deepakrajan
Hi Deepak,
One option for you might be to purchase the lion (or the horse) which would give you a good insight into choices made for attachments etc. Ziva also sells human anatomy complete with Ziva attachments, tissues, etc.
Here's some ideas concerning attachments: I tend toward conservatism when using attachments. By that I mean few vertices per attachment, and with the exception of origin and insertion attachments, weaker stiffness values. This will prevent your system from being over constrained, and looking stiff.
Origin and insertion attachments (muscle to bone) I ususaly have fairly high, something like 1 x 109.
Muscle-muscle sliding/fixed attachments are weak in comparison, something like 1x104 or 1x105
Lastly, only try to attach things in close proximity to each other. Unless you really have to, you want to avoid using long attachments, especially sliding.