A systematic review of the different calculation methods for measuring jump height during the countermovement and drop jump tests (2023)
Journal Article
Xu, J., Turner, A., Comfort, P., Harry, J., McMahon, J., Chavda, S., & Bishop, C. (in press). A systematic review of the different calculation methods for measuring jump height during the countermovement and drop jump tests. Sports Medicine, 11, https://doi.org/10.1007/s40279-023-01828-x

Background
The height obtained during the countermovement jump (CMJ) and drop jump (DJ) tests have been
measured by numerous studies using different calculation methods and pieces of equipment.
However, the differences in calculation methods and e... Read More about A systematic review of the different calculation methods for measuring jump height during the countermovement and drop jump tests.

The Effect of Rest Redistribution on Kinetic and Kinematic Variables During the Countermovement Shrug. (2022)
Journal Article
Meechan, D., McMahon, J. J., Suchomel, T. J., & Comfort, P. (in press). The Effect of Rest Redistribution on Kinetic and Kinematic Variables During the Countermovement Shrug. Journal of Strength and Conditioning Research, 37(7), 1358-1366. https://doi.org/10.1519/JSC.0000000000004238

This study compared the effects of rest redistribution (RR) on kinetic and kinematic variables during the countermovement shrug (CMS). Twenty-one male subjects (age 27.2 ± 3.3. years, height 1.78 ± 0.07 m, body mass 77.2 ±10.6 kg, relative one repeti... Read More about The Effect of Rest Redistribution on Kinetic and Kinematic Variables During the Countermovement Shrug..

Force plate-derived countermovement jump normative data and benchmarks for professional Rugby League players (2022)
Journal Article
McMahon, J., Ripley, N., & Comfort, P. (2022). Force plate-derived countermovement jump normative data and benchmarks for professional Rugby League players. Sensors, 22(22), 8669. https://doi.org/10.3390/s22228669

The countermovement jump (CMJ) is an important test in rugby league (RL), and the force plate is the recommended assessment device, as it permits the calculation of several variables that explain jump strategy, alongside jump height. The purpose of t... Read More about Force plate-derived countermovement jump normative data and benchmarks for professional Rugby League players.

Comparison between methods to estimate bicep femoris fascicle length from three estimation equations using a 10 cm ultrasound probe (2022)
Journal Article
Ripley, N., Comfort, P., & McMahon, J. (2022). Comparison between methods to estimate bicep femoris fascicle length from three estimation equations using a 10 cm ultrasound probe. Measurement in Physical Education and Exercise Science, 27(1), 43-50. https://doi.org/10.1080/1091367X.2022.2063689

The aim of the present study was to determine the reliability and differences between three fascicle length (FL) estimation methods when utilizing a 10-cm ultrasound (US) probe. Thirteen males (24.1 ± 3.8 years, 79.3 ± 14 kg, 179 ± 6.6 cm) participat... Read More about Comparison between methods to estimate bicep femoris fascicle length from three estimation equations using a 10 cm ultrasound probe.

Vertical jump testing in rugby league : a rationale for calculating take-off momentum (2020)
Journal Article
McMahon, J., Lake, J., Ripley, N., & Comfort, P. (2020). Vertical jump testing in rugby league : a rationale for calculating take-off momentum. Journal of Applied Biomechanics, 36(6), 370-374. https://doi.org/10.1123/jab.2020-0100

The purpose of this study was to determine the usefulness of calculating jump take-off momentum in rugby league (RL) by exploring its relationship with sprint momentum, due to the latter being an important attribute of this sport. Twenty-five male RL... Read More about Vertical jump testing in rugby league : a rationale for calculating take-off momentum.

Countermovement jump standards in rugby league : what is a “good” performance? (2020)
Journal Article
McMahon, J., Lake, J., Dos'Santos, T., Jones, P., Thomasson, M., & Comfort, P. (2020). Countermovement jump standards in rugby league : what is a “good” performance?. Journal of Strength and Conditioning Research, 36(6), 1691-1698. https://doi.org/10.1519/JSC.0000000000003697

The countermovement jump (CMJ) is considered an important test in rugby league and the
force platform is the recommended tool for assessing CMJ performance in this cohort. Due to
inconsistent methods applied across previous studies, there is curren... Read More about Countermovement jump standards in rugby league : what is a “good” performance?.

