|（Athletic Training Department，Guangzhou Sport University，Guangzhou 510500，China)
Abstract: In order to further verify the magnitudes of patellofemoral joint compression forces (PFJCF) produced at the supporting stage of forward or backward running at the same speed, the author selected 8 healthy testees to par-ticipate in the test of forward and backward running at the same speed, collected kinematic and dynamic data of the running process, adopted inverse dynamic and PFJCF related calculation methods, and revealed the following find-ings: the difference between the ratio of PFJCF to body weight measured during forward running and the ratio of PFJCF to body weight measured during backward running was not significant, but the ratio of PFJCF to body weight measured during forward running was slightly greater than the ratio of PFJCF to body weight measured dur-ing backward running. ((3.57±0.43) BW; (3.14±0.92) BW; P>0.01). The author concluded that at the same running speed, backward running can be used as an exercise means to alleviate PFJCF, probably because backward running can appropriately reduce PFJCF, since PFJCF is mainly determined by the magnitude of knee joint muscle torque, and the magnitude of ground reaction force.
Key words: sports biomechanics；patellofemoral joint compression force；backward running；forward running