Lifting, throwing, punching, pulling, pushing, swimming, and paddling with suboptimal shoulder mobility is a common problem in this modern world of desk slaves and non-movers. In a nutshell, we tend to predominantly move our shoulders with our arms in front of the body, having very little variety of shoulder movement. Most people walk around with hunched upper backs, heads that droop forward, chests that slump, high hips, rotated hips, and bodies which are carrying too much stress.
The reasons for each individual’s shoulder issue is unique, and the first concern would be to get an assessment by a qualified rehab professional. If you go for a generalized approach and dive straight into the shoulder (symptom), you might be missing the true cause of the issue, which could be anything from a stiff hip to a breathing limitation, which drives the head forward. It’s impressive how our bodies adapt to a dysfunction upstream or downstream.
The shoulder is inherently unstable. The human shoulder is made up of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone), as well as associated muscles, ligaments, and tendons. The glenoid  (shoulder socket) only contacts approximately 30 percent of humeral (upper arm bone) head. The labrum (cartilage ring) increases joint surface and stability is reinforced by ligaments and tendons. The compromise between mobility and stability results in a large number of shoulder problems not faced by other joints such as the hip, which is inherently more stable.
There is a negative pressure in a healthy shoulder joint, which acts like a vacuum and keeps the humeral head glued firmly to the glenoid fossa in a healthy way during movement. Significant shoulder injury can take away this negative pressure, making the joint less stable.
Common Problem Areas
Anything disrupting the lower body is mirrored in the upper body. For example, a right shoulder dysfunction mirrors a left hip dysfunction in most cases. When we walk we counter rotate, cervical and lumbar spine tend to move together, and the thoracic goes the opposite way.
Lack of mobility in one area of the body generally causes compensation in joints above or below the “stuck” joint. If you have poor thoracic spine (upper back) mobility and cannot extend your thoracic spine, you will need to compensate in your shoulders for sustained paddling. An injured shoulder follows a screwed up thoracic spine, just as an injured shoulder follows a screwed up cervical spine (neck).
The anterior (front) part of the shoulder capsule is the weakest portion of the capsule relative to the forces passing through the tissue. The anterior shoulder capsule becomes loose and weak with rounded shoulder postures (most people today), making the shoulder vulnerable to damage and degeneration. Chronic paddling and the unfortunate chance of impact injuries from wipeouts/collisions are two major culprits of shoulder capsule tears.
How Surfers Develop Shoulder Problems
The action of paddling in surfing strengthens the larger muscles around the shoulder, some of the major ones taxed being the pec major, pec minor, deltoids, upper trapezius, levator scapulae, lats, and serratus posterior. These muscles when strong relative to their opposite acting muscles tend to apply upward force on the arm bone, migrating it north toward the bone above. This is not a good thing because the arm bone can start hitting the bone above (acromion), leading to muscle impingement. The rotator cuff muscles when strong will apply a downward force on the ball of the arm bone, saving you from shoulder impingements.
Because of regular paddling, we tend to become strong in the muscles that apply this upward force and relatively weak in the rotator cuff muscles that apply downward force. This can result in the ball of the arm bone sliding upwards in the shoulder joint. Impingement Syndrome occurs when there is abnormal contact between the rotator cuff muscles and the roof of the shoulder (acromion). Normally, a sac of tissue (bursa) sits on top of the rotator cuff, allowing the muscles to glide smoothly as the shoulder moves in different directions. When the arm is raised, the space between the rotator cuff and acromion becomes smaller. There is usually enough room in the shoulder joint for this to occur without pain. With repeated paddling, irritation, and damage to the rotator cuff can occur and the bursa can swell. This decreases the space in the shoulder and compresses the rotator cuff muscles and causes pain.
A subtype of impingement is called internal impingement. This occurs as a result of imbalanced forces in the shoulder capsule, which is a fibrous tissue. In some people, the front part of the capsule is too loose or unstable, and the back part is way too tight. This results in an imbalance of forces across the joint, especially with overhead stuff like paddling. Abnormal contact between the rotator cuff muscles and the back part of the capsule occurs, damaging the rotator cuff, capsule, and labrum and ultimately causing pain. If this impingement is allowed to go on for an extended period of time it can cause small tears in the rotator cuff tendons, reduce blood supply, and important nutrition to the shoulder joint.
Rotator cuff injury is a continuum beginning with impingement and progressing to a cuff tear. The cuff tendons have areas of low blood supply, making healing more difficult after injury. As a result, the tendons degenerate with time. This is precisely why most tears occur in late, middle age.
Muscular imbalance is a key problem, but also so can be restricted mobility in the thoracic spine, neck, hips, and shoulders. Paddling places a massive amount of stress on the rotator cuff in general, they need to work their butts off to keep up with the stronger muscles that surround them. Paddling strokes result in overdevelopment of both the shoulder’s internal rotators (subscapularis), compared to external rotators (infraspinatus) and the anterior chest muscles (the pecs) relative to the posteri/or stabiliser muscles (rhomboids, levator scapuli, serratus anterior and middle/lower trapezius).
Another way surfing may lead to shoulder issues is through the hip flexor. Surfing creates tight hip flexors. The hip rotates toward the back foot and this over time creates imbalanced loading through the spine, hips, knees, ankles. Tension created by imbalances in the hip cause core instability, which affects your surfing and just about everything else.
Increased muscle-shortening keeps the right shoulder (natural footed) under stress and out of
alignment, decreasing its flexibility, coordination, and strength. Muscle imbalances from being right-handed causes the right hip to draw upward as the right shoulder is pulled down, creating ongoing stress that over time affects all of the joints in the body. The neck, chest, and the internal rotator muscles of the shoulders all shorten and limit normal range of motion.
Treatment involves restoring softness to overly tight muscles, flexibility in tight muscles/fascia, ensuring optimal mobility in the neck, upper back, and hips and strengthening the rotator cuff as well as weak opposing muscles.
Prehabilitation (injury prevention) or rehabilitation exercises, stretches, and physical therapy should be part of every surfer’s training in order to prevent the condition in the first place. Learning correct paddling technique and getting strong in foundational movements also helps to offset rotator cuff injuries. There is a difference in the pain we feel from muscle soreness and that from our joints. Respect the signals. It is important to rest and stretch the shoulder as needed to maintain shoulder health, especially if you want to keep surfing for life.
In conclusion, everything in your body is connected. For a lot of surfers, the front of our shoulders are over used, while the back of the shoulder is not. There’s also a lot of funky stuff going on in other parts of the body from the ankle up. If you’ve got funked up shoulders, your first priority will be to balance the shoulder joint first, gaining stability, offloading stress in overworked muscles, ironing out trigger points, stretching tight muscles, regaining healthy range-of-motion, and taking a break from movements that are causing you pain.