DESPERATE: Tomb Raider Anniversary for Wii question!?

I've been playing Tomb Raider: Anniversary on the Wii for the past few weeks, but now I'm stuck. I'm in the Obelisk of Kahmoon level in Egypt, in the tall room where Laura has to reach ledges by doing wall runs past spinning blades before they come out again and cut her grapple cord. I've tried over a dozen times, and I just cannot get past the part with the second blade/wall run where Laura has to do a wall run and then jump to the handhold above the one she initially wall ran from. Every time I try, Laura can never reach the second handhold/ledge and either ends up back on the first one or falling to her death after I try to gain more height by swinging back and forth an additional time (the blades come out and cut her cord, causing her to fall). So please, if anyone has any tips as to how I can get past this, I would immensely appreciate it! Thanks :)