Back Action Clasp

• A single-arm clasp providing single bracing only
• The minor connector originates from the major connector at the ML line angle remote from the denture base
• The bracing arm extends above the survey line on the palatal surface till the proximal surface then starts to taper to engage the MB undercut (0.01 in)
• Stress-breaker => used in free-end cases
• Poor bracing and reciprocation => contraindicated in unilateral RPD

Reverse Back Action Clasp

• The minor connector originates buccally from the saddle at the MB line angle.
• The bracing arm engages the ML undercut (0.01 - 0.02 in)
• Indicated on Lingually tilted bicuspids