Effects of low-level laser therapy on hamstring strain injury rehabilitation: A randomized controlled trial.

Researchers in this 2020 trial wanted to know whether low-level laser therapy, applied right after exercise-based rehab sessions, could speed up recovery from hamstring muscle strains in young male athletes. Twenty-two amateur athletes with hamstring injuries were split into two groups: one received the laser treatment and the other received a placebo (fake treatment), while both groups followed the same structured exercise program. The findings were straightforward and somewhat surprising.

The laser group returned to sport in about 23 days on average, while the placebo group returned in about 24 days. Both groups regained flexibility and strength at similar rates throughout their rehab. There were no re-injuries in either group within six months after return to sport.

The bottom line is that the laser therapy, as it was used in this study, did not appear to make a meaningful difference to how quickly athletes recovered or how well they performed.

If you've strained your hamstring and you're curious about laser therapy, here's what this study found. Researchers looked at whether shining a special low-level laser on the injured muscle after each physiotherapy session could help you get back to sport faster.

Half the athletes got real laser treatment and half got a fake version, but everyone did the same exercises. Both groups got better at about the same speed, taking roughly three to four weeks to feel ready to return to activity.

Neither group had injuries come back within six months. While laser therapy sounds like it could help, this evidence suggests it doesn't add anything extra on top of a good exercise program.

That doesn't mean it's harmful, just that the science from this trial didn't show it made a real difference in recovery.

This is a summary of research, not medical advice. Talk to your own healthcare provider about anything affecting your care.

This randomized controlled trial offers a fairly clean negative finding on LLLT as an adjunct to exercise-based hamstring rehabilitation. The study was reasonably well-designed, with matched groups at baseline and a protocol of LLLT applied immediately post-exercise across the entire rehab window.

Both strength and flexibility gains tracked similarly between groups, and time-to-return to sport showed no separation (LLLT 23±9 days versus placebo 24±13 days). The lack of re-injury in both groups over six months is reassuring but doesn't differentiate the intervention.

The sample size was modest at 11 per group, which limits power to detect small effects if they exist. This adds to a growing body of evidence questioning whether LLLT adds clinical value when an evidence-based exercise program is already in place.

The findings don't rule out context-specific benefits in other injury types or severity profiles, but for routine hamstring strain management in this population, current evidence indicates the laser component is not necessary.