Anti-Tip Tubes on Your Tennis Court Chair

One of the biggest fears for any wheelchair user is to fall over backwards. Yet in order to demand the performance of a sport wheelchair, the center of gravity must be pushed to the limit. In the past, there existed a point of diminishing return since the chair would at some point turn over. Alas, not to worry…enter the sports anti-tip tube.

An anti-tip tube is a small wheel (one or two) at the end of tubing that extends behind the tennis chair that keeps the chair from turning over. Actually, the older style wheelchairs had anti-tip tubes, which carried out the safety function but did not have the performance component. This relatively new addition to the sports chair world has improved the quality of play for most players.

The sports style anti-tip tube allows its user to displace weight further back than normal. This lightens the front end and increases the chair's lateral response time. In addition, during a start, an athlete can press back against the anti-tip tube for quicker ‘out of the hole’ mobility and improved performance. The higher your lesion or functional ability, the more important an anti-tip tube becomes.

When shopping for an anti-tip tube on a tennis chair, make sure that the anti-tip tube extends far enough behind the rear wheels to provide proper support. Athletes vary in how high they set the caster off the ground, but they all agree on setting the height high enough to avoid high centering.

Let’s break it down a little more. I see many chairs with anti-tip tubes and I feel they are not being used properly by players. It is necessary to dissect mobility to understand it better:

Phase 1 or static mobility
Phase 2 or moderate mobility
Phase 3 or active mobility

Static mobility is represented during serves or overheads. Moderate mobility is used during ground strokes or to re-direct the court chair. Active mobility is extreme movement during an all out push like an emergency ground stroke or drop shot retrieval.

The two problems I see are:

1. most competitors haven’t adjusted their chairs enough to get their mass ‘behind’ the axle position and
2. once the player goes there, he or she does not understand how to use the tipper to enhance active mobility. They limit their impetus to avoid "spinning out" at the end of the turn.

To solve the first problem, adjust your chair so the weight displacement is now behind the center of gravity. Secondly, you must SPEND TIME THERE during training sessions to increase the comfort level.

As far as the second problem, try using 1-inch wide upholstery for more thoracic/lumbar support and straps (artificial muscle) to stabilize the ‘dead’ parts of the body. Once the turn is initiated during active mobility and the spin begins, pull the body slightly forward to negate centrifugal force that wants to send you out of the turn. The more you practice this technique, the more proficient you will become.

Also, you don’t need as much camber when properly using the anti-tip tube. This will reduce your resistance down the court and help align the wheels ergonomically with your arms. Many adjustments to the chair are recommended to arrive at an optimum sitting position.