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Actually I use different fins, depending on the demands of the dive, Jet Fins are a resonable all around compromise, sort of second best at most everything.Dear Thalassamania, what a diving bio you have and still using jet fins. You must have had fun working with Captain Billy Deans. I made the Excellator fin for him.
I was not working with Billy for fun, we were WORKING. You know ... combining our efforts to enhance both of our paychecks.
In all honesty, I have nothing either for or against your fin, I tried them and they were not to my taste, but I'm the first to admit (see below) that there's a learning curve to any fin and I only used them on one dive. I was left with the feeling you have when biking up hill in too low a gear and having to spin faster than you want to.
When a study has N=1 then it is anecdotal regardless of how "scientific" it appears. That is to say, "based on casual observations or indications rather than rigorous or scientific analysis," which requires a sufficiently large sample size to pull the signal out of the noise.I fail to see how measured "data" can be "anecdotal" , the terms are by definition in opposition.
the conclusions drawn in the paper have a particularly small data set (1 diver) so the stastical validity may be drawn into question, but the scientific method and collected evidence is quantified data, not anecdotal. The conclusions drawn from the data follow the evidence collected to date and matches up with the current understanding of exercise theory.
So until you put up the money to expand the data set and prove the data wrong, or gain a PhD in Sports Medicine and Physiology to interpert the existing data differently you are in no position to discredit the data or the interpretation of it.
I think it is a very promissing approach and I hope to see it pursed as a way to compare a number of different fins.One reason I thought Ryan's study was so interesting
Form my original post-
Ryan used a biomechanical analysis software program called Peak5® to digitize video footage of a swimmer moving past a viewing window in a pool kicking conventional fins and when kicking Force Fins. The software translated the range of motion, acceleration and velocity the hip, knee and ankle joints into data points that show the differences in that range of motion to reveal the strain put on those joints of the leg when kicking the fins.
Ryan was getting real information on the different effects of using different fin designs in the water, a comparison with no room for human interpretation. With the Peak5® software he could translate video footage of a diver’s leg in motion into percentages of range of motions on joints of the body, interpret forces acting on legs using known bio-mechanic norms and limitations of the human leg.
Many, many years ago we tested five different fins (sorry, the Force Fin was not in test group). We used ten subjects and a highly robust experimental design that controlled for many variables, including training effect, that is to say our dependent variable was oxygen cumsumption, measured by weighing the oxygen bottle from an oxygen rebreather before and after each test, over a defined course. The independent variables included fin model, subject's number, subject's initial fin preference, time to swim a mile, number of previous trials, number of previous trials with a give fin, etc. Subjects were divided into two groups, on succeeding days one group of five swam five different fins in rotation until they had five trials on each fin, the other group of five swam one fin design five times (each trial on a succeeding day) and then switched to the next, and so on. The data was normalized and run though an ANOVA. As I recall the most significant item was the block effect due to trial number in the group that swam one design fin five times in a row and then changed design. The conclusion was that within normal boundaries (we intentionally used one fin design that we all agreed was the worst possible ... the Fara-Fin with the ankle brace). Guess what? There was a more significant reduction in oxygen consumption in the second group's fifth trail with a given fin than there was between the fin types with the exception of the the Fara-Fin, which was the worst in every possible way. I love to see a similar experiment replicated with Peak5®.
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