What is the bone that sticks out on top of shoulder?
Olivia Shea
Updated on February 28, 2026
The acromion is the bony tip of the outer edge of your shoulder blade (scapula) that comes off the top of the back side of this bone. It meets with the end of your collar bone (clavicle) at your shoulder. Shoulder impingement occurs when the tendon rubs against the acromion.
What causes bony lump on shoulder?
Bone spurs (also known as “osteophytes”) formation on the joints is often a result of arthritis due to aging and one of the most common areas a bone spur develops is under the acromion of the shoulder. Also, those whose jobs or sports require repetitive overhead movement are at risk for this condition.
Why is my acromion bone sticking out?
An injury to the AC joint is common, often caused by a blow to the shoulder or a fall onto an outstretched hand. The fall injures the ligaments that surround and stabilize the AC joint, forcing the clavicle to detach from the acromion. This creates a bump or bulge above the shoulder.
What does shoulder bone spur feel like?
Pain in the affected joint. Pain or stiffness when you try to bend or move the affected joint. Weakness, numbness, or tingling in your arms or legs if the bone spur presses on nerves in your spine. Muscle spasms, cramps, or weakness.
What is a Mass on shoulder?
A shoulder lump refers to a bump, growth, or mass in your shoulder area. You might feel it rub against clothing or the straps of a bag. Not all lumps are equal. Some might hurt, while others are painless or cause mild discomfort.
Is it normal to have a bone sticking out of your shoulder?
It can happen as a result of injury or nerve damage. The scapula, or shoulder blades, are flat bones that connect the upper arm to the collar bone. When they come out of place, it can cause scapular winging. Scapular winging is a rare condition that can be painful.
Why do I have a bone popping out of my shoulder?
Extreme rotation of your shoulder joint can pop the ball of your upper arm bone out of your shoulder socket. Partial dislocation — in which your upper arm bone is partially in and partially out of your shoulder socket — also may occur. A dislocated shoulder may be caused by: Sports injuries.
Why is my right collar bone bigger than my left?
“Clavicles are generally symmetrical, but asymmetry is not necessarily something to worry about,” says J. Mark Anderson, MD, DABFM, of Executive Medicine of Texas and who is board certified in family medicine. “Many people are born with one side more pronounced than the other,” continues Dr.