Hello , doctor, my uncle was hurt himself in a gym .there is nothing wrong with his muscles, just sore in the middle of lumbar.is that hurt his ligament?

Midline lumbar pain : Pain in mid-line of spine generally connotes presence of a more serious underlying disease process as compared to pain on the sides of the spine. Serious spinal back injuries can present with mild symptom. Additionally, pain is a subjective & should not always be used as the sole predictor of what disease process may be involved. A ligamentous injury is possible. Exam, x-ray, +/- ct is needed.

Low back pain: If the pain continues, he should see his pcp. However, light exercise is advised. Proper stretching before and after exercise is necessary. As well as proper technique with exercise. Look up the mckenzie method on youtube for low back stretches. Over the counter nsaids are ok for a short time of he doesn't have kidney disease or gastric ulcers.