To Be Exact, Behind Handlebars & Aerobars
As with all your contact points on the bike, it’s important that your bike fit is optimised to enable a great position without the cost of comfort. If comfort is not there, efficiency is affected and so, therefore, is speed.
I am sure most of us who ride a bike have experienced that feeling of pins and needles in the hands, often along the ring and little finger. You take your hand off the bars, make a fist, wave your hand around and the sensation reduces and disappears. Hands back on the bars, back up to speed, and a while later it is time to repeat the process. On each occasion, whilst you do this, you reduce your speed (not to mention that one-handed cycling causes changes in ride posture/pressure on other contact points).
Clinically, this is known as Handlebar or Cyclist’s Palsy. It is commonly associated with compression of the ulnar nerve. The median and ulnar nerves provide sensory innervation to the hand. Compression most frequently is in an anatomical space in the wrist called the Guyon’s Canal. Depending on your choice(s) of hand position on the bars and the setup of the front end of your bike, numbness may also be experienced around the thumb, index, or middle finger. This will be compression of the median nerve and may be diagnosed as Carpal Tunnel syndrome. This is more common among mountain bikers and the cross -triathlon community due to the different handlebar configuration and hand position.
For triathletes, from novice to experienced, there then comes the question of aerobars. Incorrectly set up aerobars increase the risk of ulnar nerve impingement at the Cubital Tunnel at the elbow. As the ulnar nerve travels from the neck to the hand, compression of the nerve may show symptoms along this path. Most often symptoms are numbness and tingling in the hand or finger of the affected side and difficulty in the application of finer motor skills i.e. changing gear in an aero position.
Handlebar Palsy can be split into four categories, with a fifth category to consider in relation to aerobars, according to where the compression occurs. Each has its own characteristics of sensory loss and/or motor weakness. While it is unusual for age group triathletes and cyclists to suffer motor impairments, any symptoms and their causes should be managed to avoid the risk of long-term chronic damage.
Research in this area over a number of studies indicates that this is an important issue for a growing number of athletes riding on aerobars. Cross-referenced studies have shown increases between pre-event and post-event symptoms and end-of-season symptoms have shown a further increase. Triathletes and Time Trialists should research or take advice on the best shape of aerobar design and configuration for their individual biomechanics.