 |
 |
In a message dated 12/14/98 9:11:58 PM, [log in to unmask] writes: >As far as I can tell knee extension is still a movement and although it >does isolate the quads I think it can be useful for strengthening. In >a JOSPT article this year it was discussed that examination of gait >reveals there is open and closed chain activity and therefore isolated >closed chain activity is not the only way of doing things any more. >Now, who knows what percent open versus closed chain activity should be >done? ***What concerns me more about the issue is the isolationist or uni-articular approach involved in most 'open chain' exercises, rather than their open- chained nature per se. Physios spend a lot of time learning the merits of PNF and its associated multi-articular patterns of movement, then they are thrust into world of isokinetic and isolationist machines which tend to overshadow the importance of functional patterns of movement with a central stress more on nervous processes than muscle action. After all, we constantly hear the dictum:"the body knows only of movements, not muscles", yet far too many therapists, scientists and coaches still seem to examine or treat the musculoskeletal system as if it were just a separate peripheral system with no central command centre. That JOSPT article concerned referred to closed and open chain movement in the context of functional movement and that is a very different situation compared with the so-called non-functional open chain methods which are involved in isokinetic testing or training. There are also profound central, peripheral and biomechanical differences between uni-articular exercise (e.g. machine leg extensions) and multi-articular open chain exercise (e.g. the swing phase in walking or running). There needs to be a more logical combination of non-functional and functional uni-articular and multi-articular exercises for rehab and training instead of the bias towards the simpler, more easily quantifiable methods of isolation exercises on isokinetic and related machines. Some of those vastly overused isolationist 'rotator cuff' exercises with light weights also tend to ignore some perfectly good PNF patterns which address the same problem quite competently and tend to dominate over more functional multi-articular procedures. Whenever I have used the terms 'open' and 'closed', I have done so with certain reservations, since this classification scheme is not at all as clear or accurate as often believed (I raised this issue in a much earlier Puzzle & Paradox and considerable discussion of this appears in the archives of this group). Dr Mel C Siff Littleton, CO, USA [log in to unmask] %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%