dear Pawel Posluszny

this sites may be help you

http://ajcn.nutrition.org/content/72/3/796.full

http://www.topendsports.com/testing/muscle-mass.htm

http://healthyliving.azcentral.com/measure-muscle-bone-mass-11378.html

http://www.livestrong.com/article/498130-the-formula-to-calculate-fat-mass-lean-muscle-mass/

http://www.builtlean.com/2011/08/24/lean-body-mass-definition-formula/

http://www.ncbi.nlm.nih.gov/pubmed/15115164

http://www.topendsports.com/testing/tests/muscle-mass-calculation.htm

http://www.nerdfitness.com/blog/2012/07/02/body-fat-percentage/

http://www.bodybuilding.com/fun/lbm_calculator.htm

http://fitness.stackexchange.com/questions/5151/how-to-accurately-measure-muscle-mass-versus-body-fat

I think the answer to this question depends on your population. If these are healthy adults, of healthy weight I think the common equations may provide you with an estimate (I am unclear if any of the above referenced formulas have been validated). However if your population falls outside of this scope of "normal healthy adult" then these equations will not be helpful. The act of actually measuring this whether it be by bioelectrical impedance (with phase angle), ultrasound, biopsy or a combination of these will provide you with the most accurate results.

Dear Mr. Pawell,

Like our colleague brilliantly answered, the equation will always be dependent of the population you are analyzing. Anyhow, Mr. Al-Gindan, has recently published a systematic review about this topic (first link) in which I believe you will find a lot of interesting information and articles (in the bibliography), and as the paper emphasizes, Mr. Lee's equation look's very promising, in Brazilian journals it has been already validated (versus DXA) in elderly men (.pdf). I also am sharing another paper with very important considerations about anthropometry (second link), although not a new one, it's from Vivian Heyward, I think that is all one must say.

Best regards,

-Edgard Soares

http://www.scielo.br/pdf/rbcdh/v14n1/en_a03v14n1.pdf

Article ASEP methods recommendation: Body composition assessment

Article Predicting muscle mass from anthropometry using magnetic res...

Dear Pawel Posluszny.

Several of our colleagues have suggested interesting solutions to solve your problem. Therefore, any additional information would be repeating what has already been said so I send you two references, one for appendicular mass calculation of old and the other for general use.

Martin, A.D.; Spenst, L.F.; Drinkwater, D.T.; Clary, J.P. Anthropometic estimation of muscle mass. Med Sci Sports Exerc. 1990; 22:729-33.

Piettra Moura Pereira Galvão, Danny Alcantara da Silva, Gilberto Moreira Santos, Luiz andAmandio Petroski Edition Aristides Rihan Gallagher. Development and validation of anthropometric equations to estimate appendicular muscle mass in elderly women. Nutrition Journal. 2013; http: www.nutritionj.comcontentpdf1475-2891-12-92.pdf

Additionally, I suggest reading the chapter: Estimation of Muscle Mass.In: Human Body Composition. Roche, A.F.; Heynsfield, S.B.; Lohman, T.G.

Good luck

 Amandio Geraldes