Biking after a knee injury: Wexelpunkt brings adapters for crank shortening

Andreas Sextl is a physiotherapist and former triathlete. He knows from countless conversations with patients that cyclists want to get back on their bikes as quickly as possible after a knee injury. That's a good thing, because even weight-bearing and continuous movement when pedalling is an integral part of any knee rehabilitation programme. Especially after an operation, the mobility of the knee joint can often be significantly restricted. There is a lack of flexion and extension. For many patients, cycling only seems possible with expensive special equipment in the early recovery phase. But not when it comes to Sextl!

Cycling despite limited knee mobility

Those affected are familiar with the problem: after an injury to the knee joint the way back on the bike is often a rocky one. At a certain point, therapists place the injured person on an ergometer with a shortened crank. The first step back to biking normality and yet, in the enclosed space of a rehabilitation centre, it feels infinitely far away from the sport they love. For some dedicated bikers, the usually brief moment on a stationary bike is not enough. You want a solution to do something for your knee on a normal bike too. Others get it worse and the mobility of the joint takes years to reach acceptable levels.

I still remember the first time I sat on an ergometer with shortened cranks after a serious knee injury. I pedalled very slowly, carefully and unsteadily. It was the most wonderful feeling in the whole time after the accident and gave me new hope to get back on the bike. Apart from the physical rehabilitation benefits, a crank shortening adapter can give injured people a positive mental boost. - Jan Timmermann, BIKE editor

Crank shorteners not only help patients to use their bike despite a lack of knee mobility, they also take the strain off the knees and hips. Specialised cranks with a one-sided shortening are not only difficult to find, but also often expensive. Andreas Sextl from Wexelpunkt didn't want to accept this and started developing an adapter in 2021 that could turn any bike into a rehab device. With his experience as a physiotherapist and athlete as well as feedback from his cycling patients, Sextl now wants to make the crank adapter ready for series production. His solution has been legally protected internationally since July 2023. The first Wexelpunkt adapters are due to be delivered from spring 2024. Pre-orders can be placed via anfrage@wxvario.de possible. Cost per unit: 169 euros. The conversion kit for use on the right or left costs 59 euros. More information at: www.wexelpunkt-wxvario.de

Crank shortening for every bike

The crank adapter from Wexelpunkt is designed to fit every crank and every bike with a standard pedal thread - regardless of whether it's an ergometer, road bike, city bike or MTB. This is made possible by adjustable clamping jaws with 3D-printed parts and a finely adjustable aluminium rail. A threaded unit holds the pedal, while a highly stable screw engages in the thread of the crank. Assembly is extremely simple. The high manufacturing quality of all parts was particularly important to Sextl. The crank adapter is approved for body weights up to 110kg and also for light mountain bike use.

I have seen the need for a universal and affordable crank adapter for years. The existing solutions were all unsatisfactory, so I developed an adapter myself. - Andreas Sextl, Physiotherapist Wexelpunkt