scholarly journals Tibial Accelerations During the Single-Leg Hop Test: Influence of Fixation

2020 ◽  
pp. 1-4
Author(s):  
Hannah W. Tucker ◽  
Emily R. Tobin ◽  
Matthew F. Moran
Keyword(s):  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Repeated Measures ◽  
Inertial Measurement Unit ◽  
Intraclass Correlation ◽  
Return To Sport ◽  
Fixation Method ◽  
Measurement Unit ◽  
Inertial Measurement ◽  
Hop Test

Context: Performance on single-leg hopping (SLH) assessments is commonly included within return-to-sport criteria for rehabilitating athletes. Triaxial accelerometers have been used to quantify impact loading in a variety of movements, including hopping; however, they have never been attached to the tibia during SLH, and their method of fixation has not been investigated. Objective: The purpose of this study was to quantify triaxial accelerations and evaluate the influence of the fixation method of a lightweight inertial measurement unit (Blue Trident) mounted to the tibia during SLH performance. Design: Single cohort, repeated-measures experimental design. Participants: Sixteen healthy participants (10 females and 6 males; 20 [0.9] y; 1.67 [0.08] m; 66.0 [8.5] kg) met the inclusion criteria, volunteered, and completed this study. Interventions: Participants performed 2 sets of 3 SLH trials with an inertial measurement unit (1500 Hz) fixated to the tibia, each set with 1 of 2 attachment methods (double-sided tape [DST] with athletic tape and silicon strap [SS] with Velcro adhesion). Main Outcome Measures: Hop distance, peak tibial acceleration (PTA), time to PTA, and the acceleration slope were assessed during each hop landing. Results: Repeated-measures analysis of variance determined no significant effect of the attachment method on hop metrics (P = .252). Across 3 trials, both fixation methods (DST and SS) had excellent reliability values (intraclass correlation coefficient: .868–.941) for PTA and acceleration slope but not for time to PTA (intraclass correlation coefficient: .397–.768). The PTA for DST (27.22 [7.94] g) and SS (26.21 [10.48] g) was comparable and had a moderate, positive relationship (DST: r = .72, P < .01; SS: r = .77, P < .01) to SLH distance. Conclusions: Tibial inertial measurement units with triaxial accelerometers can reliably assess PTA during performance of the SLH, and SS is a viable alternative tibial attachment to DST.

scholarly journals Valid and Reliable Barbell Velocity Estimation Using an Inertial Measurement Unit

2021 ◽  
Vol 18 (17) ◽  
pp. 9170
Author(s):  
Steffen Held ◽  
Ludwig Rappelt ◽  
Jan-Philip Deutsch ◽  
Lars Donath
Keyword(s):  
Inertial Measurement Unit ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Velocity Estimation ◽  
Measurement Unit ◽  
Systematic Bias ◽  
Validity And Reliability ◽  
Inertial Measurement ◽  
Intraclass Correlation Coefficients ◽  
Reliability Indicators

The accurate assessment of the mean concentric barbell velocity (MCV) and its displacement are crucial aspects of resistance training. Therefore, the validity and reliability indicators of an easy-to-use inertial measurement unit (VmaxPro®) were examined. Nineteen trained males (23.1 ± 3.2 years, 1.78 ± 0.08 m, 75.8 ± 9.8 kg; Squat 1-Repetition maximum (1RM): 114.8 ± 24.5 kg) performed squats and hip thrusts (3–5 sets, 30 repetitions total, 75% 1RM) on two separate days. The MCV and displacement were simultaneously measured using VmaxPro® and a linear position transducer (Speed4Lift®). Good to excellent intraclass correlation coefficients (0.91 < ICC < 0.96) with a small systematic bias (p < 0.001; ηp2 < 0.50) for squats (0.01 ± 0.04 m·s−1) and hip thrusts (0.01 ± 0.05 m·s−1) and a low limit of agreement (LoA < 0.12 m·s−1) indicated an acceptable validity. The within- and between-day reliability of the MCV revealed good ICCs (0.55 < ICC < 0.91) and a low LoA (<0.16 m·s−1). Although the displacement revealed a systematic bias during squats (p < 0.001; ηp2 < 0.10; 3.4 ± 3.4 cm), no bias was detectable during hip thrusts (p = 0.784; ηp2 < 0.001; 0.3 ± 3.3 cm). The displacement showed moderate to good ICCs (0.43 to 0.95) but a high LoA (7.8 to 10.7 cm) for the validity and (within- and between-day) reliability of squats and hip thrusts. The VmaxPro® is considered to be a valid and reliable tool for the MCV assessment.

