Stand with your hands by your sides, loosely closed into a fist with a pen in each hand. Now, bend your elbows so your hands are out in front of you. If you have kept your wrists unmoved, the thumb-end of the pens will be facing towards the ceiling. Or more precisely, if using a clock reference, your right pen will point to 11 o'clock, the left to 1 o'clock.
Now, imagine those pens are the grips on your mountain bike handlebars. Turn your hands until they approximate the position of your hands on your grips. Chances are your pens are now pointing at 8 o'clock (right) and 4 o'clock (left). You will note that to maintain this position your shoulder muscles are working extremely hard to hold your elbows so far apart, and how hard your wrist and forearm muscles are contracting to turn your palms towards the floor.
This natural position is a long way from where your hands actually grip
Back in the trailblazing days of mountain biking it was decided that cutting the ends off the wrap-around handlebars allowed for the ideal confirmation of weight distribution and control for piloting one's Schwinn down a scree slope. This led to the birth of the traditional flat handlebar, placing the cyclist's hands palm-down.
Seems John Tomac was on to something... back in 1990
Since then, aside from a short flirtation by John Tomac with drop handlebars in World Cup XC events, this bar design and therefore hand position has remained essentially unchanged.
For a period in the late '80s and early '90s, bar ends became fashionable, gaining traction because of their comfortable forearm position and increased leverage on the bars when climbing. Some adventurous manufacturers such as Scott incorporated the bar end into their handlebar design, but such variations have essentially ended up in landfill due to their awkwardness (increasing bar width and hooking on trees) and placing the rider's hands away from the controls.
What is abundantly clear, based on both personal experience and the type of discomfort and injuries we see at the clinic before and following MTB events, is that the hand and forearm position for mountain biking is extremely ergonomically unsound. The palm-down posture places the rider at risk of neck and shoulder pain, forearm muscle and tendon stress, and most significantly hand numbness with possible loss of strength (‘handlebar palsy’).
Easy solutions to try
We're pretty sure that bike design boffins have worked long and hard over improving MTB handlebar design to improve bike control and comfort, but it seems that either through concerns over a loss of bike control or possibly just down to convention, the status quo is here to stay. So to get the most out of a bad situation, here are some simple adjustments you can make to your current bars to reduce the risk of upper limb issues.
Bars in normal up-swept position, note the flaring of the elbows
Bars rolled backwards to be flatter across the top. Note how the elbows are in a more neutral position, thereby easing tension on your shoulders and neck
1. Roll the bars towards the rider, allowing for level grips. Note: the more rise and sweep the bar has, the more the bar is going to curve towards the rider. On some bars, this solution may not work (refer to suggestion 4 below).
2. Install foam or silicone grips, allowing a softer grip between the alloy or carbon bar and the sensitive structures of the hands. Note, common lock-on grips feature a solid plastic core beneath the rubber, and therefore do not offer as much cushioning.
3. Ride in the Specialized Grail glove. By consulting a hand surgeon, Specialized has recognised that traditional glove design padding the outside of the hand actually makes hand numbness worse. Instead, the Grail's padding is in the middle of the palm, dissipating load across the entire hand.
4. Install a bar with no rise, and minimal (zero- to six-degree) sweep. Excellent options are available from Pro, 3T and Thomson. This will demand a more aggressive position, with the grips being lower on the bike in relation to the stem, but the up side is that you will be able to grip the bars and feel your fingers (and screw open a beer bottle after your ride).
If all else fails, perhaps consider cyclocross?
The Body Mechanic series on BikeRadar covers topics from bike fit to injury prevention to how your component selections actually affect you. The Body Mechanic is a Sydney-based physiotherapy, bike fitting and cycle repair workshop established in 2008 by physiotherapist and former NSW elite state road cycling champion Blair Martin.