In the Pennsylvania workers’ compensation system, we frequently see cases involving carpal tunnel syndrome (CTS). As many of you know, this condition occurs when the median nerve is entrapped in the wrist. There are many potential causes of CTS, including familial history, certain medical conditions, trauma and certain physical activities. CTS can also occur “idiopathically” (without a known cause). Frequently, we see litigation regarding whether CTS in any given case is related to the work activities.
Are we all at the same risk to develop CTS? According to a recent study published in the Archives of Physical Medicine and Rehabilitation, and referenced in The Wall Street Journal recently, the size and shape of a person’s hand and wrist can show whether that person is predisposed to the development of CTS. Specifically, if a person has a “short and wide hand with square wrist matching to narrow and deep tunnel entrance,” that person has an increased likelihood for developing CTS. Of course, that leads us into an examination of what causes CTS, and whether CTS in any given case can be accepted as a work-related injury.
According to the University of Maryland Medical Center, “Work that involves high force or vibration is particularly hazardous (to developing CTS), as is repetitive hand and wrist work in cold temperatures.” They also note that repetitive use of the hands and wrists can cause repetitive stress disorder, overuse syndrome and chronic upper limb pain syndrome. Similarly, the National Health Service in the United Kingdom relates that CTS can be triggered by activities with “strenuous grip, repetitive wrist flexion and exposure to vibration,” including motions associated with manual labor. This is consistent with the view of the National Safety Council, who noted that “(r)epetitive manual work tasks requiring a forceful grip and use of vibrating tools can damage the median nerve in the arm, contributing to CTS.”
As you are reading this, also understand that for an injury to be compensable under the Pennsylvania Workers’ Compensation Act, the work duties do NOT need to have CAUSED the CTS. It is sufficient if the work duties “aggravated” the underlying condition, rendering the injured worker disabled. Whether the injured worker may have eventually developed CTS, even without the work activities, is irrelevant. Similarly, whether the injured worker had the size and shape of his or her hand and wrist to be predisposed to CTS has no meaning. We simply take what we actually know – the injured worker performed his or her work duties and developed CTS as a result.