Posted on 04/24/2009 5:47:07 AM PDT by Liberty1970
At Stanford University, California, two sales representatives from Nike were watching the athletics team practise. Part of their job was to gather feedback from the company's sponsored runners about which shoes they preferred.
Unfortunately, it was proving difficult that day as the runners all seemed to prefer... nothing.
'Didn't we send you enough shoes?' they asked head coach Vin Lananna. They had, he was just refusing to use them. 'I can't prove this,' the well-respected coach told them.
'But I believe that when my runners train barefoot they run faster and suffer fewer injuries.'
Nike sponsored the Stanford team as they were the best of the very best. Needless to say, the reps were a little disturbed to hear that Lananna felt the best shoes they had to offer them were not as good as no shoes at all.
When I was told this anecdote it came as no surprise. I'd spent years struggling with a variety of running-related injuries, each time trading up to more expensive shoes, which seemed to make no difference. I'd lost count of the amount of money I'd handed over at shops and sports-injury clinics - eventually ending with advice from my doctor to give it up and 'buy a bike'. And I wasn't on my own. Every year, anywhere from 65 to 80 per cent of all runners suffer an injury. No matter who you are, no matter how much you run, your odds of getting hurt are the same. It doesn't matter if you're male or female, fast or slow, pudgy or taut as a racehorse, your feet are still in the danger zone.
But why? How come Roger Bannister could charge out of his Oxford lab every day, pound around a hard
(Excerpt) Read more at dailymail.co.uk ...
I wear them until they're worn out, but always get good quality. For one thing, the Walmart brands have more plastic in them and start smelling. They also feel more rigid. I'm usually either in running shoes, Hi Tech Magnums or firefighting boots.
We didn't get to put our boots on for probably two weeks.
I shoulda asked one of 'em for the reasoning behind this after we graduated...
That reminds me of a long forgotten memory...I went to a private school for my 8th grade, and they had a pretty decent track team, most of whom were high schoolers.
There was a history teacher (thinking back, probably late thirties - which appeared old back then), with a beefy build and a blend of barrel chest and paunch.
Every one in awhile, he'd go down to the track in his full suit and issue the 100 yard dash challenge....he never lost, and those runners were seriously wanting to beat him.
You look at the end case, not the usefulness of intermediate stages in themselves.
Evolutionists often falsely claim that creationists do not make predictions, so let me make one here: the sensory function of the plantaris will turn out to be vindicated in the end.
And if it is, it will be done by scientists, not creationists. But it's not looking too good, especially with a decent percentage of the population already being born without them. Maybe we'll figure it out about the time they disappear in our species.
For a similar twist on running shoes see the following link:
http://www.popularmechanics.com/outdoors/sports/4314401.html
Since I grew up running before the Jogging Revolution and Nike came along, I experienced the transition from slipper-like track shoes to modern trainers, in fact I still have a pair of old Adidas Tokyo spikes hidden in my closet (don't tell Jean!). It truly was more like running barefoot.
In my role as a WSU exercise and sport biomechanics teacher, I once got into a public debate at a convention with a shoe company researcher in the early '70's. I contended that by beefing up shoes the way they were beginning to do it back then, that they were taking large numbers of unfit people in this, the beginning of the jogging revolution, and sending them out onto the roads to be injured. My contention was that people needed to learn to run as children did in my era with the freedom of barefoot running before sending them out on the hard surfaced roads
I used a similar approach to teaching children gymnastics. Before introducing them to mats for tumbling, my students learned to roll on hard surfaces over different body parts to learn how to protect themselves by finding the naturally padded areas of the body and how to accomplish break falls utilizing muscles and joints as shock absorbers. Isn't take long for a child to discover what body parts hurt when they do it "wrong"!
Shoes do a great job of protecting peoples feet from the injuries of urban, rough surface running (like paved surfaces), but the wide-heeled models can even lever the foot into an ankle sprain or twisted knee situation on an uneven surface (such as a pothole or hitting a rock) when a more minimalist shoe or barefoot runner will likely just experience an "ouch."
It will be interesting to see if the barefoot running movement takes off and whether the entrepreneurs capture a new market with the barefoot like "shoes" such as the Vibram with its built in toes (they really look weird!).
Now, if one of you would just discover a way to grow and implant new cartilage in my knee so I could again run barefoot I'd be happy!!!
Well that is certainly an interesting looking shoe. Those MBT’s they are talking about is the same as the Sketchers I bought in Vegas.
