Suzanee W ~ For the exercises I did on the Box, you can do them kneeling directly on the carriage. For the first series, it will test your balance more, but it still will work in the same way. For the Quadruped exercise, you may need to change how you are moving the leg in the strap, depending on how high your Reformer is. You can try a bend and stretch motion instead of a sweeping motion for the first variation of the sequence. Hopefully, this makes sense! Let me know if you have any questions!