Author: Dr. David Thorpe, President of WorkRite Safety
Pulling tarps, cranking gears, lifting freight, shifting, opening and closing doors all day can put a lot of stress on your shoulder joint.
It can be easily injured and is a common area for injury. Truckers are highly susceptible to shoulder injuries, due to the constant vibration while driving and the nature of their job.
The shoulder joint consists of two bones: the humerus (upper arm bone) and the scapula (shoulder blade bone). The shoulder is the most mobile joint in the entire body. It can go up, down, back, forth, side to side and round and round easily.
This allows you to move your shoulder in any direction. Unfortunately, this increase in mobility comes with a price and that is stability. It is not a very stable joint and can become dislocated easily. Although dislocations can occur, they are rare.
For your shoulder to “pop out,” there needs to be a significant trauma or force applied to the joint. The rotator cuff muscles (supraspinatus, infraspinatus, teres minor and subscapularis) ligaments and the joint capsule of the shoulder are responsible for its stability.
Rotator cuff injuries are one of the most common types of injury associated with the shoulder. These muscles are susceptible to many injuries, which can cause weakness, tenderness and pain.
Overloading of these muscles as a result of poor biomechanics and repetitive motions can lead to impingement syndromes, tendonitis and/or tears. Constant irritation over a prolonged period of time can also lead to dysfunction of the muscles as well as the shoulder joint.
Tendonitis of the shoulder (rotator cuff muscles) primarily occurs due to repetitive movements causing irritation of the muscles that stabilize the joint.
Tendonitis can also be caused by straining, twisting and turning improperly which will microscopically damage the tendon. If a muscle is chronically being irritated, it does not have the opportunity to heal properly.
Over time this may weaken the tendons, making them more prone to tears. If you experience any type of sharp pain when you try to move your arm, tendonitis may be present. The severity of pain will be determined by the amount of inflammation that is present.
When a muscle articulates with a bone, the body has a fluid filled sac to eliminate any excessive amounts of friction between the two. This fluid filled sac is known as a bursa, and is found throughout the body (knee, hip and shoulder).
A bursa sits between a muscle and bone and acts like a buffer between the two. Sometimes this bursa can become inflamed and you get a bursitis.
With inflammation comes swelling, resulting in the bursa getting larger.
In the case of the shoulder, when the bursa enlarges, it gets trapped under the acromion (part of the shoulder blade) along with the supraspinatus muscle.
This is known as an impingement syndrome, because the bursa and suprapinatus are getting “impinged” by the acromion. Sharp pain will be experienced when you try and put your arm behind your back, or on your belt buckle. Once the muscle or bursa is “pinched” you will feel pain.
The shoulder joint is encapsulated by a membrane – think of a ball that is inside a balloon. It envelopes the entire joint and includes the ligaments that attach the shoulder bones to each other.
When this capsule becomes inflamed due to injury, it can also cause pain. Chronic inflammation (for weeks to months) can lead to a shoulder condition known as adhesive capsulitis (frozen shoulder). Due to the pain and stiffness, sufferers avoid moving their shoulder. Unfortunately, lack of movement of the shoulder directly compounds the problem and the shoulder gets even stiffer.
Since this condition is very painful, many individuals develop a psychological barrier to moving the joint, when there are no physical findings to warrant pain with movement. It is very important that movement is encouraged to ensure a quick recovery.
The type of shoulder problems that have been discussed, are primarily due to repetitive motions and improper working technique (biomechanics).
These injuries are not serious but need to be taken care of ASAP in order to prevent them from becoming a chronic (long-term) condition. To prevent yourself from having shoulder problems, make sure that your rotator cuff muscles are strong and flexible.
Also, make sure any overhead activities are being done properly without putting too much strain on the shoulder.
Visit your health practitioner, personal trainer and/or massage therapist to find out ways to improve the health of your shoulders.
Until next month take care and drive safely!