If a client has trouble sitting upright with legs straight which muscles are likely tightest? Hip flexors? Hamstring? ADVERTISEMENT 6.00K viewsSeptember 28, 2012 0 Jo0 September 28, 2012 0 Comments I have a client with well developed core strength but sitting in that 90 degree position is a struggle. I’m not too flexible myself in that position and I know I have very tight piriformis and IT band but what else might be involved? 10 Answers ActiveVotedNewestOldest 0 Joanne0 Posted 0 Comments What is the client sitting on? Can he/she sit upright when sitting on different surfaces (i.e. a seat as opposed to the floor). You are viewing 1 out of 10 answers, click here to view all answers. Register or Login