A key feature of many of the bikram yoga postures (poses) is the locking of the knee (lock the knee, lock the knee, lock the knee :-)). I like the direct forceful manner in which this instruction is confidently asserted by the instructors - there is a conviction in the instruction that they know that this is good for you. Whilst i have always stretched a lot, usually in a sporting context and have always gone for a straight leg, no information prior to my bikram yoga sessions has emphasised the importance of 'locked knee' and flexed foot where appropriate.
An excellent summary of what the locked knee does for you can be found here at http://hubpages.com/hub/bikram-yoga-lock-the-knee. An extract is included here:
"Rather than just straighten the leg in the standing poses, actively engage your quadriceps muscles
and you will never have sore knees, your walk will feel lighter, you will be preventing any future issues - and as a side-benefit, your hamstrings will gain more flexibility and lengthen more easily, which is a boon for many of us with tight hamstrings from sitting at desks all day or from sporting activities!" (hub pages, Roger One - retrieved 11 April 2009)
An article that seems to talk contradictory to this view, but comes across as an authoritative piece is Yoga And Preventing Knee Locks - at http://www.myyogaonline.com/yoga_article_120_Yoga_and_Preventing_Knee_Locks.html
"The ‘knee lock’ presents some useful function and purpose in allowing one to stand without using the quadriceps to hold the legs in a straight position. This creates an energy-efficient mechanism that allows you to maintain the knee in extension over prolonged periods of standing without requiring muscular contraction." (My Yoga Online - retrieved 11 April 2009)
I tend to take the former view that actively engaging your muscles is the right way to go and am wondering whether i have not quite understood the second view as i find it difficult to believe that there could be such a contradiction. Another quote from My Yoga Online that i have mixed views on is:
"The purpose of Yoga poses is to generate physical vitality so one can proceed through life with positive energy flow and with a holistic connection to what brings balance and harmony. Standing Yoga poses offer these benefits when mindfulness and proper intention is applied. Without mindfulness, some standing Yoga poses present a tendency towards knee locks and hyperextension, which can produce chronic problems in the function and health of the knee joint." (My Yoga Online - retrieved 11 April 2009)
I like the idea of mindfulness in that the 'locked knee' is executed with mindfulness and that the knee is not hyperextended. on the other hand this comment still gives the impression that 'locked knee' can lead to injury, which may be the case with hyperextension, but i do not believe this wouLd be the case with a correctly performed 'locked knee'.
Linked into the concept of 'locked knee' is the flexing of the toes. on this point I'd like to say that many of the relevant yoga postures can be performed without flexing and 'locking of the knee', which is an attractive proposition for beginners because it is the easy option. in my opinion new yogis :-) need to build themselves up mentally and physically by working towards a 'locked knee' position and flexing where relevant. The value of flexing is reinforced for me by the comments of Andy Baran in his book 'Gymnastic abs' - where his advice to students is "its; not just the exercises. it's how you do them" and his specific general advice (if that is not a contradictionj in terms :-) is
"Flex everyone of your muscles, not just your abs. I said before but it bears repeating. When you flex all your muscles you are creating connection between all your muscles. The ability to focus on every muscle of your body while you flex them will create that connection and make you incredibly strong." (Andy Baran 2007, Gymnastic Abs, p.7)
For those of you interested there are quite a number of Bikram Yoga centers in London and three outside Leicester, Manchester and Brighton. As i understand it there are centers at various locations throught USA and Europe, but do not have exact details. To now more about Bikram yoga here are a some links:
and finally the issue of maintaining good hydration is covered well in this article: