

The kidneys are a pair of bean-shaped organs on either side of the spine, located below the diaphragm, and behind the liver and stomach. The kidneys are responsible for filtering waste from blood plasma, thus keeping the body free from the toxic effects of fluid waste build up. They are also essential to maintain the levels of salt, pH and water in blood.

Due to their role in the removal of waste from the body, the kidneys can become susceptible to damage or infection. For example, when you do not drink enough water, calcium, oxalate, cystine or phosphate will start to accumulate, these minerals could crystallise and form stones, which usually presents as a severe sharp, stinging pain in the back. A deep, dull ache in the front, back or sides of the belly is a common presentation of kidney infection.

Meanwhile, bones, muscles and nerves make up the human back. Pain in the back can manifest in any part (cervical, thoracic, lumbar, sacral, pelvic) depending on where injury or damage has occurred. The kidneys rest against the back muscles, extending from the T12 to L3 vertebral levels, with the right kidney usually located slightly lower than the left due to presence of the liver. Therefore, it can be difficult to tell if the pain is originating from the lower back or the kidneys, or both. Due to the anatomical position of the kidneys and resemblance in presenting symptoms, kidney-related pain must be ruled out in patients with back pain, especially in the lower back. Nevertheless, back pain is extremely common hence, it is more likely that someone has back pain rather than kidney pain.

The causes of back pain are numerous. They can include mechanical causes such as muscle strains, ligamentous sprains, joint dysfunctions and disc herniations. These are usually due to overuse, poor posture or improper lifting techniques. For instance, a strained muscle can feel sharp and is worsened with movement. Nerve root pain in the lumbar spine can present as numbness and tingling sensations in the lower back that radiates into the lower limb. Pathological causes of back pain such as cancer, fracture and infection too can present as persisting pain that gets worse over time.

The main difference between lower back pain and kidney pain is that kidney pain tends to be experienced higher in the back (T12-L3 vertebral levels) compared to lower back pain (L1-L5 vertebral levels). Furthermore, kidney pain is usually persistent until it is resolved, while lower back pain can be relieved with conservative care.

The table below may act as a quick-reference guide for you to determine if you are more likely to have back pain or kidney pain:

Given that kidney pain can sometimes be confused with back pain, it is not uncommon for chiropractors to see patients having either types of pain, or both. A detailed history would be taken and a physical examination with suitable tests would be done to determine the nature of the pain. Should there be any further need for investigation, the chiropractor can also order a complete blood count (CBC) and urinalysis to assess the function of your organs. If any problems are detected with kidney function on the laboratory result, then a prompt referral to a specialist is warranted.