Dear cadenz2,

about open vs closed chain exercises in patellofemoral rehab. I think the "traditional wisdom" is that closed chain exercises are the way to go for a variety of reasons. These include more simultaneous activation of the quadriceps muscles (therefore better patellar tracking), supposedly lower patellofemoral joint stress, and because closed chain exercises are generally much more functional than open chain.

However closed chain exercises of the knee such as squats, step ups and lunges are much more complex movements, involving multiple joints and there is a great deal of potential for other muscle groups to compensate for weakness or inactivity in the quadriceps. I'd say this is the case with your patient given given he has been "rehabbing" for a couple of months but is still only grade 2 in his quads.

I wouldn't think that open chain exercises would be contraindicated in your patient. Cohen et al (Am J Sports Med. 2001 Jul-Aug;29(4):480-7) found little difference between patellofemoral joint stress in open and closed chain quadriceps exercises, and I think especially when you consider the amplitude of contraction we're talking about here and the fact it is now months since the surgery, I think there is little risk of damaging his patellofemoral joint cartilage.

My suggestion would be to perform exercises in side lying with a low-friction board underneath his leg. Otherwise you could always eliminate gravity by getting him in a pool...

Also I think EMG biofeedback and even EMG triggered muscle stimulation could be very useful with this guy.

As his strength improves you can progress to more functional, closed chain exercises. EMG biofeedback can still be very usefull in that phase in order to work on VMO co-ordination, especially given his mal-alignment problems.

If he is getting a lot of pain with open chain exercises I would assess the position of the patella, try taping, lateral retinaculum stretches etc and see if you can reduce it.

By the way how is the swelling now? Even a mild amount of effusion can reduce quadriceps EMG activity, and this could also be a factor.

Hope this helps.
bmc