To educate the patient regarding shoulder functional mechanics and how it directly relates to the short and long term goals of physical therapy care, I have adopted the analogy of shoulder and car; something everyone seems to understand. Having an appreciation in this regard enhances the rehabilitative process and lessens the likelihood overuse and subsequent pain.
Rib Cage = Car Frame
A sturdy car frame is a make or break deal. Bent or twisted and the car does not move smoothly down the road or is allowed to disperse energy from the engine at its full capacity. The same rings true for the rib cage. It serves as a framework of which the shoulder blade is secured and if one becomes round shouldered due to poor posturing, osteoporosis or scoliosis, the efficiencies of the mechanical function and strength output of shoulder blade and ultimately the ball and socket joint are impaired.
Shoulder Blade = Engine block
The engine block and shoulder blade are the originators of the dynamic power for the shoulder. As one would expect, if the mechanical function is impaired, so is the output and the risk of mechanical wear and tear at other structures of the system.
Scapular Muscles = Engine Block Hardware
The shoulder blade musculature serves as the thru bolts to secure the blade to the rib cage. These include the: serratus, upper and lower trapezius, rhomboids.
The Socket = The Hub
The ball of the humerus sits in the socket like a wheel on the hub. Obviously, the mechanical function needs to be perfect or the parts start to wear out. Just like the hub rotating the wheel and tire, there needs to be rotation and not shear across the surface of the socket.
The Ball = The Wheel/Tire
As noted above the ball needs to move in a congruent fashion on the socket. If the lug nuts are loose (see rotator cuff below) or one is driving down the road with the brakes on (adhesive capsulitis/frozen shoulder) structures are going to fall into disrepair.
Rotator Cuff = The lug nuts
The four rotator cuff muscles in conjunction with ligamentous structure, keep the ball in the socket. Even the most powerful engine is ineffective if the lug nuts are loose.
Major Muscles = The Drive Shaft
Everything in front of and behind the drive shaft needs to be fully secured and mechanically sound if the force of the drive shaft is to be efficient. Major muscles such as the deltoid, latissimus, trapezius and pectorals need a stable scapula (shoulder blade) and ball and socket joint to allow us to push, pull, swing and lift.
Shoulder Injection = Turning up the radio when you have a bad muffler
I make all of my patients well aware of this fact. Unless the injury is very minor, an injection will not solve a shoulder issue, you have to fix the muffler and this is the goal of physical therapy care. The injection serves as a pain killer and concentrated anti-inflammatory to allow for improvements in mechanical function to occur via a guided home exercise program. The anti-inflammatory component will work for multiple weeks and one need be careful to not fall into the temptation of being too aggressive with the shoulder girdle with daily activities and exercise under the guise of a pain free status. Equally important, the no pain, no gain concept does not apply for someone recently injected with respect to their home exercise.
By the time you get to my office, you are no longer a brand new Porsche but more like a 65’ Caddy. It just takes a little more TLC to keep things running. But if done consistently and properly, you’ll get down the road just fine.