Overview
The chest is packed with muscles, ribs and joints that all get blamed for chest pain — and the language around them can be confusing. This glossary explains the terms you'll see across InjuryAtlas's chest and pec pages in plain English.
Terms are listed alphabetically, with links for the full picture.
A
Axilla: The medical name for the armpit, where the pectoralis major attaches and where lymph nodes sit.
B
Bench press: A pressing exercise that loads the chest, shoulders and triceps — a common source of pec and shoulder strain when progressed too fast.
Breathing mechanics: How the diaphragm, ribs and intercostal muscles work together to draw air in and out. See diaphragm anatomy.
C
Chest wall: The structure of ribs, muscles, joints and connective tissue that forms the front and sides of the upper body. See chest wall anatomy.
Clavicle: The collarbone, which connects the sternum to the shoulder and anchors the pec major.
Costochondral junction: Where a rib's bone meets its cartilage at the front of the chest — the usual site of costochondritis.
Costochondritis: Inflammation of the cartilage where ribs attach to the breastbone, causing sharp chest pain with pressing, breathing deeply or lying down. See costochondritis.
D
Diaphragm: The dome-shaped muscle beneath the lungs that drives breathing. See diaphragm anatomy.
Doorway stretch: A common pec stretch — placing the forearm on a door frame and stepping forward to open the chest.
F
Floating ribs: The lowest two pairs of ribs, which attach to the spine but not to the front of the ribcage.
I
Intercostal muscles: The muscles between the ribs that assist breathing and stabilise the chest wall. See intercostal muscles anatomy.
Intercostal strain: A tear or overload of the muscles between the ribs, causing pain with breathing, twisting or lifting. See intercostal strain.
M
Muscle belly: The fleshy middle part of a muscle between its two tendon attachments.
Muscle strain: An injury from overload — muscle fibres stretch or tear. Strains are graded by severity.
P
Pectoralis major: The large fan-shaped chest muscle that brings the arm across the body, rotates it inward and assists pressing. See chest wall anatomy.
Pectoralis minor: The smaller chest muscle beneath the pec major that stabilises and tips the shoulder blade forward.
Pec insertion: Where the pectoralis major tendon attaches to the humerus (upper arm bone). A complete tear here is a serious injury. See pec major strain and tear.
Pressing: Any pushing movement — push-ups, bench press, overhead press — that loads the chest, shoulders and triceps.
R
Rib fracture: A break in one of the ribs, usually from direct impact, causing sharp pain with breathing and twisting. See rib fracture.
Ribcage: The bony cage of 12 pairs of ribs and the sternum that protects the heart and lungs. See ribcage anatomy.
S
Serratus anterior: The muscle on the side of the ribcage that holds the shoulder blade against the wall of the chest — key for pushing and overhead strength.
Sternoclavicular joint: The joint where the collarbone meets the breastbone, sprained by falls or direct blows. See sternoclavicular joint sprain.
Sternum: The breastbone, the flat bone at the front of the chest where the ribs attach.
T
Tendon: The tough cord of connective tissue that attaches muscle to bone.
Tendon avulsion: When a tendon tears completely away from the bone, sometimes pulling a fragment of bone with it.
Tietze syndrome: A less common cousin of costochondritis involving visible swelling of one or more rib-cartilage joints.
Related Resources
- Chest wall pain
- Chest pain red flags
- Return to pressing after pec injury
- Chest injury prevention for pressing
This information is for education only and is not a medical diagnosis. Sudden crushing chest pain, pain with shortness of breath, dizziness or pain spreading to the arm or jaw needs urgent medical assessment.