Linda was on her way to work as usual one day last week. She got into the car as she always does with her purse and a few items she needed for the day arranged on the front seat. She started down the driveway toward the street hurriedly, no doubt in attempt to make up for time lost on a last-minute crisis with a child. Near the end of the drive way was a large preoccupied deer, literally in the headlights, grazing in the yard. Both the deer and Linda were startled, as neither expected the other.
Linda slammed onto her brakes. Since the paved driveway was dry, traction was excellent. This alarmed the deer, who gracefully melted into the receding darkness of the early morning. Linda's car stopped moving, but neither Linda nor the items on the front seat did. Fortunately, she did not have hot coffee in her hand.
She was wearing her shoulder harness, so she did not hit the steering wheel. Her seatbelt stopped the progress of her hips suddenly so that her lower back was flexed forward at the speed the car was traveling prior to the hard brake. At the instant she saw the deer, she had just enough time to brace herself for possible impact with a death grip on the steering wheel as she also locked her left elbow. Unfortunately, this occurred at the same instant she was being thrown forward at about 15 miles per hour against the steering wheel, which was stopped along with the rest of the car.
The next day, Linda could not raise her left arm past the level of her shoulder without significant pain in the shoulder. The pain area expanded to the shoulder blade over the day, and it was radiating down the front and side of her left arm down by the next evening. This made it difficult to accomplish activities of daily living. It would come to a head, so to speak, when she could not arrange her hair.
Two days later, Linda had all she wanted of this inconvenience and reported to the clinic for help. Her chief complaint was the radiating pain down the arm and inability to use her shoulder.
One is tempted to blame this pain syndrome on the neck. Sudden stops can certainly cause issues in the neck with injury to nerve roots that can radiate down the arm. Where her arm pain manifested itself suggests a specific nerve that runs down that area. However, provocative orthopedic tests we perform on the neck to localize problems were negative. Other orthopedic tests that assess the shoulder, however, were strongly positive. When placed in context with the specific details of the history and the physics of this injury, attention is rightly turned to the shoulder joint.
The shoulder is a ball and socket joint like the hip, but there are important differences. The hip has a deep socket, so range of motion is limited, but strength is gained so it can support many times more than your body weight. The shoulder has less of a socket, more of a groove, so range of motion is large (for throwing footballs). The consequence of a shallow socket, however, is relative instability.
The shoulder joint is a complex confluence of the shoulder blade (scapula), the arm bone (the humerus), and the collarbone (clavicle), which acts as a stabilizing strut for the joint. With the physics of this injury, it is common for the ball of the humerus (the arm bone) to be driven slightly out of its groove. This is a partial dislocation of the joint that affects how the entire joint functions, forcing it to work inefficiently.
As the day wore on, the inefficiency of the shoulder joint caused Linda to recruit additional muscle power to operate. These muscles eventually tire, and the pain is extended as they fatigue.
Fortunately, the issue was simple to address. An adjustment of the shoulder blade (the scapula), the arm bone (the humerus), and the collarbone (clavicle) restored the full range of motion for the shoulder. Deep ultrasound for the fatigued muscles alleviated the soreness. She was immediately able to approximate the motions of hairdressing without pain and only minimal soreness. She went on her way with the full ability to primp and look her best.
I have not heard from the deer, and neither has Linda. This suggests that the deer was likely uninsured, explaining his fleeing the scene. Linda will likely look at the end of the driveway on the way out from now on, though, knowing that at least once, the buck stopped there.