Friday, August 7, 2009

SMORGASBORG #3: Exoskeletons part B

Biomechatronic(1) feedback and motor systems could be used for prosthetic devices that replace limbs, or for exoskeletal structures that support and enhance function of an intact body.

External devices that interface intimately with human internal anatomy are represented in RoboCop, as Murphy's (Peter Weller) shattered corpse is resuscitated, amputated, and implanted into an exoskeleton that also serves as a prosthetic(2). The bullets from the men who murder him, and the surgeries of the people who "save" him, leave Murphy very little that can be physically recognized as the man he was. Once he is implanted within his carapace, and once additional devices are implanted within what's left of his body, he becomes even less recognizable as a man. Murphy is deliberately brainwashed in this cyborging process. He is rendered less than human by the people who re-make him. This movie is an engrossing investigation of our corporeal attachment to human identity(3). It's also a kick-ass action film.

Del Spooner (Will Smith) defending himself against an evil robot.

In I, Robot, Del Spooner has lost his arm as the result of a car accident. The arm has been replaced by a prosthetic. To Spooner's mind it is a robotic prosthetic, and Spooner hates robots. Although Isaac Asimov is light years away from this film, the amputee who hates his life-like robotic prosthetic (and himself, by extension) makes for good drama, I guess.

But in this film, Spooner remains a human and a man. Although he is conflicted about his acceptance of a prosthetic arm, he is unquestioningly human to all who know and see him. He retains his personality. He works out. He is a guy with a motorcyle. Unlike RoboCop, he is sexually attractive and has his 'nads(4).

Spooner's prosthetic upper extremity includes all of his shoulder and a number of ribs. This type of device probably has a surgically implanted interface, since there would have to be a design element that allowed the prosthetic rib replacement to maintain a vacuum between the lung and chest wall. I bet the prosthetic ribs even act and react to Del's rib movement and breath rate. This would require some kind of invasive interface with the nervous system. To support my logic, we see that the inside of the fake arm is all lit up and sparkly. It just screams fancy technology capable of anything. I rest my case.

Discussion of biomechatronics and the developments in prosthetics and exoskeletons brings us to what they could (and probably should) be used for, beyond killing and superhuman strength, I mean. What is that use? To restore normal function to a body that is missing a part, or that has been weakened, paralyzed, or otherwise damaged.

Some bodies are intact but unable to respond voluntarily to the will of the brain. This is the result of damage to the nervous system. Damage from injury or disease can happen in a number of different ways, and cause a variety of symptoms. Insult to a nerve may cause a complete flaccid paralysis(5) or a partial paralysis(6) to the part of the body the nerve served. Injury to the spinal cord can lead to paralysis or paresis of one or more limbs.

"Wrist drop" a.k.a. radial nerve palsy.
This painter suffered lead poisoning and lost the use of the muscles that extend the wrist.

Damage to the brain can lead to spasticity, rigidity, tremors(7) etc., anywhere in the body, depending on what part of the brain is damaged. A person with any of these conditions may have partial control over the limb, or no control at all. It depends on the extent of the damage to the nervous system.

A really funny comedian (with cerebral palsy).

What could damage, alter, traumatize, or injure the nervous system? Direct trauma(8), poisoning(9), or diseases(10) are the usual culprits.

Imagine, if you can, what it would be like to never stand up again. Imagine how your day would change if you could use your shoulder and elbow, but not use your hand, or what would it be like to walk with a foot that doesn't respond. Think about how your body would change if you could no longer contract muscles in your arms or legs. If a muscle stops contracting it shrinks (atrophies), just as it will grow in size if you exercise it. How would you feel about your physical appearance if your limbs were atrophied and much smaller than those of a more physically active person?(11)

This young man in New Delhi contracted polio myelitus.
Polio is caused by a virus that attacks motor nerves, leading to flaccid paralysis.

