Middle palmar space ends distally

C i.e. Web space Fascial Spaces of The Palm These are potential spaces filled with loose connective tissue and their boundaries limit the spread of infection in the palm. The triangular palmar aponeurosis fans out from the lower border of the flexor retinaculum. From its medial & lateral borders a fibrous septum passes backward and is attached to the anterior border of 5th and 3rd metacarpal bones respectively.