BY Tanya Buchan
After a knee injury, recovering the functional performance and strength of the lower extremity is an important goal for rehabilitation and recovery. Some recent studies have highlighted the importance of addressing any strength deficits after knee injury or bout of knee pain to possibly prevent the development of early degenerative changes in the knee joint, and improve the knee related quality of life measures in the future.
In a study of ACL reconstructed patients by Culvenor et al (2016), those that could do at least 22 single leg rises had better knee-related quality of life at one and three years post-op than those that couldn’t do 22 repetitions. When we talk about knee-related quality of life in this way, it is a subjective measure of knee confidence, modification of lifestyle, awareness of knee symptoms and the general difficulty because of the knee.
So the study would suggest that if you were able to perform more than 22 single leg rises now, then you have a much reduced chance of struggling with those particular measures in one year and again in three years time. It may also be important to have functionally strong legs to combat the onset of knee osteoarthritis.
In another study of ACL injured people, Koos eta al concluded that a reduced functional performance in the lower extremity (inability to do 22 single leg rises) might predict the development of radiographic knee osteoarthritis in the future.
But what if you haven’t suffered a significant knee injury like an ACL reconstruction? Although these studies are directed at ACL patients, the ability to perform single leg squats can improve physical performance in all aspects of life for everyone.
The ability to perform single leg squats can improve physical performance in all aspects of life for everyone.
Test yourself and see how many you can do.
Stand in front of a bench or chair that is a height that comes to just behind your knee crease.
Using one leg only, stand from a sitting position without using your arms or throwing your trunk forward.
From standing, lower yourself to gently sit back on the chair/bench without losing your balance. Don’t sit back down too heavily or stay too long because you have to stand back up.
Control both the up and down movement so that you maintain a consistent tempo and use your muscles (don’t flop!).
You should aim to have no more than a two-repetition difference between legs and be mindful of your quality - don’t let your knee collapse inwards during the movement.
If you can achieve 22 or more good quality repetitions on both legs (without more than a two rep difference between sides) than you are doing well with your knee strength, control and quality. Keep it up!
If you didn’t quite get 22 repetitions or had one side that was much better than the other, than it may be a good idea to work on your knee stability and leg strength to protect your knee joint for the future. This appears to be even more important if you suffer from knee pain, have had a knee injury or knee surgery within the last 12 months or are aged between 20-40 years old.
Remember, it is never too late to improve the functional performance of your lower extremity with some good quality strength exercises like squats, lunges and single leg squats. Build up some knee strength and muscle bulk for the future health and quality of life for you and your knees.
If an improvement in leg strength is something you would like to achieve or knee pain is holding you back from reaching your exercise, sport or life goals then get in touch with us here at Intune Sports and Health - The Performance People.
Thanks to Mick Hughes for the references.
Culvenor AG., Collins N.J., Guermazi A., Cook J.L., Vicenzino B., Whitehead T.S., Morris H.G., Crossley K.M. (2016). Early Patellofemoral Osteoarthritis Features One Year After Anterior Cruciate Ligament Reconstruction: Symptoms and Quality of Life at Three Years. Arthritis Care & Research Vol 68 No 6 pp 784-792
Thorstensson C.A., Petersson I.F. Jacobsson L.T.H., Boegard T.L. Roos E.M. (2004). Reduced functional performance n the lower extremity predicted radiographic knee osteoarthritis five years later. Annauls Rheumatology Disorders 63: 402 - 407
Brodie Gardner has a Masters in Exercise Physiology, Honours in Sports Science and competes as a professional triathlete. He has a long history working with elite athletes and has provided consultation services to numerous Australian sporting associations.