I bought one of the original Chi Infratonic machines over 7 years ago, and it worked great (still), but it had fewer frequencies, and was not portable, making it more difficult to use.

This newer model [Latest Version is CHI Palm] is rechargeable, very portable, and has an additional frequency for acutely painful areas. I just had Achilles tendon surgery in April, and using this has speeded my recovery from a slightly numb area in my heel after the surgery.

I keep it under my pillow, to use on my back with the deep calm setting for those areas that get so tight and painful that I get numbness in my fingertips. I leave it on all night when I use it, and even so, the charge lasts for weeks. I have even taken it to work and used it on my hip when I have had difficulty with pain in my legs.

The combination of stretching, icing, massaging and this Infratonic machine has really helped my 60-year-old body with muscle soreness and pain! 5 out of 5 stars.

Rosekat