​A “Hook Manoeuvre” test being done on a patient to assess if he has slipping rib syndrome, a form of chest-wall disease. It is the only test that can provide an accurate diagnosis of the condition. (Image: National Heart Centre Singapore)

  • The National Heart Centre Singapore has seen an increase in chest-wall diseases

  • This is a group of chest-related conditions affecting the ribcage and overlying muscles

  • One reason for the increase may be a lack of muscle conditioning and periods of inactivity during the Covid-19 pandemic, a surgeon said.

  • Chest pain is a common symptom of chest-wall diseases, so they may be mistaken for heart diseases

  • A 28-year-old man with slipping rib syndrome, an under-diagnosed chest-wall disease, told of how it was like to live in pain for a year

SINGAPORE — Once fit enough to complete 150 sit-ups every day, Mr Niko Yeo was forced to stop exercising after he started experiencing pain around his chest area. This happened towards the end of 2020 during the Covid-19 pandemic. 

Despite seeing several doctors, chiropractors and undergoing multiple scans and X-rays over a year, he was not able to get a proper diagnosis or treatment. One doctor thought it was due to irritable bowel syndrome; others said it was muscle pain.

Describing the sensation, the 28-year-old IT consultant said: “It felt like there was a rock under my ribcage.

“Most of (the doctors) attributed it to muscle pain and my body became weaker as I had to stop exercising. It was disheartening not to be able to find a cause for the pain.”

It was only after Mr Yeo consulted a relative — a doctor who noticed a clicking sound when he bent down — that he made some headway.

Both of them did some research online and suspected that he had an under-diagnosed and rare chest-wall disease called slipping rib syndrome.

It occurs when cartilage that holds the lower ribs to the rest of the ribcage becomes loose, or slips, leading to pain in the lower chest or upper abdomen.

The unusual condition was eventually confirmed in 2021 — about a year after he first developed symptoms — using a specialised bedside assessment by thoracic surgeon Soo Ing Xiang.

Assistant Professor Soo is a consultant with the department of cardiothoracic surgery at the National Heart Centre Singapore (NHCS).

By then, painkillers could not ease Mr Yeo’s pain.

“I felt relieved when I got the diagnosis. At that point, I thought (the pain) was all in my head,” he said.

Mr Yeo’s pain is not imagined. In the past two years, NHCS has seen an uptick in an under-diagnosed group of thoracic (chest-related) conditions affecting the ribcage and overlying muscles called chest-wall diseases.


Slipping rib syndrome is one of them. Another chest-wall condition is costochondritis, which is caused by inflammation of the joints between the bony ribs and softer cartilages.

Last year, Asst Prof Soo who diagnosed Mr Yeo’s condition saw an average of three to five patients for chest-wall diseases at every clinic session.

He estimated that he has seen a 30 to 50 per cent increase in such cases since start of the Covid-19 pandemic.

“There are cases seen in the past but there has been an increase during the pandemic. Due to lack of (muscle) conditioning and periods of inactivity, muscle strains involving the chest wall can be more common,” he told TODAY.

“We hope to increase public awareness of these diseases so that more patients can get the appropriate treatment and recover functionally.”


When someone complains of chest pain or discomfort, the first thought is often whether the person is having a heart attack or other cardiac-related condition.

However, chest pain is also one of the most common symptoms related to chest-wall diseases.

In severe cases, patients may get shortness of breath or chest swelling, with some experiencing intense pain that affect their everyday life.

"For patients with slipping rib syndrome or any other chest-wall diseases, it is essential to accurately diagnose the condition and locate the problem in the chest wall. This requires experience as well as an in-depth knowledge of the chest anatomy," Assistant Professor Soo Ing Xiang, consultant with the department of cardiothoracic surgery at the National Heart Centre Singapore.

Since chest pain is commonly presented in chest-wall diseases, Asst Prof Soo said that it may be misdiagnosed as heart disease. Sometimes, the pain may be localised (in one spot) and occurs with specific movements, akin to a muscle strain, he added.

Ms Rachel Stephens, a physiotherapist with NHCS’ Cardiac Physiotherapy Services, said for example that pain in slipping rib syndrome may be worsened with movements such as stretching, twisting the trunk, bending and carrying heavy loads.

