scholarly journals Assessing Muscle-Strength Asymmetry via a Unilateral-Stance Isometric Midthigh Pull

2017 ◽  
Vol 12 (4) ◽  
pp. 505-511 ◽  
Author(s):  
Thomas Dos’Santos ◽  
Christopher Thomas ◽  
Paul A. Jones ◽  
Paul Comfort
Keyword(s):  
College Athletes ◽  
Isometric Force ◽  
Intraclass Correlation ◽  
Force Plate ◽  
Correlation Coefficients ◽  
Rugby League ◽  
Intraclass Correlation Coefficients ◽  
Male College ◽  
Strength Asymmetry ◽  
Force Time

Purpose:To investigate the within-session reliability of bilateral- and unilateral-stance isometric midthigh-pull (IMTP) force–time characteristics including peak force (PF), relative PF, and impulse at time bands (0–100, 0–200, 0–250, and 0–300 milliseconds) and to compare isometric force–time characteristics between right and left and dominant (D) and nondominant (ND) limbs.Methods:Professional male rugby league and multisport male college athletes (N = 54; age, 23.4 ± 4.2 y; height, 1.80 ± 0.05 m; mass, 88.9 ± 12.9 kg) performed 3 bilateral IMTP trials and 6 unilateral-stance IMTP trials (3 per leg) on a force plate sampling at 600 Hz.Results:Intraclass correlation coefficients (ICCs) and coefficients of variation (CVs) demonstrated high within-session reliability for bilateral and unilateral IMTP PF (ICC = .94, CV = 4.7–5.5%). Lower reliability measures and greater variability were observed for bilateral and unilateral IMTP impulse at time bands (ICC = .81–.88, CV = 7.7–11.8%). Paired-sample t tests and Cohen d effect sizes revealed no significant differences for all isometric force–time characteristics between right and left limbs in male college athletes (P >.05, d ≤ 0.32) and professional rugby league players (P > .05, d ≤ 0.11); however, significant differences were found between D and ND limbs in male college athletes (P < .001, d = 0.43–0.91) and professional rugby league players (P < .001, d = 0.27–0.46).Conclusion:This study demonstrated high within-session reliability for unilateral-stance IMTP PF, revealing significant differences in isometric force–time characteristics between D and ND limbs in male athletes.

scholarly journals Validity and Repeatability of Single-Sensor Loadsol Insoles during Landing

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4082 ◽  
Author(s):  
Alexander Peebles ◽  
Lindsay Maguire ◽  
Kristen Renner ◽  
Robin Queen
Keyword(s):  
Cruciate Ligament ◽  
Intraclass Correlation ◽  
Force Plate ◽  
Correlation Coefficients ◽  
Recreational Athletes ◽  
Intraclass Correlation Coefficients ◽  
Anterior Cruciate Ligament Injuries ◽  
Patients At Risk ◽  
Single Sensor ◽  
Anterior Cruciate

Clinically feasible methods for quantifying landing kinetics could help identify patients at risk for secondary anterior cruciate ligament injuries. The purpose of this study was to evaluate the validity and between-day repeatability of the loadsol insole during a single-hop and bilateral stop-jump. Thirty healthy recreational athletes completed seven single-hops and seven stop-jumps while simultaneous loadsol (100 Hz) and force plate (1920 Hz) measurements were recorded. Peak impact force, loading rate, and impulse were computed for the dominant limb, and limb symmetry was calculated between limbs for each measure. All outcomes were compared between the loadsol and force plate using intraclass correlation coefficients (ICC) and Bland–Altman plots. Fifteen participants completed a second day of testing to assess between-day repeatability of the loadsol. Finally, an additional 14 participants completed the first day of testing only to assess the validity of the newest generation loadsol, which sampled at 200 Hz. At 100 Hz, validity ICC results were moderate to excellent (0.686–0.982), and repeatability ICC results were moderate to excellent (0.616–0.928). The 200 Hz loadsol demonstrated improved validity ICC (0.765–0.987). Bland–Altman plots revealed that the loadsol underestimated load measures. However, this bias was not observed for symmetry outcomes. The loadsol device is a valid and repeatable tool for evaluating kinetics during landing.

