My Athletic Trainer/PT Couldn't Answer This

Our user asked: "I have been rehabing multiple areas of my body (upper and lower extremities) at one time which got all out of whack when I slipped on a bathroom rug last Oct., then became even worse after I continued to walk around for 6 months before going to be evaluated by PT. I have had 90-minute 2X/wk appointments with a sports trainer after a sports trainer who has split up my appointments doing strength training and MFR. Since I had a long-standing history of right SI problems which was worsened by this fall, he began with that, and has just moved on as I have improved. My neck was part of the problem, too, in all directions, and he took me through many unwindings that have been literally amazing. There's only one time today he was stumped (today), and it was when I asked him something about a piece of equipment he puts patients on every day. He and the other therapists there said that their equipment was so old (but still very usable!) that no one had the owner's manual anymore that they could look up my answer for me. I have been doing supine squats, flat on my back as always and recently with just one leg, on this piece of equipment they call a Shuttle. It has 5 power bands on it. When I started I could only use 2 power bands and could barely push it back with both legs, at a number setting on a slider behind where a patient puts there feet. Now I use 5 bands and today he put it on number 5, which was HARD with one leg, but doable for 4 sets of 10. What kind of weight does that translate to? I asked him what the numbers meant on the slider bar, as well as the power band, and he couldn't tell me other than to tell me that I was getting stronger! I wanted to know how much stronger. By the way, I have RSD/CRPS in 4 extremities these last 14 years and have both a cervical (implanted in 2000) and lumbar (implanted in 2005) spinal cord stimulator. Thank you."

Ask a PT Response: "I am familiar with the Shuttle and remember using it at a clinic that I worked at when training in college. We primarily used it to train the quadricep and calf muscles. We utilized the numbers on the slider bar as a way to objectify how far an individual could push off from the kickplate (distance traveled away from the kickplate) when having the patient perform jump/plyometric drills. Obviously the stronger they got the more force they could generate and the farther they could go. As far as how much laod is being applied, I found the manual on line at: http://www.shuttlesystems.com/manuals/MVP_Operating_Manual.pdf . This Shuttle looks a little more advanced than the Shuttle I remember using but the theory appears to be the same. According to the manual if you use 8 cords and your stroke length is 13 inches (8 x 30lbs), the total load at that point would be 240lbs. You can figure the load you are performing by looking at the graph in the manual and doing the math. As far as how much stronger you have gotten, your PT/ATC can perform manual muscle testing or have you perform functionally related tasks which could be objectified and compared to later on down the road as well. I hope this helps. Thanks for using CyberPT."