Pain may also worsen when doing sports such as swimming, running and horseback riding, which involve the abdomen and heavy breathing, she added.

In severe cases, there can be shortness of breath and chest swelling, with some experiencing intense pain that affect their everyday life and how they function.


There are multiple factors why chest-wall diseases occur.

In the case of costochondritis, for example, Asst Prof Soo said that the main risk factor is the wear and tear of the chest-wall joints — similar to that of arthritis in older adults.

A traumatic injury to the chest wall, say, from a fall, is another reason why some people have chest-wall conditions.


Asst Prof Soo said that slipping rib syndrome tends to be seen in the younger age group.

He explained that many patients are likely to have inherent weakness of the chest-wall joints since birth, and symptoms may manifest due to lifestyle habits or repetitive exercises that stress the joints.

When asked if Mr Yeo’s condition was aggravated by doing too many sit-ups, the surgeon said: “The repetitive exercise could worsen the condition, but usually there is already underlying chest-wall weakness that is the main reason.

“In the case of costochondritis, carrying heavy weights on the same side can also stress the chest-wall joints.”

One costochondritis patient whom the surgeon saw had the habit of slinging heavy items over a shoulder, which puts stress on the chest-wall joints over time.

weight lifting
Image source: Victor Freitas/Pexels

He also said that many people who engage in weight training without proper conditioning may also end up straining the joints and muscles in the chest wall.

“Besides using their upper limb muscles, many people do not realise that they may also strain the chest-wall muscles and joints when lifting something heavy above the chest.”


Asst Prof Soo said that chest-wall conditions are usually diagnosed via a detailed bedside examination even if scans may appear “normal”.

“For patients with slipping rib syndrome or any other chest-wall diseases, it is essential to accurately diagnose the condition and locate the problem in the chest wall. This requires experience as well as an in-depth knowledge of the chest anatomy.”

In Mr Yeo’s case, a detailed consultation was carried out, during which a diagnostic test called the “Hook Manoeuvre” was performed to assess if he had slipping rib syndrome.

The Hook Manoeuvre, which is performed while the patient is lying on his or her back, involves placing the fingers of the examiner along the edge of the last rib and lifting upwards and towards the patient’s head.

Ms Stephens the physiotherapist with NHCS explained that if the movement causes the patient to experience a sharp pain or produces a “pop” sound as the rib moves, then the patient is confirmed to have slipping rib syndrome,


For patients with severe symptoms, such as Mr Yeo, surgery is one of the treatment options.

For mild cases, lifestyle changes such as changing the way one carries heavy items and proper conditioning through physiotherapy to strengthen the thoracic muscles, can help.

Asst Prof Soo said: “Sometimes, instead of going for surgery or taking painkillers, modification of lifestyle can help improve symptoms. For example, in most of my patients with costochondritis, their symptoms got better with a change of lifestyle habits.”

NHCS patient with physiotherapist and doctor slipping rib syndrome exercise demo
Physiotherapist Rachel Stephens (centre) giving Mr Niko Yeo (left) a demonstration of some exercises he needs to do to treat slipping rib syndrome, as Assistant Professor Soo Ing Xiang (right) looks on. Image: National Heart Centre Singapore

With the appropriate treatment, patients can fully recover from chest-wall disease, he added.

“Once we ascertain that it is chest-wall pain, that is not coming from the heart or other reasons, we can then treat it appropriately.”

The three main types of exercises used in physiotherapy are stretches, strengthening and stabilisation exercises.

Ms Stephens said that some chest-wall diseases can result in tightness at the chest muscles.

“Stretches can lengthen these tight or shortened muscles and, in turn, help to reduce tightness and pain,” she added.

Strengthening exercises can help boost weakened muscles, while stabilisation exercises will help hold the joints in a better position to enable the chest wall to be more stable and effective in movement.

Mr Yeo underwent surgery to treat his condition last December.

The day surgery procedure involved reattaching and remolding the “slipped rib” back to the rest of the ribcage. He was able to return to work two weeks after the surgery and has made a full recovery.

He said: “Immediately after the surgery, the ‘rock’ I had felt under my ribcage was gone.”

He has returned to exercising. However, he is so traumatised by his year-long pain that he no longer does sit-ups, despite being given the green light by the doctor.

“I don’t think I’ll take the risk and go through this again.”