*************
Wow, you do get into some esoteric discussions, don't you! I haven't thought about the plantaris muscle since mom tore her Achilles tendon before you were born. If you've never heard the story, she was playing in the finals of the Detroit Public Parks tennis tourney when she went down when her tendon snapped. It was on 4th of July weekend and only residents were available in the emergency room at Providence Hospital when we arrived. The young kid diagnosed it as a torn plantaris and sent us home claiming it was an expendable muscle and wouldn't cause any long term problems. We got home and she had to walk upstairs to our apartment, and of course couldn't do it very effectively. I put my finger where her Achilles tendon was supposed to be and new we had a problem. We got back in the following Monday to see an orthopedic surgeon and he sent her in the next day for surgery. Of course she was in a cast for a lengthy period thereafter - and that's when you came into the picture!! You were born the following summer.
Ok, back to plantaris. First of all it's not even a given. Not everyone even has one, and it's small size doesn't allow it to accomplish much mechanically - which seems to be part of what you were discussing with someone (maybe when we next talk you can fill me in about your interest in this whole discussion). If you looked it up in an anatomy reference you might even have trouble finding much written about it. In fact many of my texts skip right over it.
The name, which includes "plantar" refers to its possible mechanical role in plantar flexion, i.e., depressing the foot as in flexing the ankle joint when you jump or push down on an accelerator peddle. It's considered an extrinsic muscle in that the belly of the muscle is distant from the structure it supposedly moves, assuming that plantar flexion of the foot is what its purpose is - which may be where your discussion is headed. Can it play a role at the knee joint since it's a biarticular muscle, crossing both the knee and ankle joints. Biarticular muscles logically can influence both of the joints crossed but are usually leveraged to affect one more than the other in normal function. A good example would be the gastrocnemius muscle which is also biarticular and is situated very close to plantaris, but with much greater force capability because of its much larger cross section of contractile tissue. It shares a distal attachment on the calcaneous (heel bone) and thus mechanically has the same leverage characteristics as plantaris - but again, the gastroc is much more powerful!
So, what are their roles at the knee joint? First of all, you have to recognize that when a muscle shortens and applies its tension force it applies the same force to BOTH its proximal and distal attachments. Has to, according to the laws of physics (think Newton's 3rd law of action and reaction). Which attachment provides the greater movement depends on the inertial resistance at the respective attachments. This subject was actually the focus of my doctoral dissertation where I studied what are considered "reversible joint actions". When the hands are fixed to a chinning bar the elbow flexor torque produces movement of the body up to the bar, but if you strap someone's feet to the floor and pull on a bar cabled to an equivalent to body weight load in a weight stack (something like a so-called lat machine in weight training facilities, for example), the elbow flexors (such as biceps brachii and brachialis) produce the same muscular activity (recorded on an electromyogram) even though the so called "origin" and "insertion" attachments are reversed. That's why I abhor those terms as used in anatomy texts and always had my students use the more descriptive anatomical terms of "proximal" and "distal" attachments which bear no prejudice about the impending movement caused.
Muscles simply contract and apply their same tension force to both their attachments and the resulting movement depends on the resistance to that tension force at each respective attachment. Theoretically one attachment may move a lot while the other moves little (such as when an unresisting hand moves toward your mouth when you feed yourself - which anatomically would be considered a regular or normal movement), or, as described above, you can have a reversal of the normal joint actions for a given torque about a joint (such as in the chin up example).
Actually, most of the locomotor functions (such as walking, running, etc.) are reversals of movement from what is normally described in anatomy texts as movements from the anatomic position - which is how students studying musculoskeletal function usually are taught.
Back to the knee joint. When one stands relaxed, the knee joint is mostly extended but is normally just slightly flexed. That is, you don't force the knee into a hyperextended, locked position. To maintain normal relaxed standing posture there has to be a fine interplay between the inertial loads on the joints, range of tightening in joint capsule and ligaments, shapes of opposing bone structures, and closely controlled fine bursts of muscle activity under the feedback circuits of the neural sensors embedded in the joints and muscles - so called proprioception.