Reliability of Maximum Isometric Force-Time Parameters during a Leg Press Test in Pubertal Basketball Players

2002 ◽  
Vol 14 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Panagiotis Ioakimidis ◽  
Vasilios Gerodimos ◽  
Eleftherios Kellis ◽  
Spiros Kellis
Keyword(s):  
Isometric Force ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Basketball Players ◽  
Leg Press ◽  
Maximal Force ◽  
Maximum Isometric Force ◽  
Time Parameters ◽  
Relative Scale ◽  
Force Time

Fifteen young basketball players (aged 14.4 – 0.5 yrs) underwent two identical testing sessions spaced one week apart, to determine the reliability of maximum isometric force and force-time parameters during a maximal bilateral isometric leg press effort. The maximal isometric force (MIF), the ratio of maximal force to time (TMIF) to attain maximal force (ARMIF), starting strength (F50), and on a relative scale the time taken to increase the force from 10% to 30%, 60%, and 90% of maximal force were calculated. High intraclass correlation coefficients (ICC) were found for MIF (0.96), ARMIF (0.85), and F50 (0.90). On the relative scale, the ICCs for the times to produce 30%, 60%, and 90% of maximum force were 0.94, 0.95, 0.95, respectively. The present results indicate that maximum isometric force and the force-time parameters during a bilateral leg press can be measured reliably in pubertal basketball players.

scholarly journals The Test–Retest Reliability of Bilateral and Unilateral Force Plate–Derived Parameters of the Countermovement Push-Up in Elite Boxers

2020 ◽  
pp. 1-5
Author(s):  
Gemma N. Parry ◽  
Lee C. Herrington ◽  
Ian G. Horsley ◽  
Ian Gatt
Keyword(s):  
Upper Limb ◽  
Coefficient Of Variation ◽  
Athletic Performance ◽  
Intraclass Correlation ◽  
Force Plate ◽  
Correlation Coefficients ◽  
Vertical Stiffness ◽  
Intraclass Correlation Coefficients ◽  
Test Retest Reliability ◽  
Push Up

Context: Maximal power describes the ability to immediately produce power with the maximal velocity at the point of release, impact, and/or take off—the greater an athlete’s ability to produce maximal power, the greater the improvement of athletic performance. In reference to boxing performance, regular consistent production of high muscular power during punching is considered an essential prerequisite. Despite the importance of upper limb power to athletic performance, presently, there is no gold standard test for upper limb force development performance. Objective: To investigate the test–retest reliability of the force plate–derived measures of countermovement push-up in elite boxers. Design: Test–retest design. Setting: High Performance Olympic Training Center. Participants: Eighteen elite Olympic boxers (age = 23 [3] y; height = 1.68 [0.39] m; body mass = 70.0 [17] kg). Intervention: Participants performed 5 repetitions of countermovement push-up trials on FD4000 Forcedeck dual force platforms on 2 separate test occasions 7 days apart. Main Outcome Measures: Peak force, mean force, flight time, rate of force development, impulse, and vertical stiffness of the bilateral and unilateral limbs from the force–time curve. Results: No significant differences between the 2 trial occasions for any of the derived bilateral or unilateral performance measures. Intraclass correlation coefficients indicated moderate to high reliability for performance parameters (intraclass correlation coefficients = .68–.98) and low coefficient of variation (3%–10%) apart from vertical stiffness (coefficient of variation = 16.5%–25%). Mean force demonstrated the greatest reliability (coefficient of variation = 3%). In contrast, no significant differences (P < .001) were noted between left and right limbs (P = .005–.791), or between orthodox or southpaw boxing styles (P = .19–.95). Conclusion: Force platform–derived kinetic bilateral and unilateral parameters of countermovement push-up are reliable measures of upper limb power performance in elite-level boxers; results suggest unilateral differences within the bilateral condition are not the norm for an elite boxing cohort.

scholarly journals The 10/5 Repeated Jumps Test: Are 10 Repetitions and Three Trials Necessary?

