Approximately 25% of adults suffer with frequent knee pain, pain that is severe enough to limit function, mobility, and negatively impact quality of life, whilst osteoarthritis is rated as the most common cause of knee pain in people aged 50+ (Nguyen et al, 2011). Obesity is also a strong indicator for increased knee pain, as it has been hypothesised that for every 1kg of additional body weight, 4kg of mechanical load is distributed through the knee. Even moderate levels of weight loss (9% of total body weight) has been shown to improve both knee cartilage quality and quantity (King & March, 2013). Additionally, the Australian Institute of Health and Welfare states that there has been a 32% rise in the rate of total knee replacements (TKR) over the 10 year period from 2004 to 2014. But why the increase? Can it be simply be attributed to both an ageing and more overweight population? How can you decrease your risk of a TKR later in life by having healthier knees NOW?
Quite simply, the heavier we are, the greater joint load we will experience. This is no more true of the major supportive and load-bearing joints of the body; the lumbar vertebrae, hips, knees and ankles. No amount of joint mobility can off-set the excess weight that negatively impacts the supporting structures of these joints. Additionally, the prevalence of an inflammatory internal environment (read The Evolving Role of Obesity in Knee Osteoarthritis https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3291123/ to learn more on this) so common amongst the overweight and obese, only further leads to negative joint health and the increased risk of osteoarthritis. But if knee joint pain is too great, how can someone exercise at an intensity great enough to stimulate weight loss?
Hydrotherapy is a great exercise modality for people who both carry excess weight and suffer with debilitating knee pain. The buoyancy of the water is effective at de-loading the joints, as well as adding resistance to movement to encourage increased muscle endurance, elevated cardiovascular response, and metabolic conditioning (fat burning and weight loss). Being in the water has also been shown to improve circulation, decrease nervous system sensitivity to pain, and reduce stress and anxiety.
Any exercise that will promote an elevated heart rate and not place additional load or impact through the knee joint can also be prescribed during this time.
With any weight loss plan, specialist dietary advice must be sought. At Restart we welcome Zara from EatSmart Nutrition (contact Zara now at email@example.com to get your diet on track and subsequently improve joint health) to provide education and individualised meal plans to assist towards decreased body weight and body fat. Adequate hydration is also a major player in optimal joint health and musculoskeletal function. Achieving optimal diet and hydration can only positively impact on the load-bearing joints of our body.
Remember that for every 1kg loss in body weight, our knees are much happier to the tune of approximately 4kg less load being distributed down to them!
Ankle and foot mobility…
I met a Podiatrist named Tim Bransdon recently who described the feet as “4WD springs for the body”. I think this is a great way to think of our feet, rather than something that we neglectively shove into a shoe for 10 hours a day and think that they’ll look after themselves. When we are being encouraged to take 10,000+ steps per day, a healthy foot and ankle is integral to absorbing the forces and shocks of landing, stepping and decelerating, much like the suspension springs of a 4WD.
The footwear we choose to house our feet in can also heavily dictate our foot health. When buying a shoe, look out for the following attributes:
– heel pitch: the greater the heel pitch (heel raise), the greater the detrimental effect on the function of the foot. It also leads to shortening of the Achilles tendon and calf muscles, which can lead to a number of negative lower limb conditions;
– cushioning: too much cushioning between your foot and the floor can significantly reduce the feedback our feet are able to acquire from the world beneath us. The 200,000+ nerve endings are designed to provide endless amounts of feedback to our brain; if shoe cushioning is too thick, this feedback is inhibited;
– shape: next time you take your shoes off, observe the widest part of your foot. In most cases, the widest part of the human foot is at the toes. More often that not however, our shoes taper into a triangle shape at the toe, thus compressing our toes and inhibiting big toe function, which is integral to optimum foot function and human movement;
– flexibility: our foot, compromised of 33 joints and 20 muscle groups, is designed to move, yet often we ‘imprison’ them in heavy, rigid, and immobile shoes. A shoe must be flexible enough to allow our feet to move as they are designed to!
Addressing poor foot mechanics, improper big toe function, and limited ankle mobility (how’s your ankle mobility? Book in for an Injury Risk Assessment today at https://www.restartep.com.au/injury-risk-assessment/) is a great way to increase your chances of a healthy knee joint.
