Why do you need to worry about ergonomics at all? You've been riding that motorcycle for 10,000 miles, and aside from the occasional numb hand, it's fine. Every rider gets numb hands, right? Perfectly normal, right? Wrong. Numb hands, especially when associated with wrist ache, can be a symptom of repetitive stress injury (RSI). RSI is more common amongst motorcyclists than one would imagine. Living here in Silicon Valley, we tend to think that 80-hour-work-week computer programmers are the only ones at risk for this ailment, but the fact is that motorcyclists are also highly susceptible, due to the repetitive motion of turning the throttle and squeezing in the levers. The two most common examples of RSI are tendonitis (also called "tennis elbow") and Carpal Tunnel Syndrome (CTS). Both are extremely painful, slow to heal, and will keep you off of your bike for weeks at a time.

It's worth taking a moment to explain what tendonitis and CTS actually are, and what can cause them. Tendonitis is the swelling of any tendon; motorcyclists usually experience this in their forearms or bicep areas. Repetitive motion causes tiny tears in the tendons, which become irritated and swollen if they aren't given time to heal. CTS is particular to the wrist area; the carpal tunnel is actually an area of the wrist, made up by the carpal bones on the sides and bottom, and the carpal ligament on the top of the wrist. Passing through this tunnel are the main nerve to the hand (the median nerve), along with the nine tendons which attach muscle to bone and allow your fingers and thumb to bend. This area is extremely susceptible to tendonitis, but due to the small area involved, when the tendons here swell, they can put pressure on the median nerve and cause it to press against the carpal ligament. This pressure reduces blood flow to the nerve, which is what causes the numb hands and fingers. Think of it this way -- picture a flexible tube with a string inside it. If the tube is straight, it's easy to pull the string back and forth through it, right? However, if you bend the tube and try to pull the string through it, the string will rub up against the bend in the tube, causing friction. In this example, the tube is the carpal tunnel in your wrist, and the string is the tendons and nerve in your wrist. If your wrist is bent, the tendons will rub up against the carpal ligament and median nerve, causing irritation to all.

If you experience any sort of hand, arm, or wrist ache when riding, it's time to examine your riding posture. Sit on your bike and put your arms on the grips in your normal riding position, hands resting on the levers. Look down at your arms; you should be able to draw a straight line from your forearm down through your wrist to your knuckles. If you're at a bad angle to see your arms, ask a friend to look from the side for you. You want your wrists to be straight while you're squeezing the levers; your tendons need a smooth ride through your carpal tunnel. If your wrists are bent at all, especially if you ride a bike which causes you to put weight on your wrists (most sportsbikes do), you might be setting yourself up for CTS. Fortunately, there is an easy and free way to reduce this risk -- simply unscrew the mounts for your levers, and pivot them down until your wrists are less bent. At first, you might feel as though you're "grabbing down" on the levers, but you'll quickly get used to it.

If you have clip-on handlebars, you can also adjust the angle of the bars to make sure that equal pressure is applied across your hand. If you notice that one side of your hand is pressing on your bars more than the other side, loosen up the bolts that hold on the clip-ons, and angle them closer or further away from you, until the pressure across your palm is even.

Another easy thing to check is the adjustment of the lever itself. Most modern hydraulic levers (and even some cable ones) are adjustable, which makes them extremely easy to customize. If your hands are small or you're experiencing wrist pain, adjust your levers closer to the bar, so that you aren't using your fingertips to do all the work. If your clutch is stiff, but you have a cable clutch, fear not -- adjusting the cable can give you more free play in the lever. This will bring the friction zone of the clutch in closer to the bar, so that you're using the "meat" of your fingers, and not just your fingertips, to pull the clutch in.

If you've already adjusted all that you can adjust, and are still having problems, it's time to look into aftermarket products. Handlebar risers, such as those sold by HeliBars and GenMar, can raise your handlebars and bring the grips closer to the seat. This will give you a more upright seating position, in which you're less likely to be putting weight on your wrists. If these manufacturers don't make risers for your particular motorcycle, there are always alternatives. Most sportsbikes, for example, have 41mm diameter front forks, and a clip-on from one bike might be taller or at a better angle than your stock clip-on. I recently replaced the stock clip-ons from my 2001 Suzuki SV650S with a pair of clip-ons from a 1989 Honda Hawk GT, with excellent results. An internet search or an inquiry on a message board dedicated to your particular bike might dig up some similar alternatives.

Unfortunately, sometimes we don't act in time, and the damage is done. If you notice wrist pain at all -- whether it's a sharp twinge or a constant dull ache -- mention it to your doctor. Your general practitioner can do some general tests for RSI, and refer you to an orthopedic doctor if necessary. RSI doesn't go away on its own, especially if you're continuing to ride, so it's worth talking to someone about. The best self-treatment that you can do in the meantime is, unfortunately, not to ride. Tendons need time to heal, and it's better to take a couple of weeks off of the bike than to do permanent damage to yourself. If you use your hands for non-riding activities, such as computer work, there are many flexible braces that you can buy which will help to keep your wrists straight. Handeze makes a nice, extremely flexible, hand covering which will help mild pain. I use a Futuro sports brace while typing at work during the day, since it's a bit more rigid than the Handeze. If the pain persists, a rigid wrist brace with metal inserts in it will keep your wrist immobile. I noticed that buying one of these braces to sleep in nightly made a large improvement in my RSI. Ibuprofen will also help to reduce swelling, but be careful not to take so much that you end up masking the symptom (pain). Also, stay away from aspirin, which isn't an anti-inflammatory, and can also thin your blood -- bad news if you're riding and have an accident.

Motorcycle ergonomics is truly one of those areas in which an ounce of prevention is worth a pound of cure. Even if you haven't noticed any problems in your posture, check your levers and make sure that they're adjusted correctly for you. This simple 10-minute check might save you from weeks of pain later on down the road. Also, while you're on the road, don't forget to stop and stretch every time you stop for gas, or about once an hour. Have fun, and ride safe!