It is common knowledge in the medical community that treating patellofemoral joint pain (PFJP) is one of the most frustrating and difficult tasks to complete as there appears to be no standard way to do so.  While clinicians strive to find the right recipe or protocol (I don’t believe there is just one by the way), researchers press on to find more clues.

A new article released in the April 2011 Journal of Orthopaedic & Sports Physical Therapy seeks to bring clarification to a particular exercise pattern commonly used in rehab circles.  The three exercises they looked at were:

  • Forward step-up
  • Lateral step-up
  • Forward step-down

In the study, the authors looked at 20 healthy subjects (ages 18-35 and 10 males/females) performing the separate tasks with motion analysis, EMG and a force plate.  The goal was to quantify patellofemoral joint reaction force (PFJRF) and patellofemoral joint stress (PFJS) during all three exercises with a step height that allowed a standard knee flexion angle of 45 degrees specific to each participant.

Key point:  Previous research has been done to indicate that in a closed chain setting, knee flexion beyond 60 degrees leads to increased patellofemoral joint compression and this may be contraindicated for those with PFJ pain or chondromalacia.  Also keep in mind that most people with PFJ complain of more pain descending stairs than ascending stairs.

patellofemoral-force

In the study, the participants performed 3 trials of 5 repetitions of each exercise at a cadence of 1/0/1 paced with a metronome.  The order of testing was randomized for each person.  The authors used a biomechanical model to quantify PFJRF and PFJS consisting of knee flexion angle, adjusted knee extensor moment, PFJ contact area, quadriceps effective lever arm, and the relationship b/w quadriceps force and PFJRF.

Now on to the results……

As you may have guessed, the front step-down (FSD) resulted in greater PFJRF and PFJS than the both the front step-up (FSU) and lateral step-up (LSU).  Other key things to note:

  1. The eccentric phase produced more PFJS than the concentric phase for all 3 exercises
  2. The mean +/- SD knee flexion angles at peak PFJS during concentric (ascending) phase were 73.4 +/- 9 degrees, 60 +/- 10 degrees and 59.2 +/- 6.4 degrees for the FSD, LSU and FSU exercises
  3. The mean +/- SD knee flexion angles at peak PFJS during the eccentric (lowering) phase were 69.2 +/- 6.7 degrees, 62 +/- 8 degrees and 59 +/- 6 degrees for the FSD, LSU and FSU exercises

The authors point out that the main contributor to elevated peak PFJRF during the FSD was the knee flexion angle.  Given this information, it is suggested that avoiding the FSD may be indicated in those with PFJP, or lowering the step height to more closely approximate flexion angles and replicate PFJRF and PFJS seen in the LSU and FSU should be considered.

In my experience, I tend to avoid the FSD altogether as a rehab exercise and instead focus on the eccentric phase of the LSU, which I tend to simply call a lateral step-down (LSD).  Staying lateral on the box (adjusting height according to the each client) allows clients and patients to achieve a more natural hip strategy, lower the peak quad moment, knee flexion angle and PFJ stress all the while strengthening the VMO in the terminal ranges of concentric and eccentric extension needed to promote optimal function.

Lateral Step-Down

Lateral Step-Down

Some may say that is not how one descends steps.  I totally agree. But, in order to restore that pain free mobility, we must first increase the threshold of the PFJ to certain eccentric loads and I find it often responds well to controlled lateral step-downs with flexion angles at or less than 60 degrees.  The other major component is addressing hip strength/stability, ankle mobility and any myofascial (namely IT Band) restrictions that impact frontal plane mechanics and ultimately may lead to abnormal lateral patellar tracking and premature wear of the lateral facet/lateral femoral condyle as well.

In the end, some patients can do a FSD without much pain, while others cannot.  The key to our success as fitness and rehab professionals is understanding what science tells us about joint structure, force application, loading patterns and biomechanics to better create and fine tune exercise interventions that train and restore proper function in those we serve.

If we eliminate imbalances and remove the painful stress long enough to restore tissue homeostasis, people will regain full function again.  Don’t be in a hurry and be willing to tweak the smallest things along the way to achieve success.  After all, it is the proper application of knowledge that brings about the best results over time.