A client recovering from plantar fascitis, recently inquired about incorporating some leg work into his routine that did not involve standing or bearing weight on the affected foot. "You are probably thinking of some of the "open chain" leg machines we have when you first enter the gym. Open chain meaning, your feet are not connected to the floor while loading your lower limbs. Open chain exercises put undue stress on your joints, and eliminate vital sensory input from your feet being in contact with the ground. Aside from being contra indicative for preexisting joint issues, they really arent good for anyone. Beyond selling memberships, these machines are pretty worthless. They gained some popularity with the weight training boom in the 70s, spearheaded by body building (lots of aesthetically isolating, dysfunctional movements) Statistically, more people are hurt each year using machines than free weights. They force you into a one size fits all plane of motion and can mislead normal proprioception as you just go with the flow. The science behind training is shifting towards more functional, multi-muscle, multi-joint movements that simulate and reinforce real world activity or sport. Typcally leg extension/curl, and inner outer thigh machines isolate muscles that perform better in unison and should not be isolated. You also are nt burning alot of calories when performing these movements."