Contribution of eccentric strength to cutting performance in female soccer players (2019)
Journal Article
Jones, P., Dos'Santos, T., McMahon, J., & Graham-Smith, P. (2019). Contribution of eccentric strength to cutting performance in female soccer players. Journal of Strength and Conditioning Research, https://doi.org/10.1519/JSC.0000000000003433

The aim of this study was to examine the contribution of eccentric strength to performance of a 70-90° cutting task (CUT) (time to complete: 5 m approach, 70-90° cut, 3 m exit). Nineteen female soccer players (mean ± SD age, height and mass; 21.6 ± 4... Read More about Contribution of eccentric strength to cutting performance in female soccer players.

Comparison of countermovement jump–derived reactive strength index modified and underpinning force-time variables between super league and championship rugby league players (2019)
Journal Article
McMahon, J., Jones, P., & Comfort, P. (2019). Comparison of countermovement jump–derived reactive strength index modified and underpinning force-time variables between super league and championship rugby league players. Journal of Strength and Conditioning Research, https://doi.org/10.1519/JSC.0000000000003380

The countermovement jump (CMJ) is regularly tested in rugby league (RL), with recent work reporting reactive strength index modified (RSImod) to distinguish between levels of play. Differences in CMJ-derived RSImod and underpinning force-time variabl... Read More about Comparison of countermovement jump–derived reactive strength index modified and underpinning force-time variables between super league and championship rugby league players.

Normalization of early isometric force production as a percentage of peak force during multijoint isometric assessment (2019)
Journal Article
Comfort, P., Dos’Santos, T., Jones, P., McMahon, J., Suchomel, T., Bazyler, C., & Stone, M. (2020). Normalization of early isometric force production as a percentage of peak force during multijoint isometric assessment. International Journal of Sports Physiology and Performance, 15(4), 478-482. https://doi.org/10.1123/ijspp.2019-0217

Purpose: To determine the reliability of early force production (50-, 100-, 150-, 200-, 250 ms) relative to peak force (PF) during an isometric mid-thigh pull (IMTP) and assess the relationships between these variables. Methods: Male collegiate athle... Read More about Normalization of early isometric force production as a percentage of peak force during multijoint isometric assessment.

The effect of load placement on the power production characteristics of three lower extremity jumping exercises (2019)
Journal Article
Suchomel, T. J., McKeever, S. M., Sijuwade, O., Carpenter, L., McMahon, J., Loturco, I., & Comfort, P. (2019). The effect of load placement on the power production characteristics of three lower extremity jumping exercises. Journal of Human Kinetics, 68(1), 109-122. https://doi.org/10.2478/hukin-2019-0060

The purpose of this study was to compare the power production characteristics of the jump squat (JS), hexagonal barbell jump (HEXJ), and jump shrug (JShrug) across a spectrum of relative loads. Fifteen resistance-trained men completed three testing s... Read More about The effect of load placement on the power production characteristics of three lower extremity jumping exercises.

The reliability and validity of the bar-mounted PUSH BandTM 2.0 during bench press with moderate and heavy loads (2019)
Journal Article
Lake, J., Augustus, S., Austin, K., Comfort, P., McMahon, J., Mundy, P., & Haff, G. (2019). The reliability and validity of the bar-mounted PUSH BandTM 2.0 during bench press with moderate and heavy loads. Journal of Sports Sciences, 37(23), 2685-2690. https://doi.org/10.1080/02640414.2019.1656703

The aim of this study was to assess the reliability and validity of the bar-mounted PUSH BandTM 2.0 to determine peak and mean velocity during the bench press exercise with a moderate (60% one repetition maximum [1RM]) and heavy (90% 1RM) load. We di... Read More about The reliability and validity of the bar-mounted PUSH BandTM 2.0 during bench press with moderate and heavy loads.

Changes in dynamic strength index in response to strength training (2018)
Journal Article
Comfort, P., Thomas, C., Dos'Santos, T., Suchomel, T., Jones, P., & McMahon, J. (2018). Changes in dynamic strength index in response to strength training. Sports, 6(4), 176. https://doi.org/10.3390/sports6040176

The primary aim of this investigation was to determine the effects of a four-week period of in-season strength training on the dynamic strength index (DSI). Pre and post a four-week period of strength-based training, twenty-four collegiate athletes (... Read More about Changes in dynamic strength index in response to strength training.

Optimizing Squat Technique—Revisited (2018)
Journal Article
Comfort, P., McMahon, J., & Suchomel, T. J. (2018). Optimizing Squat Technique—Revisited. Strength and Conditioning Journal, 40(6), 68-74. https://doi.org/10.1519/SSC.0000000000000398

The back squat is the cornerstone of many strength and conditioning programs, with increases in back squat strength associated with improvements in athletic performance. A variety of back squat techniques have been described throughout the literature... Read More about Optimizing Squat Technique—Revisited.

