What was found
2 SEAT BACK SUPPORT STRAPS BROKE ON HARD LANDING (G-METER REUD 9G) UPPER STRAP WAS A NEW BREAK AT WELD CENTER STRAP BROKE AT REPAIR WELD FROM PREVIOUS BREAK. CFI IN REAR SEAT SUSTAINED MINOR BACK INJURY, AIRCRAFT LT MAIN GEAR COLLAPSED RESULTING IN PROP STRIKE. 3-G NEGATIVE READ ON G METER IS BELIEVED TO OCCURRED WHEN AIRCRAFT SLID ON NOSE FOR 100+ FT ON ASPHALT RUNWAY. ALUMINUM SHEET FOR BACK SUPPORT MIGHT ALLOW BETTER LOAD DISTRIBUTION IN LIEU OF STEEL STRAPS.