The seventh race at Parx on Monday was declared a no contest after a one-horse spill left jockey Mychel Sanchez lying unconscious in the center of the turf course on the first turn of the 1 1/16-mile race. The outriders waved the remaining eight runners in the field to a halt in the stretch. Sanchez was aboard Shake Things Up for trainer Jorge Navarro in the $16,000 claiming race. Shake Things Up was racing in third position entering the first turn when he appeared to break down, although it is possible he may have clipped the heels of Vinceremos. Shake Things Up was euthanized due to his injuries. Sanchez regained consciousness, was placed on a stretcher, and transported to Aria Health-Torresdale in Philadelphia. On Tuesday morning, his agent Josiah Hampshire Jr. said Sanchez had not broken any bones in the spill but had a concussion. Sanchez could resume riding as soon as this weekend. Sanchez, a 21-year-old native of Venezuela, has won 308 races since he began riding in 2013. He is second in the Parx rider standings this year with 71 wins. Win, place, show, exacta, trifecta, and superfecta wagers on the race were refunded and the race was treated as an all-winners leg in pick threes and pick fours. The $31,000 purse of the race was split evenly between the eight horses who were waved down in the stretch and their eight riders were awarded a $350 jockey's mount.