Validity and Reliability of Thoracic-Mounted Inertial Measurement Units to Derive Gait Characteristics During Running.

Horsley, BJ, Tofari, PJ, Halson, SL, Kemp, JG, Chalkley, D, Cole, MH, Johnston, RD, and Cormack, SJ. Validity and reliability of thoracic-mounted inertial measurement units to derive gait characteristics during running. J Strength Cond Res 38(2): 274-282, 2024-Inertial measurement units (IMUs) attached to the tibia or lumbar spine can be used to analyze running gait but, with team-sports, are often contained in global navigation satellite system (GNSS) units worn on the thoracic spine.

Thoracic-Worn Accelerometers Detect Fatigue-Related Changes in Vertical Stiffness During Sprinting.

Horsley, BJ, Tofari, PJ, Halson, SL, Kemp, JG, Johnston, RD, and Cormack, SJ. Thoracic-worn accelerometers detect fatigue-related changes in vertical stiffness during sprinting. J Strength Cond Res 38(2): 283-289, 2024-Thoracic-mounted accelerometers are valid and reliable for analyzing gait characteristics and may provide the opportunity to assess running-related neuromuscular fatigue (NMF) during training and competition without the need for additional tests, such as a countermovement jump (CMJ).

Reliability of corticospinal excitability and intracortical inhibition in biceps femoris during different contraction modes.

This study aimed to determine the test-retest reliability of a range of transcranial magnetic stimulation (TMS) outcomes in the biceps femoris during isometric, eccentric and concentric contractions. Corticospinal excitability (active motor threshold 120% [AMT120%] and area under recruitment curve [AURC]), short- and long-interval intracortical inhibition (SICI and LICI) and intracortical facilitation (ICF) were assessed from the biceps femoris in 10 participants (age 26.3 ± 6.

Effect of an Isometric or Eccentric Hip Extension Exercise Intervention on Hamstring Strength, Architecture, and Morphology.

Purpose: This study aimed to investigate hamstring architectural, strength, and morphological adaptations after an eccentric or isometric hip extension exercise intervention.

Methods: Twenty-four recreationally active males performed either an eccentric ( n = 12) or an isometric hip extension ( n = 12) exercise intervention, twice per week for 6 wk, followed by a 4-wk detraining period. Biceps femoris long head (BFlh) architecture was assessed pre-intervention, mid-intervention, post-intervention, and post-detraining via two-dimensional ultrasound.

Assessing isometric kicking force and post-match responses using the Kicker test.

This study examined the inter-session reliability of force output from a novel isometric strength assessment protocol (the Kicker); and its suitability to monitor soccer player's combined hip flexion and knee extension force capacity over 72-h post-competitive matches. Reliability (Part-A) testing was completed over three sessions on 20 individuals participating in various sports at a recreational level or higher. Post-match strength response (Part-B) data were collected for 72-h after a game (24-h (+24), 48-h (+48) and 72-h (+72) post-match) in 17 male academy soccer players.

Muscle Activity and Activation in Previously Strain-Injured Lower Limbs: A Systematic Review.

Background: Lower limb muscle strain injury is highly prevalent in running-based sports and is considered a risk factor for recurrent injury. It is possible that differences in muscle activity and activation in previously strain-injured limbs may contribute to the elevated risk of reinjury.

Objectives: To systematically review available literature investigating whether muscle activity and/or activation is different in previously strain-injured muscles compared to contralateral uninjured muscles or uninjured controls.

Does Site Matter? Impact of Inertial Measurement Unit Placement on the Validity and Reliability of Stride Variables During Running: A Systematic Review and Meta-analysis.

Background: Inertial measurement units (IMUs) are used for running gait analysis in a variety of sports. These sensors have been attached at various locations to capture stride data. However, it is unclear if different placement sites affect the derived outcome measures.

Differences in Lower Limb Strength and Structure After 12 Weeks of Resistance, Endurance, and Concurrent Training.

Purpose: To investigate strength and structural adaptations after 12 weeks of resistance, endurance cycling, and concurrent training.

Methods: Thirty-two healthy males undertook 12 weeks of resistance-only (RT; n = 10), endurance-only (END; n = 10), or concurrent resistance and endurance training (CONC; n = 12). Biceps femoris long head (BFlh) architecture, strength (3-lift 1-repetition maximum), and body composition were assessed.

