Knee Pain When Walking – Is It All In The Shoes?

We all take our ability to walk for granted until we are set back by crippling pain. The average American walks 7000-13000 steps per day.1 Over your lifetime, that’s a lot of steps! Each one of these strides applies pressure to our lower limbs and it all starts at the foot. The way in which the foot interacts with the ground can have a major influence on the stress applied to upstream joints, especially your knees. Consequently, the type of shoe you wear can influence any nagging knee pain when walking.

How Can a Shoe Reduce Knee Pain When Walking? 

There are several ways in which shoes modify our normal walking pattern. The most common feature you hear about in shoes is the amount of cushioning. Spring-like shock absorbers, foam insoles, gel insoles, and many other features have all been marketed by shoe companies to help cushion your joints. The idea is that shoe cushioning, similar to how an airbag system works in a car, helps dampen the impact on the leg as the foot hits the ground. As a result, knee pain when walking is reduced.

Shoe Cushioning Spectrum for walking related knee pain

Shoes can also redistribute the load from walking to different parts of a joint, or to a different area of your body entirely. For example, insoles with built-in medial or lateral wedges allow one side of your leg to bear more load than the other. The “heel lift” in a shoe (the height difference between toes and heel) can cause more weight to be distributed to the knees when walking. Lastly, footwear can change your walking behavior. A good example of this is barefoot walking, which surprisingly causes very little strain on your joints. This is because, while walking barefoot, you will tend to take smaller steps or walk at a slower speed. Both of which decrease joint loading.2 Some researchers suggest that barefoot contact with ground engages innate muscle reflexes that serve to provide stability and dampen joint strain.3

Your Footwear and Knee Pain

Shoe styles range from bulky orthopedic shoes all the way down to minimalist sandals such as flip flops. Chances are the footwear you are using falls somewhere between these extremes. So the question is, if you want to lessen your knee pain should you go for a shoe that provides maximum stability and cushioning? Many would say yes! Experts typically recommended shoes with “shock absorbing properties” and “arch support” for pain related to knee arthritis.

Despite healthcare professionals commonly recommending rigid, stable shoes with ample cushioning, there is little to no evidence to support this idea. Surprisingly, research in this area indicates that the absence of these features may actually be better for the knee.4 It turns out that walking barefoot results in the lowest joint loads on the knee.3,5 Minimalist shoes that attempt to simulate the barefoot experience, have been shown to reduce knee joint loading by 8% relative to their larger more cushiony cousins.3,5

– Barefoot walking loads the knee less than walking in shoes. 
– Minimalist shoes attempt to replicate barefoot walking patterns.


Walking – Shoes to Avoid 

High Heel Fashion Shoe cause knee pain when walking

We all like to be fashionable and wear shoe styles that make us feel great. However, there is one feature often present in shoes that should be avoided at all costs, especially if you are regularly walking long distances. Shoes with a heel higher than 1.5 inches dramatically increase the stress placed on your knees.6 Many people working in white collar environments wear high heel footwear on a daily basis. Shoes with a flatter sole may be more appropriate for daily wear, particularly for those that are walking and standing frequently. One exception to keep in mind is that flat shoes may not be optimal for those who often work in squatting positions (ex. mechanics and welders).

– Shoes with a high heel increase knee stress while walking

Knee Force Graph: Low versus High Heel Shoes
Figure 1: Profile of a single step or foot contact during normal walking.7 Peak stress placed upon the knee is highest at all points for a moderate heel shoe, while much lower for flatter shoe. 

Walking with Painful Knee Arthritis

There are a variety of special orthopedic shoes and insoles designed specifically for those suffering from knee arthritis. These shoes typically have one or more of the following features:

Rockers 

Rocker Walking Shoes for Knee Pain

Rocker shoes have a curved structure that allows the foot to strike the ground more evenly. As your heel hits the ground, rather than sudden breaking, the curved bottom of the shoes allows weight to smoothly roll to the forefoot. Since the load of each step is distributed over a larger period of time, the peak impact is reduced. Rocker shoes have been shown to reduce knee strain in most people with knee osteoarthritis.8 However, due to the curved nature of the soles, some may feel unbalanced when walking. Consequently, those already experiencing balance issues while walking should consider other options.

Offloading Wedges

Offloading Wedges for Knee Pain

Shoes and insoles can be designed to redistribute joint load to one side of the knee or the other. In doing so, less pressure is applied on the injured side of the knee at the expense of more pressure being applied on the non-injured side. Offloading wedges, change the angle of the foot, skewing knee loading laterally inward or outwards. OARSI (International Osteoarthritis Research Society)  recommends wedged insoles and shoes for those suffering from medial or lateral knee osteoarthritis.9 Despite this, it is still an open question as to whether or not wedged shoes actually reduce knee pain. Some research suggests that they provide little benefit after six months and two years of regular use.10

Variable Stiffness Soles 

Variable Stiffness Sole Shoes for Walking related knee pain

Variable stiffness shoes affect knee loading in the same manner as wedges. The stiffer side of the shoe takes more of the impact than the softer side. This translates to less load on the injured side of the knee and more on the non-injured side. Relative to normal footwear, a 4.7% decrease in lateral knee loading can be achieved with variable stiffness shoes.11t Despite the favorable change in knee loading, not everyone will see improvement in their symptoms using this type of shoe. It is likely that only those with extremely severe arthritis will reduce their knee pain when walking.11

Despite all the effort invested in shoe technology research, the evidence for their benefit to those with knee arthritis is underwhelming. The force redistribution mechanism(s) found in most of these shoes are only designed for individuals with either lateral or medial compartment knee arthritis. Those suffering from either lateral or medial knee osteoarthritis make up less than 6% of patients.12 Patients with multi-compartment osteoarthritis or patellofemoral osteoarthritis are unlikely to experience any benefits from these types of shoes. If this describes you, check out other treatment options here: Guide to Treatment Options for Severe Knee Arthritis

Severe Knee Osteoarthritis 

While not proven, it is possible that shoes are part of the problem, not the solution. Some research suggests that spending more time barefoot rather than in normal footwear may reduce the frequency and intensity of pain flare-ups associated with knee arthritis.13 This is likely because walking barefoot leaves the foot vulnerable causing you to “tread lightly”. 

