I be so sorry to hear that some people be hurt themselves with this item . I have have no problem at all with it and I be very happy with it . I be so bad about do thing consistently and almost do not get this just because I figure it would end up sit around gather dust remind I of what I should be do to get in better shape before it be all down to my ankle . but I have no problem find the time to work out with this . who do not have 6 minute ? it be definitely a work out and I can feel it afterward but not in a bad way . I do not do the behind the head thing for the first several day - perhaps a week or more of use it daily - until I feel more confident with the item itself and comfortable with how it work and shift and all that . then I do not push it because you can feel that you be work on area that usually do not get much attention . if you do it right and as someone else mention `` listen to you body '' you can actually work out stress kink in you neck . I stretch with it in my hand first and I do long slower movement with it at first too to sort of loosen up . just like before any exercise - you should get you muscle warm up first . you should never just jump right in and do vigorous exercise or any exercise you have never do before without test the water first anyway . only you know you body and what it be strength and weakness be . I tend to have problem in my right arm and hand so I try and build up the strength in that arm by do shorter work out with it but more often . since I be horribly right handed - my right hand take all the abuse and all the activity so my left arm be worthless too but in a different way - I work that one out for longer stretch though not as many time during a workout as the right . I end up do they both about the same I just spread out the right one more so I do not aggravate exist problem there and hopefully strengthen it so that the muscle will be stronger and less susceptible to minor tweak and twinge . my arm be get icky flabby even though I be relatively active just because I be not a spring chicken anymore -lrb- though I 'll deny it if you say it out loud to my face -rrb- and they be look - oh i do not know - weird ... lol - but they look so much better now . I swear by this product . just do not go crazy with it right away and do not try and do what the fitness freak do unless you be already one . do what you know you can do and then just push the envelope at you pace a little more everyday . I increase my rep by at least 5 or 10 every work out . now I extend the length of the whole work out itself . I have even start use it to work different area that make my back feel great . oh and this be probably obvious yet it never hurt to mention this - you should really make sure you always drink plenty of water and especially after a work out . that help you muscle too - a lot !!! it really can not be overstate . -lrb- no - I do not work for any organization affiliate or associate with this product -rrb- .