Plank Times Not Related To Injury In Collegiate Track And Cross Country Athletes

Abstract

While trunk muscle endurance is important in running kinematics, the evidence on static trunk endurance tests like planks and their relationship with lower extremity injury risk in athletes is conflicting. PURPOSE: To determine whether prone and side plank hold times were associated with time-loss injury in track and cross country athletes. We hypothesized that shorter plank times would be associated with a higher incidence of lower quadrant injury during the season. METHODS: Seventy-five NCAA Division III collegiate track and cross country athletes (39 females, 36 males; mean age 20.0 ± 1.3 y) performed three trunk endurance tests in random order with 1-2 minutes recovery. Hold times for prone plank (PP), right side plank (RSP) and left side plank (LSP) were each recorded in seconds (up to 120 seconds) during the first week of the competitive season. Athletes were followed prospectively during their season for any lower quadrant injury resulting in limited or missed practices or competitions. Independent t-tests were used to compare mean plank times between injured and non-injured athletes. Odds ratios were used to assess the risk of injury for athletes with a plank time below the hold time cut points. RESULTS: The mean plank times between females and males were similar (p > 0.05). Twenty-seven athletes (36%) experienced a time-loss injury. The mean plank times between injured and non-injured athletes were not significantly different: [PP: injured 88.3 ± 33.3, non-injured 92.1 ± 31.1 (p = 0.63); RSP: injured 73.6 ± 32.7, non-injured 76.4 ± 31.9 (p = 0.72); LSP: injured 72.0 ± 30.8, non-injured 76.2 ± 32.4 (p = 0.59)]. Overall, 17.3%, 24.0% and 26.7% of athletes had hold times <60 seconds for the PP, RSP and LSP, respectively. When comparing athletes with hold times of <60 and ≥ 60 seconds by injury status, no significant associations were found for PP (p = 0.40), RSP (p = 0.16) or LSP (p = 0.66). When the sums of PP, RSP and LSP times were assessed, no significant risk relationships were found between injury for athletes in the lower half (p = 0.53) or lowest quartile (p = 0.39) of hold times. CONCLUSIONS: Pre-season plank hold times were not related to injury status during the competitive season. Static trunk endurance assessment tests in isolation may not be sensitive for injury screening as they may not match the dynamic demands of these sports.