A simple experiment demonstrates how reflexes are involved in normal standing posture. I used to call an unsuspecting student to the front of the room and have them turn around and face the class. Then while talking to them and assuring them to relax while I lined up directly behind them, I would suddenly take both of my knees and simultaneously bump the back of their knee cubit area so that a sharp, quick stretch was applied to the upper gastrocnemius region just below the knee joint. Invariably the unsuspecting student would experience (and demonstrate to the class) two classic reflex responses: first the sharp, quick stretch induced relaxation in the postural control muscles posterior to the knee joint and the person starts to collapse and flex the knee joint; immediately following is a slower, stretch reflex induced in the quadricep muscles that posturally maintain the knee joint in an extended position. The person "catches" himself and the quads fire to again extend the knee joint.
This little experiment demonstrates that the gastrocnemius, and perhaps the attendant plantaris, are involved in a feedback loop with slight controlling postural muscle activity of knee flexion torque - even though in normal standing the knee joint is in a primary position of extension. In other words, when this knee flexion torque is interrupted, the knee joint begins to collapse under gravitational influence in flexion until the resulting stretch reflex is activated in the knee joint extensors of the quadriceps femorus.
This so called stretch or myotatic reflex is similar to what you experience when a doctor tests your patellar tendon reflex when he taps the patellar tendon just below your knee and your leg involuntarily extends in a kicking motion. The patellar tendon is the distal attachment of the quadriceps femorus group of muscles.
I doubt many studies of plantaris have been conducted because of its apparent lack of importance. I did see one mention that in comparative anatomy studies, the plantaris is often quite a bit larger and more important in plantar flexion of some animals as its distal tendon attaches below the foot with more leverage, rather than on the calcaneous as in the human. Perhaps this type comparison is what you are looking at if some evolutionist is arguing some comparison between animals and humans.
I'll look forward to talking to you about it tomorrow.
I don’t think barefoot running would get me very far. I’ve got an extremely high instep, and feet that are shaped like that are stiff. A normal foot flexes a little bit to absorb shock, and foot with a high instep simply isn’t capable of doing that. I have to have a running shoe that is designed to cushion, to make up for what my own feet can’t do. I know when it is time to change out to a new pair of shoes, because when the cushioning is shot, I get “runner’s knee,” and it progressively gets worse ... until I change to a new pair of shoes, then the “runner’s knee” goes away without having to take any break from my running schedule.
Funny about hitting the back of the knee. That’s what they do to you in the Army when they have you standing at parade rest for long periods to catch those people who have their knees locked (and will in due course fall out because of it).
But as you see with the plantaris, the best we seem to have is an “it might be good for...” and that’s about it. Nobody has ever shown that those who are born without it, or who have it removed, are in any way hampered by its absence. Having a larger one doesn’t seem to have a benefit either.
There's something about the evolutionary model that doesn't make sense to me. First it suggests that natural selection drove a relocation of the plantaris muscle from one position to another (assuming other primates represent our ancestral plantaris orientation). But then, conversely, that function was lost entirely. If it is functional in the ape orientation for ape locomotion, and not functional in humans in erect locomotion, then why would natural selection first push a change and then abandon it?
I haven't seen anyone suggest what it could have been useful for in the past in the current orientation. Yet both creationists and evolutionists would agree that there must have been some function for it in the current orientation at some point!
My father would also be interested in evolutionary insights, as noted below:
******************
In comparative anatomy between humans and animals there are all sorts of muscles that have the same name but because God designed the animals to function differently (four footed animals compared to us upright humans, for example)the muscle(s) might have different leverage characteristics and therefore quite different functions.
I remember noting many such comparisons in my cat comparative anatomy class as an undergrad at Eastern Ill. We used human models and texts but of course had no human cadavers to dissect so cats were used so we could gain a better understanding of how muscles operated and how the various joints functioned.
Both humans and cats might have a trapezoid shaped back muscle named "trapezius" that looks very similar but because of normal orientation to gravity would likely play far different roles.
What's in a name? Similar differences in lengths of tendons, how the tendons are routed around boney "pulleys", and differences in types and points of attachment could all influence function. I choose to believe these differences exist by design, not by some process of evolution. ...
I've done very little reading on the opposing viewpoints regarding such anatomical anomalies but would like to consider it further. As you come across such material, perhaps you can share it with me.
yet, they weren't a necessity before the 1970's... what has changed?
Because the evolution of the animal ended up with that muscle not being needed. Evolution is not perfect, with a lot of dead-ends and half-assed results. It is a process.
So if the current plantaris lacks a function in this orientation, according to evolutionary theory there still had to be a function for it in this orientation in the past. Otherwise it would never have migrated in the first place.
Depending on the beach: sticks, rocks, shells, jellyfish, and dog plotz.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.