Experts say about two million U.S. workers are exposed to hand-arm vibration on the job and as many as half of them will develop Hand-Arm Vibration Syndrome (HAVS). Otherwise known as White Finger, HAVS is a permanent and irreversible medical condition in which fingers, hands and arms lose feeling and/or have continual tremors based on the after-effects of frequent and prolonged operation of vibrating tools or machinery. Extreme cases have resulted in the loss of parts of or entire digits. Here’s a look at what causes HAVS, how to recognize symptoms and how to mitigate the damage.

Anybody who’s ever spent a few hours weeding, pushing a lawnmower or going for a lengthy bike ride has probably experienced it on some level: tingling and numbness in the hands and arms.

It's not your imagination. Hand-arm vibration is a real thing. And Hand-Arm Vibration Syndrome is a genuine affliction that particularly affects workers who regularly operate vibrating machinery as part of their daily work routine. While HAVS can disproportionately have an effect on workers operating heavy machinery, such as jackhammers, even less jarring tools such as hand saws, power drills and, yes lawnmowers, can still contribute to more modest incidents of HAVS.

HAVS is nothing that should be taken lightly. While occasional use of vibrating machinery may only cause numbness and tingling for a few minutes or hours, regular, sustained use of such machinery can lead to severe cases of HAVS that can be both debilitating and irreversible.

In cases such as sustained jackhammer operation, for example, an individual may suffer a loss of grip strength and decreased dexterity, an increased chance of developing arthritis, tendonitis, carpal tunnel syndrome, and even experience chronic pain.

Difficult to predict

Some of the higher HAVS risk occupations, not surprisingly, include construction, sheet metal work, welding, automotive repair and electrical work. If a job requires the regular use of any machinery that vibrates at all, the potential exists of developing HAVS to some extent or another.

Because of its slow-to-show, long-term progression, often times HAVS isn’t diagnosed until the damage is done. It’s notoriously difficult to predict from individual to individual. Some people are just more susceptible or attuned to vibrations, and are therefore more apt to suffer HAVS symptoms. Others can work an entire lifetime in high vibration environments and never experience any problems whatsoever.

The exact underlying mechanism responsible for HAVS is generally believed to be a disruption in the flow of oxygenated blood through the body's vascular system. This is particularly pronounced at the extremities most associated with HAVS symptoms. Sustained exposure to vibrations can eventually damage the tissues themselves, at which point the condition may become irreversible.

As stated, some of the early onset HAVS symptoms include tingling and numbness, which may or may not dissipate after a relatively short amount of time. With sustained vibration exposure, however, tingling and numbness can give way to more ominous symptoms. Visual manifestations can include a noticeable change in skin color, or whitening, of the extremities, which usually occurs in combination with a heightened sensitivity to hot and cold temperatures. In fact, HAVS is more likely to afflict individuals who work outdoors in extreme temperatures.

HAVS is preventable 

In more advanced cases of HAVS, patients may experience a loss of function to affected areas. Even mundane tasks like filling a glass of water can become incredibly difficult. In its most advanced stages, HAVS can lead to visible tissue damage, and even gangrene.

Fortunately, HAVS is preventable. Following these five tips is a good start:

  1. Use anti- or low-vibration tools.
  2. Hold them as loosely as possible and in multiple positions.
  3. Ensure those tools are well-maintained and inspected regularly.
  4. Take regular 10-minute breaks. Short bursts of work with a vibrating tool are less harmful than long period of continual vibration.
  5. Keep yourself (especially your hands) warm at work. Cold exhaust air from pneumatic tools should be kept away from hands.

Other administrative controls include rotating workers to do the task, so no individual worker has prolonged or repeated exposure to the vibration hazard.

As a last line of defense, employers should provide anti-vibration PPE for their workers as well. Specialized products like vibration-reducing work gloves that meet the requirements of the ANSI S2.73/ISO 10819 standard and feature a gel or other padded palm that reduces vibration, and dampens shock and impact, which can further reduce the negative effects of vibration on workers.

Employing the above tips combined with regular worker rotation and use of anti-vibration PPE will ensure you’re doing your part to prevent HAVS on your jobsite.

More Information:

HAVS Educational Page

Anti-vibration Blog Post