Hi Sarahkelly, thank you very much for your replay, but i don't believe that was Latissimus Dorsi....
The spot was about 4-5 cm away from his spinal at the upper edge of his right QL
I hop you understand .....
sorry for my bad English , thanks again

For the record , I treat him 3 times , and hopefully he is fine for the time ..
I learned him several stretches for
Latissimus Dorsi, QL, Hamstrings, lumbar spine, Iliopsoas etc....and he is trying to practice them every day.
In the next 2-3 days I will learn him how to make those muscle stronger to avoide a future problem