Surgeons who want to impress upon their trainees the psychosocial importance of hands might cite the harrowing experience of New Zealander Clint Hallam. In 1998, an international team of surgeons grafted the right hand of a deceased Frenchman onto Hallam’s forearm, some years after he’d lost his own in a circular-saw accident. Enabled by a number of late-twentieth-century medical innovations, the complex procedure yielded impressive results. Within a year, Hallam had gained enough motor and sensory function in the donor hand to perform many activities of daily living with it, and his case was widely lauded as the world’s first successful hand transplant.
In 2001, one of the surgeons agreed to amputate the donor hand, citing irreversible physical rejection as justification. However, interviews with Hallam suggested that this was not his only reason for pursuing the procedure. The donor hand was noticeably bigger, lighter-skinned, and less hairy than his surviving hand, and bore scars, grafts, and excess flesh from the transplant procedure. The mismatch made him uncomfortable, and shocked others so much that he often hid the donor hand with clothing and gloves. After two years of struggling with his altered body image, an onerous immunosuppressant drug regimen, and numerous bouts of physical rejection, he’d become disgusted with and “mentally detached” from the donor hand and could no longer bear to be physically attached to it.
If aesthetics and social acceptance strike you as trivial concerns in Hallam’s circumstances, consider all that we rely on hands for beyond physical agency. Superficially, they’re an always-on channel for broadcasting affiliation, status, and values, as women Olympians do with their patriotic nail art; British aristocrats with family coat-of-arms rings; American high school grads with class rings; Hindu brides with henna tattoos; and Catholic nuns who wear wedding bands after betrothing themselves to God. The more I consider such symbols, the more of them I notice, and it’s interesting to consider why we want other people to know what we tell them with hand decoration.
Hands bear the marks of our professions, hobbies, and habits. A coder keeps her fingernails short to facilitate typing. A classical guitarist keeps their right fingernails long for plucking and strumming. A builder may develop calloused palms from laboring with tools, and a massage therapist may maintain soft ones by working scented oils into clients’ skin. Nicotine-stained fingertips suggest a heavy smoker; ragged nailbeds suggest a nervous nibbler; and pinpricked thumbs an avid needleworker.
Hands in motion signal our feelings with terrific economy, as with the internationally recognized thumbs-up for “good,” or the Italian cornuto (index and pinky raised, palm out) for “fuck off!” They extend greetings and blessings, such as the Muslim adaab (slight bow with fingertips raised to one’s forehead, palm inward), the Filipino pagmamano (forehead bent to an elder’s outstretched hand), or Spock’s Vulcan salute on Star Trek (palm out, double-fingered V with outstretched thumb). They refer with a finger-point, mimic to express desires (check, please!), play clapping games and make shadow puppets, create works of art and, by writing and typing, transmit information and ideas among people and over time.
Hands also amplify the spoken word, as poet Amanda Gorman’s did so exquisitely with her recitation at the 2020 US presidential inauguration and they can obviate the need for it entirely, while conveying meaning in ways that speech alone cannot. People conversing in American Sign Language, for instance, can express multiple ideas simultaneously, and entire sentences with a single gesture. And classical Indian dancers tell ancient legends through a standard repertoire of gestures called mudras—which, according to a medieval Sanskrit text, crucially enhances the narrative: “For wherever the hand moves, there the glances follow; where the glances go, the mind follows; where the mind goes, the mood follows; where the mood goes, there is the flavor.”
Symbolically, hands infuse spoken language with flavor, too. I’ve been equally irritated and amused by the frequency with which I’ve had to strike grasp, on the one/other hand, and similar imagery from this manuscript, not wanting to distract you with unintended puns. I couldn’t possibly deny myself all of it, though. It’s too useful, too plentiful. Why? One contemporary philosopher suggests that humankind’s hand-intense interaction with the physical world naturally inclines us to consider it in manual terms (though not exclusively). For instance, I use the same coffee mug every day not just because it holds a lot of coffee, but also because its handle is easy to hold with my impaired right hand. It’s hardly a leap from there to apply manual terms to our conceptual world. We grasp objects, and ideas are the objects of our mind. Why not grasp ideas, too?
And then there is touch. Delicate, exposed, and sensitive, our hands ask for care and offer it with touch, like a teammate’s congratulatory backslap, a friend’s consoling hug, or a lover’s arousing caress. When it is welcome, interpersonal touch is pleasing in itself. It enhances well-being in many more ways besides, strengthening social bonds; promoting trust, cooperation, and generosity; and acting on the nervous system to alleviate stress, feelings of social exclusion, and physical pain. And we suffer when deprived of it.
While we intuitively understand hands’ multidimensional influence on our lives, it is also supported by a robust body of research. Studies exploring people’s experience of hand loss or serious impairment, for instance, commonly cite the far-reaching economic, social, and emotional challenges such events can precipitate. Among them, occupational changes necessitated by disability within a work environment designed for typical hands; social stigma in a culture where the word typical has come to mean “correct”; and injury to a sense of self bound up with hands’ appearance and the independence they enable. Anxiety or mood disorders may also result.
Thus, in continual service both physically and psychosocially, hands become an integral part of who we are, with the power to influence self-regard and others. Considering this, one can appreciate why Clint Hallam struggled to accept a donor hand that served him so poorly across dimensions. His is not everyone’s experience, though; many people adapt and thrive in changed bodies, and in chapter 14, I’ll touch on the role of OT in that process.
