SHOULDER PAIN
Rotator Cuff Tendonitis or Impingement Syndrome is one of the most frequent
causes of shoulder pain. Depending on the level of dysfunction, one may
experience symptoms such as difficulty in lifting the arm above 90 °, pain
reaching into the backseat or removing shirts overhead, and aching while
sleeping on the affected shoulder. It often begins with a mild pain but can
quickly become excruciating. If left unattended it can become permanent.
However, full recovery can be realized if it is correctly diagnosed and treated
at an early stage. Shoulder tendonitis typically arises among people performing
repetitive overhead actions such as swimmers, weightlifters and tennis players,
or those required to sustain elevated arm positions, such as an electricians,
painters or drywallers. It is seen in sedentary individuals as well.
Regardless of the activity that seemed to be the cause, all individuals suffer
from a muscle imbalance, altered recruitment patterns of stabilizing muscles
and poor proprioception of the shoulder joint.
Causes of Shoulder Tendonitis
The anatomy of the shoulder joint allows a freedom of movement not seen in
other joints; however this is traded off for poorer stability of the joint.
Shoulders are an intricate arrangement of bones, ligaments, muscles and
rotator cuff tendons. Each structure plays an important role in maintaining the
strength and stability of your shoulder. There are four rotator cuff muscles
located on the shoulder blade, attaching to the top of the arm bone, the
humerous and run underneath the tip of the shoulder, the acromion. The
rotator cuff tendons are protected by the bursa. The rotator cuff tendons keep
the shoulders stable, by pulling the humerous into the socket. Under usual
circumstances, rotator cuff tendons pass fluidly between the humerus and the
acromion. However, when the biomechanics are altered, the shoulder blade
doesn’t rotate upwards and the humerous migrates up, causing insufficient
clearance for the tendons. The tendons then get pinched between the 2 bones,
become inflamed and cause immense pain in the shoulder region.
Proprioception is the body’s ability to determine where it is in space, it is also
responsible for balance. There are receptors within our joints, skin, muscles,
tendons and ligaments which work together to convey information to the brain
about the location of each specific joint. The brain then sends corrective
information to specific muscle groups to modify a position or contract a
muscle. Poor proprioception leads to changes in muscle reflexes and muscle
activation patterns, likely increasing the risk of injury.
Injuries to shoulders
Repetitive overhead motion of the shoulder may cause fatigue and impaired
firing patterns around the shoulder blade, which increases the risk of rotator
cuff tendonitis. Athletes participating in activities such as swimming or weight
lifting, where there is resistance on the rotator cuff muscles have to be
particularly careful that their technique is correct in order to prevent injury.
Sustained postures with the shoulder elevated over 90° impairs the blood
supply to the supraspinatus tendon, thus the shoulder is more susceptible to
injury with sustained overhead shoulder positions. Electricians, painters,
drywallers who frequently work with their arms elevated are at greater risk for
impingement. Sedentary individuals tend to develop a weakness in the
stabilizing muscles of the shoulder blade and tightness in the chest muscles,
resulting in the shoulders becoming rounded through the back and the arm
being pulled forward. Both of these positions decrease the space in the
shoulder for the rotator cuff tendons to pass through. This is exemplified by
poor posture, often found in those spending long hours in front of a computer
(especially a laptop), or driving. Poor proprioception results from inactivity,
contributing to the muscle imbalance and altered firing pattern of stabilizing
muscles.
Strategies for treating shoulder tendonitis
The goals of treatment for rotator cuff tendonitis are firstly to decrease
inflammation of the tendons and reduce the pain. These go hand in hand, as
inflammation is a major contributor to pain by sensitizing the nerve endings
and sending pain signals to the brain. Avoiding aggravating activities and
resting the joint allows the rotator cuff tendons to start the healing process.
Ice, acupuncture and ultrasound are used to help diminish inflammation.
Secondly, proper biomechanics must be restored by correcting the muscle
activation of the shoulder blade muscles and rotator cuff muscles. Manual
therapy to the shoulder, neck and upper back help improve the mobility of the
affected joints. With a therapist manually assisting the joints to move correctly
the body relearns what it needs to do; this is often very effective in restoring
pain free movement of lifting the arm overhead. Proprioception is particularly
important for reinforcing correct movement patterns at this stage.
Posture of the thoracic spine, shoulder blade position and neck must be
addressed to rectify the problem permanently. Posture is not as simple as how
you sit or stand. If you constantly sit with your mid-back slumped, shoulders
rounded forward and head protruding, the muscles running along the length of
the spine become long and weak, making sitting up tall an effort, as the
muscles fatigue quickly. Muscles become tight in the chest, pulling the humerus
forward, and the muscles attaching the shoulder blade to the spine also
become long and weak. This combination makes it even more difficult to draw
the shoulder blades back into an effective stabilizing position. With the head
protruding forward the muscles running from the shoulders to the head are put
under tremendous stress. They often become tight and painful, contributing to
the ineffective movement pattern. These muscles are also responsible for
headaches felt on the side of the head and around the eyes.
As we age, if posture is not corrected the joints become stiff and resistant to
moving in the opposite direction, muscles shorten, ligaments and cartilage
around the joints stiffen, thus making the posture irreversible.
Finally, once the inflammation has resolved, the biomechanics corrected and
the posture improved, the focus lies on strengthen weak muscles. Exercises to
improve the endurance of the stabilizing muscles of the shoulder blade are
critical so the rotator cuff muscles have a stable base from which to work
from. The rotator cuff muscles must be strengthened in progressive stages.
For full recovery the exercises must include motions specific to the individuals
lifestyle, be it the swimming motion, painting, overhead lifting or computer
work.
Rehabilitation is a complex process the longer an injury is allowed to continue
without being treated, the more the body compensates, making recovery a
more protracted and involved experience. As for all injuries, the sooner you
seek treatment following an injury, the quicker the recovery and your return to
the activities you enjoy.