A tensioning device comprises an elongate member, preferably a band, and a frame having first and second sides. The band has a first end that is attachable to the first side of the frame and a second end that is releasably securable to the second side of the frame. A movable clamping member on the frame secures the second end of the band to the second side of the frame by cinching the second end of the band between an engagement surface on the band and a mating engagement surface on the second side of the frame. A restraining member is provided for restraining the clamping member to a first position spaced from the mating locking surface on the second side of the frame, when the restraining member is in a restraining orientation. The restraining member is movable out of the restraining orientation after the band is tensioned to a predetermined level using the second end. The band is tensioned to the aforementioned predetermined level and is secured to the second side of the frame, so that the band establishes a path of tension along its length that extends linearly between the two ends of the band.