Patellofemoral Syndrome (PFS)…
A common condition that we encounter at Restart is called ‘Patellofemoral Syndrome’. There is no one factor that is deemed responsible for this potentially painful condition, but from experience working with clients, on the most part it stems from an imbalance in soft tissue strength in the structures surrounding the knee cap. In typical presentations of this condition, we observe weakness in the Vastus Medialis Obliques, or VMO (muscle that runs along inside of thigh into the tendon above the knee cap), which leads to decreased stabilising force and muscle activation mis-timing at the knee joint (Sevinksy, 2010). In addition to this, we see tightness in the Ilio-tibial Band (ITB), or lateral thigh soft-tissue, which affects the patella’s ability to track optimally in the intercondylar notch during knee flexion and extension movements.
This condition is usually positively impacted by using self-massage techniques on the soft tissue of the outer thigh (see pic #4 below), and checking for adequate muscle activation patterns throughout the VMO and supporting structures.
Points #4 and #5 very much tie in together. During a squat or dynamic movement, such as walking, lunging, hopping, or jumping, it is important to note how the ankle, knee and hip communicate to each other. By this I mean do they communicate effectively and maintain alignment, or is there evidence of miscommunication and resulting misalignment?
A 2005 study by Hewett and colleagues concluded that increased femoral valgus (knock-kneed, as demonstrated by Kate below in pic #6B) is a predictor for decreased neuromuscular activity and anterior cruciate ligament injury in female athletes. Simply put, when knees collapse inwards during activity, whether it be due to poor foot mechanics or poor Gluteus muscle control, you are at a greater risk of knee injury.
Corrective exercises (see pics #7 & #8 below) are proven to be beneficial towards overcoming this common movement fault!
In today’s society of sedentary living, all too often we see client’s present with poor, and even non-existent Gluteus muscle activation/control. Believe it or not, there is even a condition called ‘Dormant Bum Syndrome’ which details this common condition. The Gluteus maximus muscle is the largest muscle in the body, and is a big player in functional movements such as walking, jogging, climbing stairs, and maintaining an erect posture, to name a few. In conjunction with the external hip rotator muscles, sitting down for extended spells leads to inadequate muscle control and can lead to poor hip stability and therefore poor hip –> knee –> ankle alignment. In such cases, guess which joint often takes the brunt of this dysfunction and begins to pain…? You guessed it, the knee.
Pictures 7 & 8 below are examples of exercises to target both the Gluteus and external hip rotator muscle groups, and when done correctly, can take your hip control from weak and unsteady to strong and steadfast! The resulting benefits on knee health are often significant.
The above is a brief summary of rectifying what can often be a complex combination of dysfunctional movement patterns, the symptom of which being what brought you here in the first place: unprovoked, debilitating knee pain. There are countless other treatment modalities to consider when treating knee pain, including hip flexor and quadricep muscle length, posterior chain (notably Hamstring) function, core control, and segmental coordination.
Getting the 5 above knee rehabilitation techniques right are a tried and tested way to overcoming debilitating knee pain!
Sowers, M.R., & Karvonen-Gutierrez, C. (2010) The evolving role of obesity in knee osteoarthritis. US National Library of Medicine, 22, 533-537.
King, L., March, L., & Anandacoomarasamy A. (2013) Obesity & osteoarthritis. US National Library of Medicine, 138, 185-193.
McIlveen, B., Robertson, V. (1998) A Randomised Controlled Study of the Outcome of Hydrotherapy for Subjects with Low Back or Back and Leg Pain. Science Direct, 84, 17-26.
Nguyen, U.D.T, Zhang, Y., Zhu. Y, Niu. J., Zhang. B., Aliabadi. P., Felson D. (2011) Increasing Prevalence of Knee Pain and Symptomatic Knee Osteoarthritis. US National Library of Medicine, 155, 725-732.
Sevinsky, S. Patellofemoral Syndrome: Evaluation & Management. Retrieved from http://scottsevinsky.com/pt/presentations/inservice_pfs.pdf
Hewett, T.E., Myer. G.D., Ford, K.R., Heidt Jnr, R.S., Colosimo, A.J., McLean, S.G., van den Bogert, A.J., Paterno, M.J., Succop, P.(2005) Biomechanical Measures of Neuromuscular Control and Valgus Loading of the Knee Predict Anterior Cruciate Ligament Injury Risk in Female Athletes. Mechanical Engineering Faculty Publications, 33, pages unknown.