I purchased this machine to treat my patellar tendonitis (jumpers knee) at home. Although I was worried about the strength of this unit, I can report that it is plenty strong enough for normal uses. If you've ever had ultrasound therapy, you will understand what I mean when I say that ultrasound can give you the feeling that you your internal tissue is "heating up." When this happens, it can become quite uncomfortable if the machine is left in the same place for too long or on too high of a setting. The fact that this unit produces the exact same effects tells me quite convincingly that it is actually delivering a strong blast of ultrasound deep into my petallar tendon. I would recommend to anyone thinking about buying it for moderate home treatment.