May 14, 2009
Footwear and Knee Pain
While walking, weight is transferred from the heel to the outer foot and and then to the inner side of the foot (the ball of foot) before toe-off.
Pronation is the natural inward roll of the foot that occurs as the arch collapses (like a spring to absorb shock) between the time the heel contacts the ground and toe-off. The lower leg also rotates slightly inward during pronation. Pronation is normal and necessary for the foot to adequately absorb shock.
What is Overpronation
Overpronation is an excessive inward roll of the foot while walking or running.
Overpronation causes excessive internal rotation of the lower leg and knee and can affect the alignment of entire lower body. Overpronation places extra strain on the lower body and can cause foot pain (pain in arches, heels and ankles), knee pain, leg pain, and lower back pain.
Overpronation can cause or contribute to poor knee tracking and knee pain.
Overpronation can cause or contribute to poor knee tracking. The kneecap slides over a groove on the thighbone as your knee bends and straightens. When the kneecap is pulled to the left or right of the groove while walking or running, it causes friction and knee pain on the underside of the kneecap. Poor knee tracking (runners knee) is most often caused by a weakness or imbalance of the quadriceps, but the excessive rotation of the lower leg and knee from overpronating can also cause or contribute to poor knee tracking and knee pain.
Often, mild overpronation is not the main cause of knee pain caused by poor knee tracking, but a contributing factor
Severe overpronation often causes knee pain. While the lower leg is internally rotating inwards, the upper leg is turning in the opposite direction, causing a slight twisting of the knee joint that leads to irritation and knee pain.
Signs of Overpronation
Excess wear on the inner sides of the shoes, often the inner sides of the heels, is a sign of overpronation. With wear, the heels of the shoes may also tilt inwards – towards each other.
Other signs of overpronation are heels that lean inwards and kneecaps that turn inwards while standing. Knee pain that develops gradually during activity and gradually dissipates with rest is often a sign the kneecaps don’t track properly. Knee pain caused by poor knee tracking can be caused or aggravated by overpronation.
Arch height is a major factor in determining the amount of foot pronation. Flat feet often cause overpronation but not all overpronators have flat feet. Those who have feet with high, inflexible arches often underpronate.
Morton’s foot, or Morton’s toe can cause overpronation. Morton’s foot (Big toe shorter than second) is common. If the big toe is shorter, the foot rolls inward further before toe-off.
Footwear for Overpronation and Knee Pain
Motion control and stability shoes reduce overpronation to prevent knee pain.
Motion control shoes and stability shoes incorporate support features into the shoe. Shoes with adequate medial / arch support and firm heel counters help control overpronation. Some shoes also have side posts for extra lateral support. Firm midsoles reduce pronation and protect the knees from lateral stress. The inner side of the midsole may be made of a denser material (dual density midsoles) to reduce the amount of pronation. The shape of the shoe is also important in controlling gait problems (overpronation or underpronation). Straight shaped shoes reduce overpronation.
Stability shoes are lighter and more flexible than motion control shoes. Stability shoes are usually adequate for those who overpronate mildly. Motion control shoes are for those who overpronate severely. A heavy person who overpronates will need a heavier, more supportive shoe than a light person with the same degree of pronation.
Adequate foot support for overpronators can relieve or prevent foot pain, knee pain and lower back pain.
Shoes with Adequate Medial / Arch Support Controls Overpronation to Prevent and Treat Knee Pain:
Adequate medial (arch side) support is especially important for those with overpronation. This prevents the foot from rolling inwards excessively as you walk or run.
Motion control shoes or stability shoes with good medial support are available. Arch supports / orthotics can be inserted into most casual shoes. However, because reducing pronation depends on proper heel support as well as arch support, arch supports should be used in shoes with firm heel counters. The shoe should also have a firm midsole. The shoe must also be deep enough to accommodate the arch support inserts. Custom shoe inserts (orthotics) may be necessary for those with severe overpronation.
When knee pain around or under the kneecap is caused or partly caused by overpronation, an arch support often provides more knee pain relief than a knee brace.
Shoes with Firm Heel Counters Control Overpronation to Prevent and Treat Knee Pain:
A rigid heel counter (insert in back of heel of shoe to reinforce the heel cup that wraps around heel) supports and stabilizes the heel to reduce overpronation. The heel cup should fit snugly enough to prevent slippage and prevent twisted ankles.
Shape of the Shoe and Pronation:
(Look at the shape of the bottom of the shoe – some are straight, some are curved, some semi-curved)
*Straight shaped shoes work best for controlling severe overpronation and for those with flatter arches.
*Slightly curved shaped shoes accommodate an arch, and are good for people who have a mild problem with overpronation.
*Curved shaped shoes work well for those who underpronate.
Knee Pain, Underpronation, and Footwear
Underpronation means the foot doesn’t pronate enough to adequately absorb shock. This can lead to pain in any area of the lower body – from the feet (especially the heels) to the knees to the lower back. Underpronators usually have high, inflexible arches but not everyone with high arches underpronates.
Footwear for Underpronators:
Well cushioned shoes provide the extra shock absorption needed by underpronators. Curved shaped shoes (look at bottom of shoe) and flexible shoes help to encourage pronation.
Adequate Cushioning / Shock Absorption and Knee Pain
Adequate shock absorption not only prevents foot pain, but pain throughout the rest of the body – foot pain, knee pain, and lower-back pain.
Adequate cushioning is important for anyone who does a lot of walking. Footwear with adequate cushioning is especially important when walking on pavement or any hard surface. The impact of the feet hitting the ground is transmitted up the through the knees, legs, and lower back. Shoes with cushioning help absorb the impact of the feet striking the ground while walking, running or jumping. Shoes with shock absorbing soles not only prevent foot pain, but prevent knee pain and lower-back pain
*If you overpronate, highly cushioned shoes may not provide adequate support.
Shoes that are very padded can worsen overpronation. Firm midsoles give more support, reducing lateral stress on the knee and knee pain. There are motion control shoes that combine high cushioning with adequate support but are often bulkier, heavier shoes.
High-heeled Shoes and Knee Pain
The damage and pain inflicted from wearing high-heels is most often to the feet, but wearing high heels is also a common cause of lower back pain and knee pain.
High heels throw the body forward and increase pressure underneath the kneecap. High-heeled shoes with wider heels are easier on the feet but cause just as much knee pain as stilettos. Some of the harmful effects of wearing high heels are immediate, but some problems develop very gradually. Over time, high heels may contribute to knee osteoarthritis.
Heels one half to three quarter of an inch are ideal. Heels that are too low (under a half-inch) may not provide adequate shock absorption.
High heels throw your entire body out of alignment and can cause foot pain, knee pain, and lower back pain.