scholarly journals Validity and sensitivity of an inertial measurement unit-driven biomechanical model of motor variability for gait

2021 ◽  
Author(s):  
Christopher Bailey ◽  
Thomas Uchida ◽  
Julie Nantel ◽  
Ryan Graham
Keyword(s):  
Inertial Measurement Unit ◽  
Intraclass Correlation ◽  
Biomechanical Model ◽  
Measurement Unit ◽  
Local Dynamic ◽  
Joint Angles ◽  
Motor Variability ◽  
Arm Swing ◽  
Inertial Measurement ◽  
Local Dynamic Stability

Motor variability in gait is frequently linked to fall risk, yet field-based biomechanical joint evaluations are scarce. We evaluated the validity and sensitivity of an inertial measurement unit (IMU)-driven biomechanical model of joint angle variability for gait. Fourteen healthy young adults completed seven-minute trials of treadmill gait at several speeds and arm swing amplitudes. Joint kinematics were estimated by IMU- and optoelectronic-based models using OpenSim. We calculated range of motion (ROM), magnitude of variability (meanSD), local dynamic stability (λmax), persistence of ROM fluctuations (DFAα), and regularity (SaEn) of each angle over 200 continuous strides, and evaluated model accuracy (e.g., RMSD: root mean square difference), consistency (ICC2,1: intraclass correlation), biases, limits of agreement, and sensitivity to within-participant gait responses (effects of Speed and Swing). RMSDs of joint angles were 1.7–7.5° (pooled mean of 4.8°), excluding ankle inversion. ICCs were mostly good–excellent in the primary plane of motion for ROM and in all planes for meanSD and λmax, but were poor–moderate for DFAα and SaEn. Modeled Speed and Swing responses for ROM, meanSD, and λmax were similar. Results suggest that the IMU-driven model is valid and sensitive for field-based assessments of joint angles and several motor variability features.

scholarly journals Intra-rater reliability of transversus abdominis measurement by a novice examiner: Comparison of “freehand” to “probe force device” method of real-time ultrasound imaging

Ultrasound ◽  
2019 ◽  
Vol 27 (3) ◽  
pp. 156-166 ◽  
Author(s):  
Vanessa L Kennedy ◽  
Carol A Flavell ◽  
Kenji Doma
Keyword(s):  
Measurement Error ◽  
Real Time ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Coefficient Of Variation ◽  
Repeated Measures ◽  
Intraclass Correlation ◽  
Transversus Abdominis ◽  
Rater Reliability ◽  
Transverse Abdominis

A “free hand” real-time-ultrasound method is commonly applied to measure transversus abdominis. Potentially, this increases transversus abdominis measurement error due to uncontrolled variability in probe to skin force, inclination, and roll, particularly for novice examiners. This single-group repeated-measures reliability study compared the intra-rater reliability of transversus abdominis thickness and activation measurement by a novice examiner between free hand and a standardized probe force device method. The examiner captured ultrasound videos of transversus abdominis in a single session in healthy participants ( n =  33). Free hand ultrasound featured uncontrolled probe force, inclination, and roll, while probe force device method ultrasound standardized these parameters. Images of transversus abdominis at rest and contracted were measured and transversus abdominis activation calculated. Intraclass correlation coefficient, coefficient of variation, standard error of measurement, and worthwhile differences were calculated. The probe force device method resulted in greater reliability (intraclass correlation coefficient = 0.75–0.96) and lower measurement error (coefficient of variation = 8.89–28.7%) compared to free hand (intraclass correlation coefficient = 0.63–0.93; coefficient of variation = 6.52–29.4%). Reliability was good for all measurements except free hand TrA-C, which was moderate. TrA-C had the lowest reliability, followed by contracted thickness of the transverse abdominis, with resting thickness of the transverse abdominis being highest. Worthwhile differences were lower using a probe force device method versus free hand for resting thickness of the transverse abdominis and contracted thickness of the transverse abdominis and similar for TrA-C. Standardization using probe force device method ultrasound to measure transversus abdominis improved intra-rater reliability in a novice examiner. Use of a probe force device method is recommended to improve reliability through reduced sources of measurement error. Probe force device method intra- and inter-rater reliability in examiners of varying experience, in clinical populations, and to visualize other structures merits exploration.