Within-subject consistency of unimodal and bimodal force application during the countermovement jump (2018)
Journal Article
Lake, J., & McMahon, J. (2018). Within-subject consistency of unimodal and bimodal force application during the countermovement jump. Sports, 6(4), 143. https://doi.org/10.3390/sports6040143

Countermovement jump (CMJ) force data are often time-normalized so researchers and practitioners can study the effect that sex, training status, and training intervention have on CMJ strategy: the so-called force⁻time curve shape. Data are often coll... Read More about Within-subject consistency of unimodal and bimodal force application during the countermovement jump.

The validity of the Push Band 2.0 during vertical jump performance (2018)
Journal Article
Lake, J., Augustus, S., Austin, K., Mundy, P., McMahon, J., Comfort, P., & Haff, G. (2018). The validity of the Push Band 2.0 during vertical jump performance. Sports, 6(4), 140. https://doi.org/10.3390/sports6040140

The Push Band has the potential to provide a cheap and practical method of measuring velocity and power during countermovement vertical jumping (CMJ). However, very little is known about whether it conforms to laboratory-based gold standards. The aim... Read More about The validity of the Push Band 2.0 during vertical jump performance.

Reliability of and relationship between flight time to contraction time ratio and reactive strength index modified (2018)
Journal Article
McMahon, J., Lake, J., & Comfort, P. (2018). Reliability of and relationship between flight time to contraction time ratio and reactive strength index modified. Sports, 6(3), 81. https://doi.org/10.3390/sports6030081

Countermovement jump (CMJ) force-time testing is commonly used to monitor seasonal alterations in athletes’ CMJ strategy (to infer alterations in neuromuscular function). The flight time to contraction time (FT:CT) ratio and reactive strength index m... Read More about Reliability of and relationship between flight time to contraction time ratio and reactive strength index modified.

Assessing the frequency and magnitude of match impacts accrued during an elite rugby union playing season (2018)
Journal Article
Grainger, A., McMahon, J., & Comfort, P. (2018). Assessing the frequency and magnitude of match impacts accrued during an elite rugby union playing season. International Journal of Performance Analysis in Sport, 18(4), 507-522. https://doi.org/10.1080/24748668.2018.1496392

The aim of this study was to identify position-related differences in absolute and relative match impacts in rugby union. Thirty-eight subjects were tracked, using GPS units containing inertial sensors, across one full playing season (n = 462 data se... Read More about Assessing the frequency and magnitude of match impacts accrued during an elite rugby union playing season.

An investigation into the effects of excluding the catch phase of the power clean on force-time characteristics during isometric and dynamic tasks (2018)
Journal Article
Comfort, P., Dos'Santos, T., Thomas, C., McMahon, J., & Suchomel, T. (2018). An investigation into the effects of excluding the catch phase of the power clean on force-time characteristics during isometric and dynamic tasks. Journal of Strength and Conditioning Research, 32(8), 2116-2129. https://doi.org/10.1519/JSC.0000000000002656

The aims of this study were to compare the effects of the exclusion or inclusion of the catch phase during power clean (PC) derivatives on force-time characteristics during isometric and dynamic tasks, after two 4-week mesocycles of resistance traini... Read More about An investigation into the effects of excluding the catch phase of the power clean on force-time characteristics during isometric and dynamic tasks.

Concurrent validity of a portable force plate using vertical jump force-time characteristics (2018)
Journal Article
Lake, J., Mundy, P., Comfort, P., McMahon, J., Suchomel, T., & Carden, P. (2018). Concurrent validity of a portable force plate using vertical jump force-time characteristics. Journal of Applied Biomechanics, 34(5), 410-413. https://doi.org/10.1123/jab.2017-0371

This study examined concurrent validity of countermovement vertical jump (CMJ) reactive strength index modified and force-time characteristics recorded using a one dimensional portable and laboratory force plate system. Twenty-eight men performed bil... Read More about Concurrent validity of a portable force plate using vertical jump force-time characteristics.

Variability of plyometric and ballistic exercise technique maintains jump performance (2018)
Journal Article
Chandler, P., Greig, M., & McMahon, J. (2018). Variability of plyometric and ballistic exercise technique maintains jump performance. Journal of Strength and Conditioning Research, 32(6), 1571-1582. https://doi.org/10.1519/JSC.0000000000002572

The aim of this study was to investigate changes in vertical jump technique over the course of a training session. Twelve plyometric and ballistic exercise trained male athletes (age = 23.4 ± 4.6 years, body mass = 78.7 ± 18.8 kg, height = 177.1 ± 9.... Read More about Variability of plyometric and ballistic exercise technique maintains jump performance.