Non-motorized Treadmill Running Is Associated with Higher Cardiometabolic Demands Compared with Overground and Motorized Treadmill Running.

The aim of this study was to compare the cardiometabolic demands of running on a curved non-motorized treadmill (cNMT) with overground (OVR) and motorized treadmill (MOT) running. Fourteen trained male ( = 7) and female ( = 7) runners ([Formula: see text] 56.6 ± 4.

Effect of Prior Injury on Changes to Biceps Femoris Architecture across an Australian Football League Season.

Purpose: To assess in-season alterations of biceps femoris long head (BFlh) fascicle length in elite Australian footballers with and without a history of unilateral hamstring strain injury (HSI) in the past 12 months.

Methods: Thirty elite Australian football players were recruited. Twelve had a history of unilateral HSI.

Self-Paced Team-Sport Match Simulation Results in Reductions in Voluntary Activation and Modifications to Biological, Perceptual, and Performance Measures at Halftime and for up to 96 Hours Postmatch.

Tofari, PJ, Kemp, JG, and Cormack, SJ. Self-paced team-sport match-simulation results in reductions in voluntary activation and modifications to biological, perceptual, and performance measures at halftime and for up to 96 hours postmatch. J Strength Cond Res 32(12): 3561-3572, 2018-Assessing responses to soccer match play is limited by match variability or unrealistic simulations.

Comparison of ergometer- and track-based testing in junior track-sprint cyclists. Implications for talent identification and development.

Talent identification (TID) and talent development (TDE) programmes in track sprint cycling use ergometer- and track-based tests to select junior athletes and assess their development. The purpose of this study was to assess which tests are best at monitoring TID and TDE. Ten male participants (16.

Tactical combat movements: inter-individual variation in performance due to the effects of load carriage.

An examination into the effects of carried military equipment on the performance of two tactical combat movement simulations was conducted. Nineteen Airfield Defence Guards performed a break contact (five 30-m sprints) and a fire and movement simulation (16 6-m bounds) in five load conditions (10-30 kg). Heavier loads significantly increased movement duration on the break contact (0.

Effects of Military Load Carriage on Susceptibility to Enemy Fire During Tactical Combat Movements.

Current military operations require soldiers to carry heavy external loads that are widely acknowledged to impair the ability to move tactically on the battlefield. However, to date, the effect of load on susceptibility to enemy fire (the probability of being hit) has not been examined. Nineteen soldiers completed a break contact simulation (five 30-m sprints commencing every 44 seconds) and a fire and movement simulation (sixteen 6-m bounds commencing every 20 seconds) in each of the 5 load conditions (ranging from 9.

Reliability of measures of quadriceps muscle function using magnetic stimulation.

Introduction: Magnetic stimulation can be used to assess muscle function by calculating voluntary activation using an interpolated twitch during maximal voluntary contractions (MVCs) and control twitches to potentiated muscle. In this study we assessed the reliability of torque, electromyography (EMG), and voluntary activation variables.

Methods: Fifteen men completed 5 testing sessions (2 familiarization and 3 reliability trials) to assess quadriceps femoris muscle function.

Changes in Running Performance After Four Weeks of Interval Hypoxic Training in Australian Footballers: A Single-Blind Placebo-Controlled Study.

There is a paucity of data examining the impact of high-intensity interval hypoxic training (IHT) on intermittent running performance. This study assessed the effects of IHT on 17 amateur Australian Footballers, who completed 8 interval treadmill running sessions (IHT [FIO2 = 15.1%] or PLACEBO) over 4 weeks, in addition to normoxic football (2 per week) and resistance (2 per week) training sessions.

A self-paced intermittent protocol on a non-motorised treadmill: a reliable alternative to assessing team-sport running performance.

This study assessed the reliability of a 'self-paced' 30-min, team-sport running protocol on a Woodway Curve 3.0 non-motorised treadmill (NMT). Ten male team-sport athletes (20.

A quantification of the physiological demands of the army emergency responder in the Australian army.

The Australian Defence Force is reviewing the physical demands of all employment categories in the Australian Army to establish valid and legally defensible assessments. The current assessments, performed in physical training attire, are not specific to job demands. Moreover, the fitness standards decrease based on age and are lower for females, and as job requirements are constant, these assessments are counterintuitive.