. 18 Although electromagnetic tracking systems are a better alternative and would be a suitable technique for assessing functional activities (eg, gait, STS) in a clinical setting, the quantitative analysis of functional activities using optical motion analysis systems is well established, and has
Mohammad Reza Pourahmadi, Ismail Ebrahimi Takamjani, Shapour Jaberzadeh, Javad Sarrafzadeh, Mohammad Ali Sanjari, Rasool Bagheri and Morteza Taghipour
Salman Nazary-Moghadam, Mahyar Salavati, Ali Esteki, Behnam Akhbari, Sohrab Keyhani and Afsaneh Zeinalzadeh
Objectives: The current study assessed the intrasession and intersession reliability of the knee flexion–extension Lyapunov exponent in patients with anterior cruciate ligament deficiency and healthy individuals. Study Design: University research laboratory. Methods: Kinematic data were collected in 14 patients with anterior cruciate ligament deficiency and 14 healthy individuals walked on a treadmill at a self-selected, low, and high speed, with and without cognitive load. The intraclass correlation coefficient, standard error of measurement, minimal metrically detectable change, and percentage of coefficient of variation were calculated to assess the reliability. Results: The knee flexion–extension Lyapunov exponent had high intrasession reliability, with intraclass correlation coefficients ranging from .83 to .98. In addition, the intersession intraclass correlation coefficient values of these measurements ranged from .35 to .85 regardless of group, gait speed, and dual tasking. In general, relative and absolute reliability were higher in the patients with anterior cruciate ligament deficiency than in the healthy individuals. Conclusions: Although knee flexion–extension Lyapunov exponent demonstrates good intrasession reliability, its low intersession reliability indicates that changes of these measurements between different days should be interpreted with caution.
Kai-Yu Ho, Brenda Benson Deaver, Tyrel Nelson and Catherine Turner
reinjuries. Due to the kinematic deviations following ACLR, it is critical to identify those deficits in clinical practice. Three-dimensional (3D) motion analysis is considered most accurate for evaluating kinematics during dynamic movements; however, it requires expensive equipment, designated space, and
Kathryn Mills, Aula Idris, Thu-An Pham, John Porte, Mark Wiggins and Manolya Kavakli
cameras with the game sensor, the DVJs could not be assessed by the VR game and 3D motion analysis concurrently. To avoid potential learning effects, the order of testing was fixed such that 3 DVJs were assessed first by the 3D motion analysis and then repeated with the game. All participants were
Aaron Nelson, Nathan Koslakiewicz and Thomas Gus Almonroeder
trials. Marker clusters were also applied to the heel counter of each shoe to track the foot. A standing calibration trial was conducted with all markers in place. The 3D positions of the markers were recorded at 200 Hz with a 10-camera system (Motion Analysis Inc, Santa Rosa, CA). Calibration markers
Eric P. Scibek, Matthew F. Moran and Susan L. Edmond
Context: The deep squat (DS) test is a component of the functional movement screen, which is used to assess the quality of fundamental movement patterns; however, the accuracy of the DS has not been studied. The DS is a complex, total body movement pattern with evaluation required at several points along the kinematic chain. Objective: To assess the accuracy of DS scoring by an athletic trainer, physical therapist, and exercise science professional via a comparative analysis with kinematic data (KD) and to identify scoring criteria that would improve agreement between raters and KD scores. Design: Cross-sectional study. Setting: Motion analysis laboratory. Participants: A rater from each of 3 movement science disciplines rated the DS of 23 male college athletes (20.3 [1.2] y; 70.5 [3.5] kg). Interventions: Subjects were outfitted with reflective markers and asked to perform the DS. The DS performance was scored by 3 raters and kinematic analysis. Subsequently, the optimal set of criteria that minimized the difference between mode rater score and KD was determined via a Nelder–Mead simplex optimization routine. Main Outcome Measures: Intraclass correlation coefficients (ICCs) were calculated using SPSS (version 23; IBM, Armonk, NY) to determine tester agreement with the KD score and between the mode score and KD score. Results: Agreement was poor for the athletic trainer (ICC = .387), physical therapist (ICC = .298), exercise science professional (ICC = .378), and raters’ DS scores when compared with the KD. Agreement was poor for the mode score when compared with KD prior to optimization and good following optimization (ICC = .830), thereby allowing identification of specific scoring errors. Conclusions: Agreement for DS scores is poor when compared with KD; however, it may be improved with optimization of DS scoring criteria.
Thomas G. Almonroeder, Emily Watkins and Tricia Widenhoefer
Context: The bodyweight squat exercise is a common component for treatment and prevention of patellofemoral pain; however, it can also place a high load on the patellofemoral joint. Restricting anterior motion of the knees relative to the toes during squatting appears to reduce patellofemoral loading. However, exercise professionals typically rely on verbal instructions to alter squat technique. Objective: To evaluate the influence of verbal instructions regarding squat technique on patellofemoral joint loading. Design: Cross-sectional study. Setting: Motion analysis laboratory. Participants: Eleven uninjured females. Intervention: Participants performed bodyweight squats before (baseline) and after receiving verbal instructions to limit anterior knee motion. Two different types of verbal instruction were used, one intended to promote an internal focus of attention and the other intended to promote an external focus of attention. Three-dimensional kinematics and kinetics were recorded using a multicamera system and force plate. Main Outcome Measures: Sagittal plane patellofemoral joint forces and stress were estimated using a musculoskeletal model. Results: Participants demonstrated a reduction in patellofemoral joint forces (35.4 vs 31.3 N/kg; P = .01) and stress (10.7 vs 9.2 mPa; P = .002) after receiving instructions promoting an internal focus of attention, compared with their baseline trials. Participants also demonstrated a reduction in patellofemoral joint forces (35.4 vs 32.3 N/kg; P = .03) and stress (10.7 vs 9.6 mPa; P = .04) after receiving instructions promoting an external focus of attention (vs baseline). However, there were no significant differences in patellofemoral forces (P = .84) or stress (P = .41) for trials performed with an internal versus external attentional focus. Conclusion: It appears that verbal instruction regarding knee position influences patellofemoral joint loading during squatting.
Oliver Silverson, Nicole Cascia, Carolyn M. Hettrich, Matt Hoch and Tim Uhl
assessment methods requiring software or computer analysis • Involved invasive procedures as a means to measure scapular movement • Used 3D motion analysis methods as the only method of evaluation • Did not include reliability as an outcome of the study • Included stroke or palsy patients • Reported on
Shona L. Halson, Alan G. Hahn and Aaron J. Coutts
high reliability but low ecological validity, while field assessments may have lower reliability but strong ecological validity. With the advent of wearable technologies, markerless motion-analysis systems, and sophisticated competition-analysis tools, there has been a rapid expansion of the ability to
Nickolai Martonick, Kimber Kober, Abigail Watkins, Amanda DiEnno, Carmen Perez, Ashlie Renfro, Songah Chae and Russell Baker
around 2 axis: anterioposterior and mediolateral. 3D motion analysis and force plate data were used to analyze hip and knee kinematics and kinetics. Kinematics were analyzed for peak angles and peak angular velocity, while kinetics were analyzed for peak forces and moments at the hip and knee. DKV was