Reliability of 5 Novel Reaction Time and Cognitive Load Protocols

2018 ◽  
Vol 27 (5) ◽  
Author(s):  
Kelsey Picha ◽  
Carolina Quintana ◽  
Amanda Glueck ◽  
Matt Hoch ◽  
Nicholas R. Heebner ◽  
...  
Keyword(s):  
Reaction Time ◽  
Cognitive Load ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Repeated Measures ◽  
Sports Medicine ◽  
Intraclass Correlation ◽  
Minimal Detectable Change ◽  
Good Reliability ◽  
Medicine Research

Context: Reaction time (RT) is crucial to athletic performance. Therefore, when returning athletes to play following injury, it is important to evaluate RT characteristics ensuring a safe return. The Dynavision D2® system may be utilized as an assessment and rehabilitation aid in the determination of RT under various levels of cognitive load. Previous research has demonstrated good reliability of simple protocols when assessed following a 24- to 48-hour test–retest window. Expanding reliable test–retest intervals may further refine novel RT protocols for use as a diagnostic and rehabilitation tool. Objective: To investigate the test–retest reliability of a battery of 5 novel RT protocols at different time intervals. Design: Repeated measures/reliability. Setting: Interdisciplinary sports medicine research laboratory. Participants: Thirty healthy individuals. Methods: Participants completed a battery of protocols increasing in difficulty in terms of reaction speed requirement and cognitive load. Prior to testing, participants were provided 3 familiarization trials. All protocols required participants to hit as many lights as quickly as possible in 60 seconds. After completing the initial testing session (session 1), participants waited 1 hour before completing the second session (session 2). Approximately 2 weeks later (average 14 [4] d), the participants completed the same battery of tasks for the third session (session 3). Main Outcome Measures: The intraclass correlation coefficient, standard error of measurement, minimal detectable change, and repeated-measures analysis of variance were calculated for RT. Results: The intraclass correlation coefficient values for each of the 5 protocols illustrated good to excellent reliability between sessions 1, 2, and 3 (.75–.90). There were no significant differences across time points (F < 0.105, P > .05). Conclusions: The 1-hour and 14-day test–retest intervals are reliable for clinical assessment, expanding the time frames previously reported in the literature of when assessments can be completed reliably. This study provides novel protocols that challenge cognition in unique ways.

scholarly journals Validity and Sensitivity of an Inertial Measurement Unit-Driven Biomechanical Model of Motor Variability for Gait

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7690
Author(s):  
Christopher A. Bailey ◽  
Thomas K. Uchida ◽  
Julie Nantel ◽  
Ryan B. Graham
Keyword(s):  
Dynamic Stability ◽  
Inertial Measurement Unit ◽  
Joint Angle ◽  
Intraclass Correlation ◽  
Biomechanical Model ◽  
Measurement Unit ◽  
Local Dynamic ◽  
Motor Variability ◽  
Inertial Measurement ◽  
Local Dynamic Stability

