Variable Incline Plane

Years ago, I discovered a product called a Total Gym which is one type of a Variable Incline Plane (VIP) (others are listed below).

I use a VIP when a client can’t stand up from a chair or climb a flight of stairs, for example, because the movement hurts or they don’t have enough leg strength.

The VIP helps “tailor” the load to the individual to find just the right amount of force, to find the best “fit”.

By adjusting the angle of the device up or down, you can increase or decrease the force into the legs as you perform a squatting motion.

The ability to make small adjustments in load makes it possible to identify an amount that does not create symptoms and/or permits a well-controlled movement pattern.

For example, let’s assume you weigh 160 lbs. and rising from a chair hurts your right knee. This means that 80 lbs. of force is too much for your right knee (80 lbs of your 160 lbs on each leg).

Depending on the make and model of the VIP, the highest or most upright position will be about 60% of your body weight. At 160 lbs., the load would be 160 x.60 or 96 lbs. for both legs.

If you were to perform a squat with this load, your right knee would likely not hurt. In fact, with a little testing, you could find a pain-free level of load.

The VIP has become a central component of much of our work with clients because it provides more control over the loads and subsequently the volume of exercise.

A weak knee joint (or any weight bearing joint) needs both controlled load and motion to improve. The VIP provides both.

The cost of a VIP can range from $200-300 to $2500 or more depending on the make and model. We have not tried all of the products in the list below but we have suggestions on what to look for in a VIP.

For info on choosing a VIP, here’s my colleague Laurie Kertz, explaining how to evaluate a VIP.

TOTAL GYM – For better control over the foot-to-knee position, get the larger footplate here and here.
VIGORFIT
WEIDER BODYWORKS
TOTAL TRAINER – you might be able to find one of these on eBay or Amazon. The company recently discontinued the model I recommend.

For personal guidance in how to use a VIP to strengthen the knee or other weight-bearing joint and a free, 20 minute Strategy Session, please contact my colleague Laurie Kertz by clicking or tapping here.

Load Tolerance Testing Using a Variable Incline Plane

Conducting a Load Tolerance Test is one of the most useful features of a Variable Incline Plane.

To understand how to use a VIP, however, you need to first understand a few key concepts.

KEY CONCEPTS

Load Tolerance is the amount of pain-free force you can produce or absorb for a specific movement, over a specified period of time and still control the movement.

For example, let’s assume your right knee hurts to stand up from a chair.

If you repeat this movement but place a little more weight on the left leg, you might discover that your right knee no longer hurts.

This suggests that the right knee has a specific “load tolerance” – at some level of reduced load, less than equal distribution on both legs, you’re able to perform the movement without pain and control the movement. But we don’t know what the actual value is and it’s therefore more difficult to use the information in exercise program design and to track improvements.

Pain-free force is the amount of physical load your body can withstand without pain being detected and while maintaining proper form. This might seem straightforward and simple to apply but oftentimes, because many people have lived with chronic pain, their expectation of pain-free isn’t actually pain-free.

I’ve had clients who have replied, after being asked if the test was pain-free, saying, “Not really” or “It’s not that bad” or “I can manage”. All of those statements mean that the test was not pain-free.

Pain is binary. You either hurt or you don’t hurt. The feeling of pain is a gradation from minor to severe.

For a Load Tolerance test to be valid and useful, the test must be pain-free except in one situation.

For people who have had pain a long time, sometimes the Load Tolerance test procedure has to be modified. For example, you might be able to find a load level that decreases your feeling of pain and a level that makes it worse. This will be a range of load. On the lower end, the pain decreases but doesn’t go completely away and on the upper end, there’s a load level that increases pain. While this is less than an ideal result, We have used this kind of result successfully. Usually, on subsequent tests as the body improves, so does the Load Tolerance test.

Training Environment describes the amount of gravitational force that is used during an exercise session.

There are four Training Environments: sub-gravity, gravity, gravity plus and super-gravity.

Sub-gravity is a training environment that includes forces that are below bodyweight loads. Gravity means bodyweight loads, gravity-plus means bodyweight plus a light additional weight and super-gravity includes bodyweight plus additional weight plus speed.

Movement from person to person varies such that defining one type of movement as “normal” is inaccurate. A Movement Pattern is the result of coordinating movement at different joints either simultaneously or sequentially or both.

There are movement patterns that are ideal and movement patterns that are not but some people can move with a pattern of movement that might be defined as less than ideal and have no symptoms and function just fine. While others might hurt a lot yet have ideal movement patterns.

Movement patterns become more of a concern when the Load Tolerance test loads are in the gravity and gravity-plus forces. When the loads that are tolerated are sub-gravity, the movement pattern is much less of a concern.

How To Perform a Load Tolerance Test Using a Variable Incline Plane

Let’s go back to the earlier example of right knee pain that hurts during standing up from a chair.

A VIP can help us find the numerical value of your right leg load tolerance since the force that’s being used during the test is a percentage of your body weight.

The procedure:

Generally it is safe to start at a level on the VIP that corresponds with a load of 25% body weight (each VIP wil have a different number of levels with each level corresponding to a percentage of bodyweight which is obtained from the manufacturer).
Perform five squats using both legs through a range of 0 – 90 degrees of knee bend using both legs to acquaint yourself with the movement and machine.
Perform five squats through a range of 0 – 90 degrees of knee bend on the non-painful leg. Note how this feels – smooth, easy, not painful.
Perform five squats through a range of 0 – 90 degrees of knee bend on the painful, in this case right, leg.
If this series of repetitions is non-painful, raise the machine up one level, wait 2 minutes and repeat the test on the painful side.
Testing continues until you notice pain, the movement feels different than the test results of the other leg or until form begins to break down due to weakness.
Squat load tolerance is recorded in pounds (or as a percentage of body weight) as the highest level where you can perform five unilateral squats without pain or form breakdown.
View video by clicking here

The most common mistake people make is not noticing the onset of pain but waiting until they notice significant pain. The test stops when you notice any pain and sometimes that will reveal itself as just feeling different from the other leg.