(01-07-2013 01:38 AM)cgkeogh Wrote: [ -> ]I notice the elastic index formula on page 41 of software manual is CMJ-SJ/SJ * 100, i always understood the elastic index formula was CMJ-SJ/CMJ *100?

Can someone elaborate?

thanks

Ciaran

Hello Ciaran

Sorry for my late answer

I tought the formula came from Bosco, Luhtanen & Komi 1983, "A Simple Method for Measurement of Mechanical Power in Jumping", but it doesn't.

In Bosco & Komi 1979, "Mechanical Characteristics and Fiber Composition of Human Leg Extensor Muscles" they talk about the observed differences between CMJ and SJ but they do not offer comparative calculations

In Bosco 1994, spanish book: "La valoración de la fuerza con el test de bosco" he writes on "elastic index" as a comparison between CMJ and SJ, (pag 97). I understand CMJ-SJ. This is related to elastic capacity by other authors.

In Bosco 2000, spanish book: "La fuerza muscular", I found in page 252: "When we compare CMJ/SJ ...", and in page 258 I found: "If we compare the relationship (CMJ/SJ) ...". Then he seem to use this CMJ/SJ instead of the elasticity index.

In Josep Ma Padullés PhD Thesis, page 354, I found the "(CMJ-SJ) /SJ" formula and a reference to Bosco 1986 but sadly this is not referenced on the bibliography by mistake.

If you search in Google: "elasticity index" CMJ SJ Bosco, you found some pages like: topendsports that uses the "(CMJ-SJ) /CMJ" formula:

http://www.topendsports.com/testing/bosco-ergo-jump.htm
or this article:

http://www.free4act.com/1/upload/relazio...rs_eng.pdf
that uses this formula

Muscle elasticity = ((CMJ-SJ)/CMJ)100

others like these articles use the "(CMJ-SJ)/SJ":

http://cdeporte.rediris.es/revista/inpre...ad457e.pdf
If you search in Google Scholar "CMJ - SJ / CMJ", you find 13 results.

http://scholar.google.es/scholar?q=%22CM..._sdt=0%2C5
There are some articles that use this formula, and others like this that uses "IE", elasticty index, but they don't tell the used formula:

http://www.revistakronos.com/docs/File/k..._15_12.pdf
If you search in Google Scholar

"CMJ - SJ / SJ", you find 18 results:

http://scholar.google.es/scholar?q=%22CM..._sdt=0%2C5
and you can see clearly the formula on some of them

Some other articles:

http://cdeporte.rediris.es/revista/revis...alto68.htm
uses "/SJ" formula

In my humble opinion, is better to use the "/SJ" because it refers to an improvement. You expect that CMJ is greater and for this reason is better to show it putting SJ in the denominator.

I published a link to this question in spanish forum (it's lot more active than english forum) and I hope that someone will help us:

http://foro.chronojump.org/showthread.php?tid=1287
Cheers