Biomechanics ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 1-14
Author(s):  
Callum Stratford ◽  
Thomas Dos’Santos ◽  
John J. McMahon
Keyword(s):  
Repeated Measures ◽  
Intraclass Correlation ◽  
Force Plate ◽  
Correlation Coefficients ◽  
Pairwise Comparisons ◽  
Strength Index ◽  
Intraclass Correlation Coefficients ◽  
Coefficients Of Variation ◽  
Repeated Measures Analysis ◽  
Ground Contact Time

The purpose of this study was to identify whether ten repetitions and three trials were necessary to achieve stability in peak reactive strength index (RSI) during the 10/5 repeated jumps test (RJT). Twenty-five males, from multiple sports, performed three trials of the RJT on an in-ground force plate, with 90 seconds’ rest between trials. Intraclass correlation coefficients (ICC = 0.916–0.986) and coefficients of variation (CV ≤ 14.5%) were considered acceptable for all variables. Repeated-measures analysis of variance and Freidman’s tests revealed large and significant differences (p ≤ 0.006, η2 = 0.159–0.434, power ≥ 0.859) in ground contact time (GCT), jump height (JH), and subsequently RSI both between trials and repetitions. Pairwise comparisons revealed that repetitions 1–3 produced longer GCTs (p ≤ 0.05, d = 0.41–1.40), lower JHs (p ≤ 0.05, d = 0.31–0.56), and lower RSI values (p ≤ 0.05, d = 0.35–1.24). The shortest GCTs, greatest JHs and greater RSIs occurred between repetitions 7 and 10, with approximately 60% of peak RSIs occurring during these ranges. The sequential estimate technique revealed that seven repetitions were needed to attain stability in mean peak RSI. Non-significant (p = 0.554) and negligible differences (d ≤ 0.09) in the five best RSIs between trials were noted. One trial of the 10/5 RJT is sufficient to evaluate peak RSI in athletes and should reduce data collection time and fatigue.

scholarly journals Identifying Reliable and Relatable Force–Time Metrics in Athletes—Considerations for the Isometric Mid-Thigh Pull and Countermovement Jump

Sports ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 4
Author(s):  
Justin J. Merrigan ◽  
Jason D. Stone ◽  
W. Guy Hornsby ◽  
Joshua A. Hagen
Keyword(s):  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Division I ◽  
Countermovement Jump ◽  
Mean Power ◽  
Time To Peak ◽  
Intraclass Correlation Coefficients ◽  
Limb Stiffness ◽  
Coefficients Of Variation ◽  
Force Time

The purpose of this study was to evaluate intrasession reliability of countermovement jump (CMJ) and isometric mid-thigh pull (IMTP) force–time characteristics, as well as relationships between CMJ and IMTP metrics. Division I sport and club athletes (n = 112) completed two maximal effort CMJ and IMTP trials, in that order, on force plates. Relative and absolute reliability were assessed using intraclass correlation coefficients (ICCs) > 0.80 and coefficients of variation (CVs) < 10%. Intrasession reliability was acceptable for the majority of the CMJ force–time metrics except for concentric rate of force development (RFD), eccentric impulse and RFD, and lower limb stiffness. The IMTP’s time to peak force, instantaneous force at 150 ms, instantaneous net force, and RFD measures were not reliable. Statistically significant weak to moderate relationships (r = 0.20–0.46) existed between allometrically scaled CMJ and IMTP metrics, with the exception of CMJ eccentric mean power not being related with IMTP performances. A majority of CMJ and IMTP metrics met acceptable reliability standards, except RFD measures which should be used with caution. Provided CMJs and IMTPs are indicative of distinct physical fitness capabilities, it is suggested to monitor athlete performance in both tests via changes in those variables that demonstrate the greatest degree of reliability.

scholarly journals Validity and reliability of innovative field measurements of tibial accelerations and spinal kinematics during cricket fast bowling

