Brian Schiff’s Blog
Injury Prevention, Sports Rehab & Performance Training Expert
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In many cases, my clients are unable to perform traditional strengthening exercises for the lower body due to anterior knee pain or weakness. Beyond loading, using the time under tension principle is a great way to add strength for those who cannot squat, lunge, etc. Below are two great videos of isometric ‘go-to’ exercises that will help improve strength and functional capacity in those who are otherwise limited in their workouts.
I hope you can use these exercises or some variation of them to increase strength and overcome injury and dysfunction.
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.
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……
For those who know me well, it is safe to say I am an “ACL geek” of sorts. I love studying, reading and searching for the best way to rehab and prevent these injuries. As I have grown in the profession, I have become increasingly concerned with articular cartilage damage and the long term effects it has on our young athletes.
Perhaps I am getting more concerned as my knees aren’t getting any younger either (lol). Anyway, I truly believe we often underestimate how deleterious cartilage injuries can be long term. In addition, I feel we, as rehab and conditioning professionals, need to better understand how our training impacts the cartilage regardless of whether patients had a concomitant bone bruise with their ACL injury or not.
One of my favorite prehab exercises is a single leg hop and stick (see below)
I typically begin with an alternate leg approach (push off right and land on left) prior to initiating takeoff and landing on the same leg to teach proper landing mechanics. By now, we know increasing hip and knee flexion, as well as shifting center of mass forward reduces ACL strain and injury risk through a diminished extension moment.
However, what we may not know as much about is how an ACL reconstruction alters tibiofemoral joint mechanics at such a landing. I want to share some interesting information from a recent article in the September edition of The American Journal of Sports Medicine. The article by Deneweth et al. looked at tibiofemoral joint kinematics of the ACL reconstructed knee during a single-legged hop landing.
It is no secret that Americans are trying to stay more active well into their baby boomer years and beyond. The million dollar question is how will what you do today affect your joints down the road.
Scholars, scientists and medical experts do not seem to agree 100% on what is too much, but most tend to agree that excessive running, obesity, irregular or unusually intense activity (think weekend warriors here), muscular weakness and even decreased flexibility may all contribute to arthritis.
The New York Times recently ran a story about the cost of total joint replacement and suggestions on how people can be proactive to reduce the risk and debilitating effects of arthritis. Click here to read the article.
I think one of the most amusing yet ironic things about science is that it often contradicts itself. Obviously, we know being overweight increases stress on the load bearing joints. Most people would also knowingly acknowledge that improved strength and flexibility would make for healthier knees and hips.
The big question mark for me is impact loading, or simply the argument of whether to run or not to run. Some docs say no way. Others say yes. Yet others offer more ambiguous words on the subject. So, what do I think?
I honestly believe there may be no absolute answer. I am not convinced running on a treadmill is all that much better for you as some would suggest either. My body tells me blacktop surfaces are better than cement sidewalks, while the soft earth is better yet still. I use the treadmill in the winter and for speed work but if you run events too much treadmill work will let you down on race day as the body is ill prepared.
Much like exercise prescription, I think joint loading and tolerance is a very individual matter indeed. Biomechanics, posture, training history, medical history, repetitive movements, footwear, nutrition, body type, recovery, etc are just a few of the variables one must consider when passing judgment on exercise prescription and limits.
Beyond that, the best indication to reduce or remove an activity for a short bit or long term is obviously pain. But before doing so, one must correctly identify the source of the pain. At times, the pain may seem like a joint issue when in fact it could simply stem from poor muscle recruitment, lack of mobility or faulty movement patterns thereby subjecting joints to undue stress.
I say all this to say we must be careful in saying one should not do something definitively. Some folks run well into their 80’s without issues. Others break down after one endurance event. In the end, we must face facts. The human body is complex and no two people are exactly alike. I had left hip pain years ago that felt like arthritis. My orthopd told me the x-ray showed a few mild bone spurs and mild hip dysplasia.
His advice? Quit running. I did for 6 months and the pain did not subside. So, I began a progressive running program and changed up my strength training to more single leg based work. Guess what? My pain went away 100%. This tells me the impact itself was not likely the cause of my pain, but more likely a muscle imbalance that I overcame through more efficient strength training.
We must look at science, anecdotal findings and clinical experience to pull out general patterns and thoughts all the while continuing to use assessment, feedback and results to lead us to the best conclusion for each client, patient or athlete. You must use all this information to make the best decision for your situation as well.
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