– Most orthopedic shoes slightly unload the knee in a manner that is appropriate for those suffering from isolated medial or lateral knee arthritis only. 

– Only a small subset of patients improve their symptoms while wearing orthopedic shoes instead of their normal footwear. 

– Walking barefoot may be the most knee-friendly way to ambulate for those with arthritis.

Alternative Solutions for Pain During Walking

Unloader knee brace for knee arthritis

Footwear solutions are aimed at reducing peak knee load and distributing load to uninjured areas of the knee. While this can be helpful in specific situations and may reduce knee pain when walking for some patients, it is limiting because the total load on the knee joint remains more or less the same. A more complete solution is tri-compartment unloading, a process by which pressure in all three areas of the knee joint is reduced. 

There are a variety of methods to achieve tri-compartment unloading such as canes, walkers, and more convenient solutions such as unloader knee braces. These braces are arguably a little more unsightly than orthopedic footwear, but they provide significantly more benefit. Specialized braces that provide tri-compartment unloading can reduce pressure in the knee by up to 64% and can help tremendously when ascending and descending stairs.14 If you are suffering from knee pain when walking, knee bracing could be a promising solution.

References 

  1. Tudor-Locke, C., & Bassett, D. R. (2004). How many steps/day are enough?. Sports medicine, 34(1), 1-8.
  2. Shakoor, N., Lidtke, R. H., Sengupta, M., Fogg, L. F., & Block, J. A. (2008). Effects of specialized footwear on joint loads in osteoarthritis of the knee. Arthritis Care & Research: Official Journal of the American College of Rheumatology, 59(9), 1214-1220.
  3. Shakoor, N., Sengupta, M., Foucher, K. C., Wimmer, M. A., Fogg, L. F., & Block, J. A. (2010). Effects of common footwear on joint loading in osteoarthritis of the knee. Arthritis care & research, 62(7), 917-923.
  4. Paterson, K. L., Wrigley, T. V., Bennell, K. L., & Hinman, R. S. (2014). A survey of footwear advice, beliefs and wear habits in people with knee osteoarthritis. Journal of foot and ankle research, 7(1), 43. 
  5. Trombini-Souza F, Kimura A, Ribeiro AP, Butugan M, Akashi P, Pássaro AC, Arnone AC, Sacco ICN: Inexpensive footwear decreases joint loading in elderly women with knee osteoarthritis. Gait Posture 2011, 34:126–130.
  6. Kerrigan, D. C., Johansson, J. L., Bryant, M. G., Boxer, J. A., Della Croce, U., & Riley, P. O. (2005). Moderate-heeled shoes and knee joint torques relevant to the development and progression of knee osteoarthritis. Archives of physical medicine and rehabilitation, 86(5), 871-875.
  7. Paterson, K. L., Bennell, K. L., Wrigley, T. V., Metcalf, B. R., Kasza, J., & Hinman, R. S. (2017). Effects of footwear on the knee adduction moment in medial knee osteoarthritis: classification criteria for flat flexible vs stable supportive shoes. Osteoarthritis and cartilage, 25(2), 234-241.
  8. Madden, E. G., Kean, C. O., Wrigley, T. V., Bennell, K. L., & Hinman, R. S. (2017). How do rocker-soled shoes influence the knee adduction moment in people with knee osteoarthritis? An analysis of biomechanical mechanisms. Journal of biomechanics, 57, 62-68.
  9. Zhang, W., Moskowitz, R. W., Nuki, G., Abramson, S., Altman, R. D., Arden, N., … & Dougados, M. (2008). OARSI recommendations for the management of hip and knee osteoarthritis, Part II: OARSI evidence-based, expert consensus guidelines. Osteoarthritis and cartilage, 16(2), 137-162.
  10. Pham, T., Maillefert, J.F., Hudry, C., Kieffert, P., Bourgeois, P., Lechevalier, D. et al.Laterally elevated wedged insoles in the treatment of medial knee osteoarthritis. A two-year prospective randomized controlled study. Osteoarthritis Cartilage. 2004; 12: 46–55
  11. Erhart, J. C., Mündermann, A., Elspas, B., Giori, N. J., & Andriacchi, T. P. (2010). Changes in knee adduction moment, pain, and functionality with a variable‐stiffness walking shoe after 6 months. Journal of Orthopaedic Research, 28(7), 873-879.
  12. Duncan, R. C., Hay, E. M., Saklatvala, J., & Croft, P. R. (2006). Prevalence of radiographic osteoarthritis—it all depends on your point of view. Rheumatology, 45(6), 757–760.doi:10.1093/rheumatology/kei270 
  13. Atukorala, I., Pathmeswaran, A., Batuwita, N., Ratnasiri, V., Rajapaksha, N., Wijayaratne, L. S., … Hunter, D. J. (2019). Is being barefoot, wearing shoes and physical activity associated with knee osteoarthritis pain flares? Data from a Sri Lankan cohort. Osteoarthritis and Cartilage, 27, S403–S404. doi:10.1016/j.joca.2019.02.406 
  14. McGibbon, C. & Mohamed, A. Knee Load Reduction From an Energy Storing Mechanical Brace. Canadian Society for Biomechanics (2018)