Motor variability in gait is frequently linked to fall risk, yet field-based biomechanical joint evaluations are scarce. We evaluated the validity and sensitivity of an inertial measurement unit (IMU)-driven biomechanical model of joint angle variability for gait. Fourteen healthy young adults completed seven-minute trials of treadmill gait at several speeds and arm swing amplitudes. Trunk, pelvis, and lower-limb joint kinematics were estimated by IMU- and optoelectronic-based models using OpenSim. We calculated range of motion (ROM), magnitude of variability (meanSD), local dynamic stability (λmax), persistence of ROM fluctuations (DFAα), and regularity (SaEn) of each angle over 200 continuous strides, and evaluated model accuracy (RMSD: root mean square difference), consistency (ICC2,1: intraclass correlation), biases, limits of agreement, and sensitivity to within-participant gait responses (effects of speed and swing). RMSDs of joint angles were 1.7–7.5° (pooled mean of 4.8°), excluding ankle inversion. ICCs were mostly good to excellent in the primary plane of motion for ROM and in all planes for meanSD and λmax, but were poor to moderate for DFAα and SaEn. Modelled speed and swing responses for ROM, meanSD, and λmax were similar. Results suggest that the IMU-driven model is valid and sensitive for field-based assessments of joint angle time series, ROM in the primary plane of motion, magnitude of variability, and local dynamic stability.

Parallel Comparison of Grip Strength Measures Obtained with a Microfet 4 and a Jamar Dynamometer

2005 ◽  
Vol 100 (3) ◽  
pp. 795-798 ◽  
Author(s):  
Richard W. Bohannon
Keyword(s):  
Grip Strength ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Repeated Measures ◽  
Intraclass Correlation ◽  
Highly Correlated ◽  
Jamar Dynamometer

Repeated measures of grip strength obtained bilaterally with a Jamar and a MicroFET 4 dynamometer were compared. Measurements obtained with the MicroFET 4 tended to be slightly (2.2–3.1 lb.) higher but were highly correlated ( r ≥ .96) with those obtained with the Jamar. Parallel reliability for the two devices was excellent (intraclass correlation coefficient ≥ .96). Although clinicians should be cautious about using the devices interchangeably, the MicroFET 4 appears to be a legitimate alternative to the Jamar dynamometer.

Validity and Reliability of a New Device to Measure Type of Actions in Indoor Sports

2020 ◽  
Author(s):  
Carlos Lago-Fuentes ◽  
Paolo Aiello ◽  
Mauro Testa ◽  
Iker Muñoz ◽  
Marcos Mecías Calvo
Keyword(s):  
Coefficient Of Variation ◽  
Inertial Measurement Unit ◽  
High Reliability ◽  
Intraclass Correlation ◽  
Measurement Unit ◽  
Validity And Reliability ◽  
Inertial Measurement ◽  
New Device ◽  
Standing Up ◽  
Indoor Sports

AbstractThe purpose of this study was to analyze the validity and the reliability of the intensity ranges, number of actions and changes of direction measured by a commercial inertial measurement unit. Eleven elite youth futsal players performed a circuit with different type of displacements as sprinting, running at low-medium intensity, standing up and changes of direction. Data recorded by the Overtraq system were compared with video-analyzer during the six trials of each player. Standard error mean, Intraclass Correlation Coeficient and Coefficient of variation, were calculated to analyze the reliability of the device, as well as the Root Mean Square Error and Confidence Interval with correlation of Pearson for its validity. The results reported good validity for three intensity ranges (R2>0.7) with high reliability (Intraclass Correlation Coeficient: 0.8–0.9), especially for high intensity actions (Intraclass Correlation Coeficient: 0.95, Coefficient of Variation: 3.06%). Furthermore, the validity for the number of different actions was almost perfect (96.3–100%), with only small differences regarding changes of activity (mean error: 2.0%). The Overtraq system can be considered as a valid and reliable technology for measuring and monitoring actions at different intensities and changes of direction in futsal, likewise common actions for other indoor sports.

scholarly journals New Tracking System of Human Scapula Using Ultrasonography and Motion Sensors: A Descriptive Test–Retest Design

2019 ◽  
Vol 28 (7) ◽  
Author(s):  
Manuel Trinidad-Fernández ◽  
Manuel González-Sánchez ◽  
Antonio I. Cuesta-Vargas
Keyword(s):  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Ultrasound Imaging ◽  
Repeated Measures ◽  
External Rotation ◽  
Pearson Correlation ◽  
Intraclass Correlation ◽  
New Method

