Validity, Sensitivity, And Reliability Of Remotely Administered Push-up And Plank Tests

PURPOSE: To measure validity, sensitivity, and reliability of push-up and plank tests when administered remotely through videoconferencing. METHODS: We administered an in-person strength measure and two remote field-based tests of muscular fitness in adult clinical exercise trial participants (n = 150; mean age 61.6 ± 12.8 years; 77 (51.3%) female; 77 (51.3%) cancer survivors). Tests were administered at baseline and after a 6-month strength training program. To assess reliability of remotely-administered tests they were repeated one week after baseline measures by the same (intra) or different (inter) assessors. Maximal strength was assessed in-person by 1-repetition maximum bench press (1RMBP). Tests of muscle fitness included a push-up (standard or modified knee) and plank test. Pearson’s correlation coefficients were used to determine validity of the push-up and plank tests to 1RMBP. Paired, one-sided t-tests evaluated the sensitivity of the 1RMBP, push-up, and plank tests to detect change over 6-months. Intraclass correlation coefficients (ICC) and 95% confidence intervals (95% CI) were used to determine intra- and inter-rater reliability—one-way random models for inter-rater and two-way mixed for intra-rater. RESULTS: Standard push-ups showed a medium correlation to 1RMBP at baseline (r(50) = .39, p = .01) and 6-months (r(21) = 0.45, p = .03). Modified push-ups showed a small correlation to 1RMBP at baseline (r(44) = .29, p = .05) and 6-months (r(26) = .16, p = .43). Plank showed a small correlation to 1RMBP at baseline (r(105) = 0.23, p = .02) and 6-months (r(53) = .30, p = .03). Significant increases were detected by 1RMBP (M = 15.3 lbs, SD = 13.6, t(40) = 7.23, p < .001), push-ups (M = 4.9 repetitions, SD = 6.7, t(32) = 4.19, p < .001), and plank (M = 32.9 sec, SD = 37.8, t(38) = 5.44, p < .001) tests. Intra-rater (push-up: ICC = .97, 95% CI [.92, .99] and plank: ICC = .87, 95% CI [.58, .96]) and inter-rater (push-up: ICC = .93, 95% CI [.84, .97] and plank: ICC = .95, 95% CI [.89, .98]) reliability were excellent. CONCLUSION: A remotely-administered standard push-up test is a moderately valid, yet highly sensitive and reliable alternative measure to an in-person test of maximal strength. Remotely-administered knee push-up and plank tests are less valid, but highly sensitive and reliable. Supported by NIH Grant R01CA218093.