While many advocate a functional approach to exercise for patients with patellofemoral pain, isolated muscle weakness can lead to bad compensation patterns in weight-bearing exercise if the strength impairment is not addressed first. The eternal open chain vs. closed chain, isolated versus multi-joint exercise argument is derivative. Why set up an either-or unnecessary forced choice?
1. Measure. Perform instrumented muscle strength tests of the knee extensors and flexors, and the hip abductors. If you do not have access to an electromechanical dynamometer, then the use of a hand-held dynamometer with straps is a good substitute with adequate reliability and established MCIDs.
2. When weakness is identified as an impairment, treat it with progressive, resisted, isolated open chain exercise in a position or arc that does not reproduce the patient’s patellofemoral pain symptoms. Manual resistance can be used to identify the painless positions or arcs.
3. Measure again.
4. Incorporate the newly acquired strength into progressive functional training and return to activity.
For all progressions, isolated strengthening, functional progression and return to activity, follow the established soreness rules from Fees and colleagues and Adams and colleagues:
- If there is soreness during warm-up that continues, then the action should be 2 days off and drop down one level.
- If there is soreness during warm-up that goes away, then the patient should be to stay at the same level of exercise that led to the soreness.
- If there is soreness during warm-up that goes away then returns during the exercise session, then the patient should be given 1 day off and dropped down one level.
- If there is soreness after lifting, but not muscle soreness, then the patient should be given 1 day off and should not advance to the next level of exercise.
- If there is no soreness, then the patient can advance one level each week or as instructed.
Soreness is operationally defined as the patient’s patellofemoral pain, not muscle soreness, which is both desired and expected. Let’s all move past the open chain closed chain false choice into a rational, evidence-based approach to this complicated problem.
Adams D. J Orthop Sports Phys Ther. 2012;doi:10.2519/jospt.2012.3871.
Fees M. Upper extremity weight-training modifications for the injured athlete. A clinical perspective. Am J Sports Med. 1998;26:732-742.
Thorborg K. Knee Surg Sports Traumatol Arthrosc. 2013;doi:10.1007/s00167-012-2115-2.
- Lynn Snyder-Mackler, PT, ScD, FAPTA, is an Alumni Distinguished Professor of Physical Therapy with a joint appointment in the Departments of Kinesiology and Applied Physiology and Biomedical Engineering, University of Delaware, Newark, Del. She can be reached at email@example.com.
- Disclosure: Snyder-Macklerhas no relevant financial disclosures.