Pain and tenderness are common features in patients with back problems. Physical therapists (PTs) press and feel patients’ skin and soft tissues to find out where the pain is located. This exam method is called palpation. In this study PTs measured the amount of pressure it takes to cause pain in patients with chronic low back pain (CLBP).
The study was made up of two groups. One group had 30 women who had back pain for more than six months. The second (control) group were healthy volunteers (30 women) with no back pain. The goal was to see if the amount of pressure needed to cause pain is less in people with back pain compared to “normal” (healthy) adults.
The researchers measured pressure pain detection threshold (PPDT) in 10 places on the body. Some test sites weren’t near the back. Other test sites were near the spine.
They found all PPDT values (near and far from the spine) were lower for subjects with CLBP. The authors aren’t sure how to explain the difference. It could be based on how the nervous system works. Or there may be psychologic or emotional links.
The bottom line for PTs is that palpation may not be an accurate test of pain. People with CLBP are more sensitive to pressure than other healthy pain free adults.