Having a noticeable dip or indentation in the ribs is a common anatomical variation that is usually harmless. However, in some cases, it can be a sign of an underlying medical condition. Here is an overview of the possible causes and treatment options for rib dips.
What is a rib dip?
A rib dip, also known as a dent in the ribs or chest wall deformity, refers to an inward curve or groove in one or more of the ribs. It creates a visible depression along the contour of the rib cage on one or both sides of the chest.
Rib dips are fairly common, estimated to affect 10-15% of the population to some degree. They can occur in men and women of any age but are most noticeable during the teenage years when the chest bones are still developing. The dip is usually located along the lower ribs on either side of the sternum (breastbone).
Normal anatomical variation
For most people, a slight indent in the ribs is simply due to normal variation in bone structure and muscle development. The ribs curve and bend in complex ways to form the thoracic cage that protects the heart and lungs. It is not uncommon for one or more ribs to grow at slightly different angles or proportions compared to the others.
Factors like genetics, bone density, posture, and muscle tone can all contribute to normal unevenness in rib contour without being a cause for concern. Uneven ribs are often more pronounced in thinner, athletic body types. If the dip has been present your whole life without any pain or breathing issues, it is likely just part of your anatomy.
Pectus excavatum
A pronounced, funnel-shaped depression across several ribs may be a sign of pectus excavatum – the most common congenital chest wall deformity. It is caused by an overgrowth of cartilage that pushes the sternum inward, resulting in a sunken chest appearance.
Pectus excavatum typically develops during puberty and is diagnosed through physical exam, CT scan, and measurement of the depression’s depth. Though often asymptomatic, some patients experience chest pain, palpitations, trouble exercising, and self-esteem issues from the appearance. Bracing or surgery may be recommended in severe cases to correct the deformity.
Signs and symptoms of pectus excavatum:
- Funnel-shaped hollow across multiple ribs
- Sternum sunken inward towards spine
- Depth of dip >2 cm
- Worsens during adolescent growth spurt
- May impact cardiac/respiratory function if severe
Physical trauma
An injury that directly impacts the ribs can also cause indentations or alignment issues. Fractures from falls, motor vehicle accidents, or sports collisions often require the chest to be stabilized to heal properly. If ribs do not set back into perfect position, depressions may result along the break lines.
Blunt trauma from a forceful blow can displace cartilage at the rib joints. Dislocations and subluxations cause the ribs to move out of alignment, which alters their symmetry and contour. Seek medical treatment for trauma-related rib indentations to assess for damage. Physical therapy may help realign ribs and regain strength.
Causes of rib trauma:
- Falls and accidents
- Contact sports
- Motor vehicle collisions
- Fights or physical abuse
- CPR compressions
Muscle irregularities
The shape and thickness of chest wall muscles also influence the appearance of ribs underneath. If certain muscles are overdeveloped compared to others, they can create visible dips and bulges in the rib cage structure.
For example, tightness or spasms in the intercostal muscles between ribs can pull indentations inward. Weakness of the serratus anterior muscles allows the shoulder blades to protrude posteriorly, which makes the ribs collapse forward. Strengthening exercises and postural retraining may help balance the muscles for symmetrical ribs.
Muscle imbalances affecting rib contour:
- Tight/spasming intercostals
- Weak serratus anterior
- Overdeveloped pectoralis major
- Rounded shoulders/poor posture
Scoliosis
Scoliosis is an abnormal sideways spinal curvature that also distorts the position of the rib cage. The ribs on the convex side of the scoliotic curve protrude out, while the ribs on the concave side appear sunken inward. Mild to moderate cases produce minor rib asymmetry, but severe scoliosis can significantly displace ribs from their normal alignment.
While scoliosis can affect people of any age, it most often develops in childhood and adolescence during growth spurts. Signs to watch for include uneven shoulders, one hip higher than the other, leaning posture, and clothes not hanging properly. Braces, physical therapy, and surgery are treatment options depending on the severity.
Rib changes seen with scoliosis:
- Rib hump/protrusion on convex side
- Rib depression on concave side
- Rotation of rib cage
- Changes posture/gait
- Affects spine curvature
Flared ribs
Some people have a flared or splayed appearance in their lower ribs instead of a defined dip. This wider, more horizontal angle of the lower false ribs is another common skeletal variance. Women tend to have greater rib flaring due to broader pelvic bones.
If the flaring is symmetrical, it is usually just a normal feature of bone structure. However, uneven flaring on one side can indicate scoliosis or trauma. The ribs angle outward on the side of the thoracic curve in scoliosis. Broken ribs often heal with greater lateral displacement.
When to see a doctor
Schedule an appointment with your doctor if:
- The rib indentation is deep, uneven, or getting worse
- It is accompanied by chest pain or breathing problems
- You have a family history of chest wall conditions like pectus excavatum
- You experienced trauma like a car accident that could have injured ribs
- There are posture changes like uneven shoulders or leaning to one side
Diagnostic tests may include:
- Physical exam
- CT scan
- Pulmonary function tests
- Echocardiogram
- Musculoskeletal ultrasound
- Scoliosis x-rays
Based on the exam and test results, your doctor can determine if the rib dip is normal or requires treatment.
Treating rib dips
For mild indentations without symptoms, no specific treatment is necessary other than reassurance about the anatomy. For dips related to underlying conditions, possible interventions include:
- Physical therapy – Stretches and strength training to balance chest wall muscles and posture.
- Pain medication – Over-the-counter anti-inflammatories to relieve trauma-related rib discomfort.
- Bracing – Custom braces to reshape abnormal pectus excavatum or scoliosis ribs.
- Surgery – Ravitch procedure or Nuss procedure to repair depressed sternum in severe pectus excavatum cases.
- Posture correcting exercises – Stretching and exercises to improve posture affected by scoliosis.
Cosmetic correction is also an option for some patients who feel self-conscious about the appearance of their rib indentations.
Living with a rib dip
For most people, slight rib indentations require no intervention and are unlikely to cause problems. But it is still important to have your symptoms evaluated by a doctor to check for underlying causes.
Here are some tips for living with non-symptomatic rib dips:
- Maintain good posture through regular exercise.
- Stretch chest muscles like the pectorals to avoid tightness.
- Build strength in the upper back to counteract slouching.
- Use posture braces or supports if needed.
- Limit contact sports that could traumatize the chest.
- Focus on overall skeletal health through diet and weight-bearing activity.
- Be open with romantic partners to avoid self-consciousness.
- See your doctor yearly to monitor for any changes.
While rib indentations can be distressing if they appear suddenly or seem pronounced, they are typically harmless manifestations of the amazing complexity of our bone and muscle anatomy. Learning about the possible causes and seeing your doctor for evaluation is the first step to getting answers and setting your mind at ease.
Main causes of rib dips:
| Normal anatomical variation | Genetics, bone density, posture, muscle tone |
| Pectus excavatum | Congenital overgrowth of chest cartilage |
| Physical trauma | Fractures, dislocations from injury |
| Muscle irregularities | Tight/weak muscles distorting ribs |
| Scoliosis | Sideways spinal curvature |
Conclusion
Discovering a new dent along your rib cage can be alarming, but try not to panic. In the majority of cases, a slightly indented rib is simply part of your normal anatomy and requires no treatment other than reassurance from your doctor. But more pronounced or painful dips should be medically evaluated to assess for rare underlying conditions like pectus excavatum or scoliosis. With proper diagnosis and management, even abnormal rib contours can be improved to restore comfort and self-confidence.