Infrared Thermal Therapy

Meng-Si Peng et al. (2022) · JAMA network open

This assessor-blinded randomized clinical trial with 113 adults explored whether exercising in water (therapeutic aquatic exercise) works better over the long term than common physical therapy modalities for chronic low back pain, meaning pain lasting at least 3 months. The modalities were transcutaneous electrical nerve stimulation (mild electrical pulses applied through the skin) and infrared ray thermal therapy (heat delivered by infrared light). Aquatic exercise meant guided, active exercise in a pool, where buoyancy and water resistance change how the body carries load. The authors note that low back pain is common and costly, and that no earlier trial had compared these two approaches or followed participants for a full year. Participants were 18 to 65 years old (average 31 years; 59 women, 54 men) and were randomly placed into an aquatic exercise group (56 people) or a modalities group (57 people). Both groups attended 60-minute sessions twice a week for 12 weeks. The aquatic group did a 10-minute warm-up, 40 minutes of water exercise at moderate effort (about 13 on the Borg scale) and a 10-minute cool-down; the modalities group received 30 minutes of nerve stimulation and 30 minutes of infrared heat. Measurements at baseline, 3, 6 and 12 months used the Roland-Morris Disability Questionnaire (24 yes/no items on daily activities limited by back pain) and a 0-to-10 pain rating scale. The aquatic group had lower disability scores than the modalities group at every check: 1.77 points lower at 3 months (P = .006), 2.42 lower at 6 months (P = .006) and 3.61 lower at 12 months (P = .001), so the gap widened over time. At 12 months, 46.43% of the aquatic group improved by at least 5 disability points (a change the authors treat as clinically meaningful) versus 7.02% of the modalities group. Most-severe pain was 0.79, 1.34 and 2.04 points lower in the aquatic group at 3, 6 and 12 months. Sleep quality, fear of movement and overall quality of life (SF-36) also improved more with aquatic exercise (P = .02, P < .001 and P = .003 for the overall group-by-time effect). Not every measure separated the groups: overall SF-36 scores were nearly identical at 3 months (P = .92), and work-related fear-avoidance scores did not differ. Treatment-related pain was uncommon in both groups (3.6% versus 7.0%). The authors suggest that water-based exercise may offer longer-lasting benefit than passive modalities for chronic low back pain, in part because it is active exercise. They state clear limits: participants were mostly young with fairly low pain, no one could be blinded, the comparison group did not exercise so the water itself cannot be credited alone, and costs were not examined. The authors call for trials that add a land-exercise group, combine both approaches, and include older people with more severe pain.