The 8 common biomechanical categories used in the treatment of injuries are:
- Short Leg Syndrome (discussed here)
- Poor Shock Absorption
- Excessive Pronation
- Excessive Supination
- Tight Muscles
- Weak Muscles
- Miscellaneous Gait Abnormalities (ie Drop Foot, Polio, etc)
- Combinations of the Above
Since we are going to talk about lifts I thought I would give your spirit a lift first. I wish to express my gratitude to photographer/artist Robert Stallard for this breathe-taking view of San Francisco Golden Gate Bridge near sunset on one of our cold, foggy San Franciscan summer days.
The heel lift is the main method used in treatment of short legs and their problems. But, heel lifts are inherently unstable, and easy for patients to compensate for by simply bending the knee on that side. Once you bend the knee on the side you are trying to lift, you have lost the correction. Heel lifts, therefore, can make the foot/ankle more unstable by lifting up in the shoe more, and they can make the knee more unstable by producing greater knee bend/flexion.
Doctors are always placing the lift onto an orthotic device. This is not advisable. First of all, it makes it hard to decide what symptoms are related to the lift, and what symptoms are related to the orthotic device, when pain increases with orthotic devices. Secondly, because of the instability mentioned above, the heel lift may negate the added stability produced by the orthotic device. Golden Rule of Foot: Keep orthotic devices and lifts for short legs totally separate.
Full length lifts in the treatment of short leg syndrome are much more stable and produce better symptom relief. Full length lifts need to lift the heel and forefoot (metatarsal area) equally, then taper at the toes. This full length lift above, designed around a shoe insert template for W9 (women's size 9), is actually cut off at the toes to give room in the toe box area. Imagine all of the athletes who run up on the ball of their feet, but need a lift for their short leg, how could a heel lift do anything positive for their biomechanics and symptoms? At least 50% of the time most athletes are on the ball of the foot while exercising, so a full length lift seems ideal for the athletic population. Now athletes on the other hand would love the lift to be only under the heel for convenience and shoe fit, but it is so much better to have it full length.
If you use full length lifts, make sure you make cuts into the material by the ball of the foot to help with smooth push off. This is especially true as you get up over 1/4 inch in lift. Material under the ball of the foot can make it hard to move through, so cutting to increase bend, along with beveling and thinning slightly can all help.You can also see that the front edge of the full length lift is bevelled or skived to make a smoother transition forward. When I am using full length lifts, I always try to get feedback from the athletes on how easy it is to move through their foot. In podiatry talk, I am trying to avoid Sagittal Plane Blockade.
You can see the cuts do not go through the sides to help with its durability, but they do go completely through from top to bottom.
Not really demonstrated well, but these cuts do improve the bend of the foot making it easier to move gently through to the toes. There will be alot more discussions on lifts, short legs, gait dominance, and the biomechanics of injuries.