Still, surgeons encountering a severely injured hand today will do everything they can to preserve both function and form. In doing so, they’ll pay particular attention to peripheral nerves, knowing the devastating impact of lost motor and sensory function, and that even sensory impairment alone can cause difficulties. If you are typically handed and want to better appreciate these facts, consider turning your bedtime routine into an experiment tonight. Using just one hand (and no cheeky assists from cohabitants), strip off your street clothes, return them to their drawers and closets, and don your pajamas.
If you’re really keen, next put on a pair of gloves and complete the rest of your routine, two-handed—makeup and contact lens removal, face-washing, toothbrushing, whatever your usual drill. Throughout, notice what’s harder to do and what’s not, what adaptations you make to compensate for your temporary impairment, what goes wrong, and how long everything takes relative to your usual pace. Afterward, were you more aware of all that your hands, and particularly their sensations, enable you to do?
My awakening to that effect began in the ambulance on the night of my accident, when I had the ghastly impression of sensibility itself draining out of my right hand. At first, the hand had felt like it always did when inactive and unstimulated: unfeeling, yet having a feel to it that told me it was there and part of me, even when I wasn’t looking at it. But over the course of the ride, that sense of “thereness,” or embodiment, receded steadily from fingertips, to knuckles, to the heel of my hand, and into my wrist, where the median nerve serving it had been transected. It was as if my hand had disappeared somewhere between Brooklyn and Bellevue, except that it remained in plain sight. Out of sight, my body was preparing for peripheral nerve regeneration.
As a refresher, a nerve is a bundle of axons. An axon is the stemlike part of a neuron, and individual axons are ensheathed in Schwann cells, plus an outer layer of connective tissue. The axons in peripheral nerves stretch from neuron cell bodies in, or near, the spinal cord to specific sites in the skin, muscles, or organs. There, the axons’ branched endings communicate with target cells, either to transmit central nervous system commands to muscles, or to relay data about the body’s environment to the central nervous system to inform those commands.
Upon transection of my median nerve, part of this feedback loop was broken, causing loss of motor and sensory function in much of my hand. The regeneration program would attempt to restore it by extending the live axon segments—those above the wound, thus still connected to their cell bodies—across the wound to their original targets in my hand. (Because this program operates on the level of the axon, not the entire nerve, I’ll refer to it as peripheral axon regeneration from here on out.)
To clear the path for regenerating axons, the dead axon segments (those stretching from the wound into the hand, thus cut off from their cell bodies) disintegrate in spectacular, instantaneous bursts, leaving their Schwann cell and connective tissue sheaths behind. Taking charge of the scene like the Red Cross in a natural disaster, these Schwann cells recruit immune cells to help consume debris from the disintegrated axons and other tissues damaged in the accident, and to kill pathogens that may have entered the body through the wound. They also flood the area with proteins that will instruct participating cells in their roles in regeneration.
Meanwhile, the cell bodies shift from transmission to growth mode, churning out protein building blocks for their axon extensions. These will give the extensions a stringy, stretchy form and, at their tips, a growth cone, which one neuroscientist I interviewed vividly described as a “grippy hand” for the way it propels a regenerating axon forward, adhering to, then pushing off of, cells along its path.
Within days of transection, cleanup is usually complete, and axon regeneration begins. The live axon segments sprout their growth cones, which reach across the wound to begin the journey toward their targets in the hand, via the connective tissue sheaths abandoned by the disintegrated axon segments. Concurrently, Schwann cells in the axon sheaths reorganize themselves to provide the growth cones with nutrients and a “sticky” surface they can easily grasp along the way. To help keep them on track, the Schwann cells also secrete proteins as beacons, and the growth cones continually repoint themselves toward the areas of highest protein concentration. If enough axons reach their targets in the hand and reestablish communication with the central nervous system, some motor and sensory function may be restored.
Any step of the process can go wrong, however, and regularly does. The live axons might fail to cross the wound site, despite surgeons’ providing them a bridge—via nerve sheath repair (as in my case, when the gap to be crossed is relatively small) or nerve graft (when the gap is large). They might be blocked by scar tissue or lingering cellular debris. Growth cones can veer off course, despite the Schwann cell protein beacons. If an axon’s progress is too slow, Schwann cells may not be able to nourish and guide it for the duration of its journey, or its target cell may die for lack of innervation before the axon arrives. Finally, the body’s immune response to injury could fail, allowing infection to take hold; or the immune response could persist too long, thus inflicting dangerous amounts of “bystander damage” (killing off healthy cells as well as pathogens).
It seems a miracle, then, that peripheral axon regeneration ever proceeds as “designed,” and given this, I wondered about my future hand the same way parents-to-be might wonder about their future child: Will it be healthy and capable? What will it look like? Will it feel part of me? How will it change me, and my life?
It would be months before I had even an inkling of the answers, since peripheral axons grow an average of about a millimeter per day under the best of conditions, and mine had up to twenty-four centimeters to cover. In the meantime, I could do nothing to promote healthy regeneration beyond eating and sleeping well and taking my prescribed antibiotics. This was nature’s stretch of the three-legged race to restore my hand function, and she would dictate the pace and quality of performance. Though accepting that fact felt acutely unnatural.