Context: Several studies have shown that the kinematics of the scapula is altered in many disorders that affect the shoulder. Description of scapular motion in the chest continues to be a scientific and clinical challenge. Objective: To check the validity and reliability of a new, minimally invasive method of tracking the internal and external rotation of the scapula using ultrasound imaging combined with the signal provided by a 3-dimensional electromagnetic sensor. Design: A cross-sectional study with a repeated-measures descriptive test–retest design was employed to evaluate this new tracking method. The new method was validated in vitro and the reliability of data over repeated measures between scapula positions was calculated in vivo. Setting: University laboratory. Participants: A total of 30 healthy men and women. Main Outcome Measure: The validation of the scapula rotation tracking using the in vitro model was calculated by Pearson correlation test between a 2-dimensional cross-correlation algorithm of the new method and another software image. The reliability of the tracking of the scapula rotation was measured using the intraclass correlation coefficient. Results: In the validation in vitro, the correlation of rotations obtained by the 2 methods was good (r = .77, P = .01). The reliability in vivo had excellent results (intraclass correlation coefficient = .88; 95% confidence interval, .82–.93) in the test–retest analysis of 8 measures. The intrarater analysis of variance test showed no significant differences between the measures (P = .85, F = 0.46). Conclusion: Ultrasound imaging combined with a motion sensor to track the scapula has been shown to be a reliable and valid method for measuring internal and external rotation during separation of the upper limb.

scholarly journals Variability in Baseball Throwing Metrics During a Structured Long-Toss Program: Does One Size Fit All or Should Programs Be Individualized?

2019 ◽  
Vol 11 (6) ◽  
pp. 535-542 ◽  
Author(s):  
Nels D. Leafblad ◽  
Dirk R. Larson ◽  
Glenn S. Fleisig ◽  
Stan Conte ◽  
Stephen A. Fealy ◽  
...  
Keyword(s):  
High School ◽  
Coefficient Of Variation ◽  
Inertial Measurement Unit ◽  
Intraclass Correlation ◽  
Measurement Unit ◽  
Level Of Evidence ◽  
Inertial Measurement ◽  
Ball Velocity ◽  
Maximum Effort ◽  
Level 3

Background: The variability of throwing metrics, particularly elbow torque and ball velocity, during structured long-toss programs is unknown. Hypotheses: (1) Elbow torque and ball velocity would increase as throwers progressed through a structured long-toss program and (2) intrathrower reliability would be high while interthrower reliability would be variable. Study Design: Descriptive laboratory study. Level of Evidence: Level 3. Methods: Sixty healthy high school and collegiate pitchers participated in a structured long-toss program while wearing a validated inertial measurement unit, which measured arm slot, arm velocity, shoulder rotation, and elbow varus torque. Ball velocity was assessed by radar gun. These metrics were compared within and between all pitchers at 90, 120, 150, and 180 ft and maximum effort mound pitching. Intra- and interthrower reliabilities were calculated for each metric at every stage of the program. Results: Ball velocity significantly changed at each progressive throwing distance, but elbow torque did not. Pitching from the mound did not place more torque on the elbow than long-toss throwing from 120 ft and beyond. Intrathrower reliability was excellent (intraclass correlation coefficient >0.75) throughout the progressive long-toss program, especially on the mound. Ninety-one percent of throwers had acceptable interthrower reliability (coefficient of variation <5%) for ball velocity, whereas only 79% of throwers had acceptable interthrower reliability for elbow torque. Conclusion: Based on trends in elbow torque, it may be practical to incorporate pitching from the mound earlier in the program (once a player is comfortable throwing from 120 ft). Ball velocity and elbow torque do not necessarily correlate with one another, so a degree of caution should be exercised when using radar guns to estimate elbow torque. Given the variability in elbow torque between throwers, some athletes would likely benefit from an individualized throwing program. Clinical Relevance: Increased ball velocity does not necessarily equate to increased elbow torque in long-toss. Some individuals would likely benefit from individualized long-toss programs for rehabilitation.

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