2021 ◽  
Author(s):  
Billy Senington ◽  
Raymond Y. Lee ◽  
Jonathan Mark Williams
Keyword(s):  
Inertial Sensors ◽  
Intraclass Correlation ◽  
Force Plate ◽  
Correlation Coefficients ◽  
Field Measurements ◽  
Validity And Reliability ◽  
Minimum Detectable Change ◽  
Intraclass Correlation Coefficients ◽  
Spinal Kinematics

AbstractThe use of inertial sensors in fast bowling analysis may offer a cheaper and portable alternative to current methodologies. However, no previous studies have assessed the validity and reliability of such methods. Therefore, this study aimed to assess the validity and reliability of collecting tibial accelerations and spinal kinematics using inertial sensors during in vivo fast bowling. Thirty-five elite male fast bowlers volunteered for this study. An accelerometer attached to the skin over the tibia was used to determine impacts and inertial sensors over the S1, L1 and T1 spinous processes used to derive the relative kinematics. These measurements were compared to optoelectronic and force plate data for validity analysis. Most acceleration and kinematics variables measured report significant correlations > 0.8 with the corresponding gold standard measurement, with intraclass correlation coefficients greater than 0.7. Low standard error of measurement and consequently small minimum detectable change (MDC) values were also observed. This study demonstrates that inertial sensors are as valid and reliable as current methods of fast bowling analysis and may provide some advantages over traditional methods. The novel metrics and methods described in this study may aid coaches and practitioners in the design and monitoring of fast bowling technique. Graphical abstract Graphical abstract illustrating the synopsis of the findings from this paper.

Reproducibility of Plantar Pressure Distribution Data in Barefoot Running

2008 ◽  
Vol 24 (1) ◽  
pp. 14-23 ◽  
Author(s):  
Christian Maiwald ◽  
Stefan Grau ◽  
Inga Krauss ◽  
Marlene Mauch ◽  
Detlef Axmann ◽  
...  
Keyword(s):  
Root Mean Square ◽  
Plantar Pressure ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Distribution Data ◽  
Mean Square ◽  
Barefoot Running ◽  
Intraclass Correlation Coefficients ◽  
Force Time ◽  
Mean Square Errors

The aim of this study was to provide detailed information on rationales, calculations, and results of common methods used to quantify reproducibility in plantar pressure variables. Recreational runners (N = 95) performed multiple barefoot running trials in a laboratory setup, and pressure variables were analyzed in nine distinct subareas of the foot. Reproducibility was assessed by calculating intraclass correlation coefficients (ICC) and the root mean square error (RMSE). Intraclass correlation coefficients ranged from 0.58 to 0.99, depending on the respective variable and type of ICC. Root mean square errors ranged between 2.3 and 3.1% for relative force–time integrals, between 0.07 and 0.23 for maximum force (Fmax), and between 107 and 278 kPa for maximum pressure (Pmax), depending on the subarea of the foot. Force–time integral variables demonstrated the best within-subject reproducibility. Rear-foot data suffered from slightly increased measurement error and reduced reproducibility compared with the forefoot.

Effect of Knee and Trunk Angle on Kinetic Variables During the Isometric Midthigh Pull: Test–Retest Reliability

2015 ◽  
Vol 10 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Paul Comfort ◽  
Paul. A. Jones ◽  
John J. McMahon ◽  
Robert Newton
Keyword(s):  
Knee Flexion ◽  
Isometric Force ◽  
High Reliability ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Joint Angles ◽  
Force Development ◽  
Intraclass Correlation Coefficients ◽  
Hip Flexion ◽  
Test Retest Reliability