As a massage therapist, I have thought about these questions a lot. When you are touching a disabled body, and you develop a relationship with the body and the person, it forces you to think really hard. I have an intellectual understanding of the causes of many of these conditions, and the basics of various therapies one can undergo to recover from nerve and/or brain damage. I can appreciate the heroic efforts of my patients, even when they are at their pissy worst. But frankly, that knowledge doesn't help much. I know I've been lucky so far, and that my luck could change. I don't know how I would react to being struck by any disease or debilitating injury, until it happens.

As you would expect, my massage patients have all viewed their conditions differently. From observation, I have concluded that descriptive terms like "the worst thing imaginable," "pain in the ass," and "extremely frustrating," don't begin to describe the impact of losing physical function has on someone's life.

Yes, we are ending on a downer. Next time, exoskeleton technology applications for persons with paralysis.

1. See SMORGASBORG #2 for more on biomechatronics.
2. What is a prosthetic? An artificial substitute or replacement for a part of the body (eye, leg, breast, tooth) or a replacement for a joint (hip, knee). A prosthesis can be used for functional or cosmetic purposes, or both. You can go to for a more in depth definition.
3. Sorry for that last sentence, folks! I'm reading too much academic writing and it's causing me to "act out."
4. We assume Spooner's testicles and penis weren't harmed in the accident. With Murphy in RoboCop, the corporation orders the amputation of his viable leg. Through that act, it is implied that any other unneeded parts are also removed. He doesn't eat normal food. Digestion and excretion have been altered to fit his new being. Murphy wouldn't need a functional reproductive system, either.
5. Paralysis where there is a loss of tone, loss of reflexes, and atrophy (shrinkage) and degeneration of affected muscles.
6. Partial paralysis is called paresis. Partial flaccid paralysis may manifest as weakness in the body part.
7. Spasticity and rigidity are produced by excessive uncontrolled muscular contraction and are due to brain (as opposed to nerve or spinal cord) injury. Tremors can have a variety of causes, and like spasticity and rigidity, cannot be willed to stop.
8. Car accident, birth trauma, gunshot, stabbing, etc.
9. Lead, mercury, etc.
10. Multiple sclerosis, amyotrophic lateral sclerosis (ALS or Lou Gherig's disease), Parkinson's etc.
11. I teach lessons on massage for different deformities, and I'm used to using clinically descriptive language to describe these conditions. Terms like "valgus" or varus", etc. If I'm massaging a patient with a deformity, we're talking about their body, the state of the tissues, anatomical structures, goals for the session, etc. Or we're talking about movies, our pets, or food. I'm not current on the acceptable social language used to describe atrophy or other conditions. I'm not even sure that there are socially acceptable non-clinical adjectives out there. Any comments?


  1. I can see one reason for keeping Murphy's genitalia intact, and that's the hormonal one. If the corporation wants a good fighting machine, wouldn't testerone be even more helpful? Just a thought...

  2. Or, testosterone, to be more precise. ;)

  3. You know, I had the same thought so I'm glad you pointed that out. I considered writing about this, but thought it would be too off track. Now you've given me a chance to go with it.

    There is a generally held belief that higher testosterone levels will make one more aggressive and/or angry. Some sources dispute it, some say it is so only in high amounts. Whatever. An emotionally reactive machine might be harder for the corporation to control and therefore should be as machine-like as possible. They need a controllable, emotionless, killer. Plus Murphy no longer needs the extra muscle tissue his testosterone would supply. His exoskeleton is his physical strength. I figured the "leg" amputation was symbolic of removal of ANYTHING that was not necessary, or might impede control of RoboCop. On the other hand, Murphy's voice hasn't changed except to sound a little electronic.

    Personally, I like the idea (not literally!) that Murphy has be de-humanized as far as is possible. In his case, castration (there, I said it) takes the last vestige of manhood and sexual identity with it. From a Hollywood standpoint, what could be more dehumanizing than to lose your limbs, memories, AND sexual drive?

    Thanks for giving me a change to explain my "logic."

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