The isometric midthigh pull (IMTP) has been used to monitor changes in force, maximum rate of force development (mRFD), and impulse, with performance in this task being associated with performance in athletic tasks. Numerous postures have been adopted in the literature, which may affect the kinetic variables during the task; therefore, the aim of this investigation was to determine whether different knee-joint angles (120°, 130°, 140°, and 150°) and hip-joint angles (125° and 145°), including the subjects preferred posture, affect force, mRFD, and impulse during the IMTP. Intraclass correlation coefficients demonstrated high within-session reliability (r ≥ .870, P < .001) for all kinetic variables determined in all postures, excluding impulse measures during the 130° knee-flexion, 125° hip-flexion posture, which showed a low to moderate reliability (r = .666–.739, P < .001), while between-sessions testing demonstrated high reliability (r > .819, P < .001) for all kinetic variables. There were no significant differences in peak force (P > .05, Cohen d = 0.037, power = .408), mRFD (P > .05, Cohen d = 0.037, power = .409), or impulse at 100 ms (P > .05, Cohen d = 0.056, power = .609), 200 ms (P > .05, Cohen d = 0.057, power = .624), or 300 ms (P > .05, Cohen d = 0.061, power = .656) across postures. Smallest detectable differences demonstrated that changes in performance of >1.3% in peak isometric force, >10.3% in mRFD, >5.3% in impulse at 100 ms, >4.4% in impulse at 200 ms, and >7.1% in impulse at 300 ms should be considered meaningful, irrespective of posture.

Interobserver Reliability Using the Phonetic Level Evaluation With Severely and Profoundly Hearing-Impaired Children

1991 ◽  
Vol 34 (5) ◽  
pp. 989-999 ◽  
Author(s):  
Stephanie Shaw ◽  
Truman E. Coggins
Keyword(s):  
Interrater Reliability ◽  
Interobserver Reliability ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Hearing Impaired ◽  
Intraclass Correlation Coefficients ◽  
Assessment Measure ◽  
Impaired Children ◽  
Speech Assessment ◽  
Hearing Impaired Children

This study examines whether observers reliably categorize selected speech production behaviors in hearing-impaired children. A group of experienced speech-language pathologists was trained to score the elicited imitations of 5 profoundly and 5 severely hearing-impaired subjects using the Phonetic Level Evaluation (Ling, 1976). Interrater reliability was calculated using intraclass correlation coefficients. Overall, the magnitude of the coefficients was found to be considerably below what would be accepted in published behavioral research. Failure to obtain acceptably high levels of reliability suggests that the Phonetic Level Evaluation may not yet be an accurate and objective speech assessment measure for hearing-impaired children.

scholarly journals Is there a relationship between the overhead press and split jerk maximum performance? Influence of sex

2021 ◽  
pp. 174795412110204
Author(s):  
Marcos A Soriano ◽  
G Gregory Haff ◽  
Paul Comfort ◽  
Francisco J Amaro-Gahete ◽  
Antonio Torres-González ◽  
...  
Keyword(s):  
Confidence Intervals ◽  
Body Mass ◽  
Upper Limb ◽  
High Reliability ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Training Experience ◽  
Maximum Performance ◽  
Repetition Maximum ◽  
Intraclass Correlation Coefficients

The aims of this study were to (I) determine the differences and relationship between the overhead press and split jerk performance in athletes involved in weightlifting training, and (II) explore the magnitude of these differences in one-repetition maximum (1RM) performances between sexes. Sixty-one men (age: 30.4 ± 6.7 years; height: 1.8 ± 0.5 m; body mass 82.5 ± 8.5 kg; weightlifting training experience: 3.7 ± 3.5 yrs) and 21 women (age: 29.5 ± 5.2 yrs; height: 1.7 ± 0.5 m; body mass: 62.6 ± 5.7 kg; weightlifting training experience: 3.0 ± 1.5 yrs) participated. The 1RM performance of the overhead press and split jerk were assessed for all participants, with the overhead press assessed on two occasions to determine between-session reliability. The intraclass correlation coefficients (ICC) and 95% confidence intervals showed a high reliability for the overhead press ICC = 0.98 (0.97 – 0.99). A very strong correlation and significant differences were found between the overhead press and split jerk 1RM performances for all participants (r = 0.90 [0.93 – 0.85], 60.2 ± 18.3 kg, 95.7 ± 29.3 kg, p ≤ 0.001). Men demonstrated stronger correlations between the overhead press and split jerk 1RM performances (r = 0.83 [0.73-0.90], p ≤ 0.001) compared with women (r = 0.56 [0.17-0.80], p = 0.008). These results provide evidence that 1RM performance of the overhead press and split jerk performance are highly related, highlighting the importance of upper-limb strength in the split jerk maximum performance.

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