Reliability of artificial intelligence-driven markerless motion capture in gait analyses of healthy adults.

The KinaTrax markerless motion capture system, used extensively in the analysis of baseball pitching and hitting, is currently being adapted for use in clinical biomechanics. In clinical and laboratory environments, repeatability is inherent to the quality of any diagnostic tool. The KinaTrax system was assessed on within- and between-session reliability for gait kinematic and spatiotemporal parameters in healthy adults.

Acute effects of Nordic hamstring exercise on ultrasound shear wave elastography.

Aim: The Nordic hamstring curl appears effective in reducing the incidence of injury in physically active young adults, likely through its capacity as an eccentric exercise to increase muscle stiffness. Although eccentric exercises have been shown to increase muscle stiffness, medium- and long-term Nordic hamstring curl training programs have not demonstrated an effect on muscle stiffness. This study examined the acute effects of a single session of Nordic hamstring curls on the stiffness of the biceps femoris, semitendinosus, and semimembranosus muscles using ultrasound shear wave elastography, an accepted method for measuring passive muscle stiffness.

"Caminando y socializando con Happy Older Latinos are Active (HOLA)": Results of a randomized clinical trial to promote health and prevent depression and anxiety in older Latinos.

Objective: This study sought to evaluate the feasibility, acceptability, and preliminary efficacy of the Happy Older Latinos are Active (HOLA) health promotion intervention in a group of older Latinos who were at risk for developing major depressive disorder or generalized anxiety disorder.

Method: Sixty older Latinos age 60+ with subthreshold depression or anxiety were randomized to receive either HOLA (n = 30) or enhanced psychoeducation through control ( = 30). The primary outcomes of interest were feasibility, acceptability, and reduction in depression and anxiety symptom severity.

Knee joint mechanics during gait after anterior cruciate ligament reconstruction using a partial or full thickness quadriceps tendon autograft at 2 years after surgery.

Background: Despite quadriceps weakness in individuals after quadriceps tendon anterior cruciate ligament reconstruction (QT-ACLR), and its association with knee joint mechanics, no studies have addressed gait mechanics in both partial-thickness (PT-Q) and full-thickness (FT-Q) options for QT-ACLR.

Objective: To assess gait mechanics across a QT-ACLR cohort. We hypothesized that QT-ACLR would show changes in knee joint mechanics compared to control participants (CON) and nonoperated limbs.

Velocity-Based-Training Frequency Impacts Changes in Muscle Morphology, Neuromuscular Performance, and Functional Capability in Persons With Parkinson's Disease.

Calaway, C, Walls, K, Levitt, H, Caplan, J, Mann, B, Martinez, K, Gastaldo, R, Haq, I, and Signorile, JF. Velocity-based-training frequency impacts changes in muscle morphology, neuromuscular performance, and functional capability in persons with Parkinson's disease. J Strength Cond Res 39(1): 99-106, 2025-Velocity-based training (VBT) positively impacts muscle morphology and performance in persons with Parkinson's disease (PD); however, optimal training frequencies for VBT in patients with PD remain undetermined.

A hop testing alternative for functional performance following anterior cruciate ligament reconstruction.

The purpose of this work was to provide a simple method to determine reactive strength during the 6-meter timed hop test (6mTH) and evaluate its association with isokinetic peak torque in patients following anterior cruciate ligament reconstruction (ACLR). Twenty-nine ACLR patients who were at least four months from surgery were included in this analysis. Participants were brought into the laboratory on one occasion to complete functional testing.

Velocity-Based Training Affects Function, Strength, and Power in Persons with Parkinson's Disease.

Calaway, CC, Martinez, KJ, Calzada Bichili, AR, Caplan, JH, Milgrim, WP, Mann, JB, Haq, I, and Signorile, JF. Velocity-based training affects function, strength, and power in persons with Parkinson's disease. J Strength Cond Res XX(X): 000-000, 2024-Velocity-based training (VBT) is commonly associated with high-level athletes.

Choriocapillaris Perfusion after 8 Weeks of High-Speed Circuit Training in Older Healthy Adults.

Purpose: The aim of this study was to examine the impact of an 8-week high-speed circuit resistance training program (HSCT) on choriocapillaris density (CCD) in healthy older adults.

Methods: Eighteen cognitively normal older adults were enrolled and randomly assigned to either the HSCT or the control group (CON). The HSCT group was comprised of 11 participants who trained three times a week for eight weeks, while the CON group consisted of 7 participants who did not engage in formal training.

The Impact of Velocity-Based Training on Load-Velocity Relationships in Leg Press and Chest Press for Older Persons.

Calaway, C, Mishra, S, Parrino, R, Martinez, KJ, Mann, JB, and Signorile, JF. Velocity-based training affects the load-velocity relationship in leg press and chest press for older persons. J Strength Cond Res 38(6): 1136-1143, 2024-This study examined the impact of 3 months of velocity-based training (VBT) on chest press (CP) and leg press (LP) maximal strength (1 repetition maximum [1RM]), peak power (PP), and percentage load where PP was achieved (%1RMPP) in older adults.

Decreased retinal capillary density as a beneficial response to 24-week high-speed circuit resistant training in healthy older adults.

Purpose: To determine the changes in retinal microvascular density after a 24-week high-speed circuit resistance training program (HSCT) in healthy older adults.

Methods: Thirty healthy older adults were recruited and randomly assigned to either a training group (HSCT) or a non-training (CON) group. Fifteen subjects (age 73.

Leg Press and Chest Press Power Normative Values by Half Decade in Older Women.

Parrino, RL, Martinez, KJ, Konlian, JA, Conti, JM, and Signorile, JF. Leg press and chest press power normative values by half decade in older women. J Strength Cond Res 38(5): 991-998, 2024-Neuromuscular power is essential for the performance of most activities of daily living and the maintenance of functional independence throughout the aging process.

Impact of Quadriceps Tendon Graft Thickness on Electromechanical Delay and Neuromuscular Performance After ACL Reconstruction.

Background: Both partial- and full-thickness quadriceps tendon (QT) graft harvests are used for anterior cruciate ligament reconstruction (ACLR).

Purpose: To evaluate the impact of QT graft harvest depth (full or partial thickness) on electromechanical delay (EMD), peak torque (PT), and rate of torque development (RTD) after ACLR.

Study Design: Controlled laboratory study.

A comparison of three-dimensional kinematics between markerless and marker-based motion capture in overground gait.

Vision-based methods using RGB inputs for human pose estimation have grown in recent years but have undergone limited testing in clinical and biomechanics research areas like gait analysis. The purpose of the present study was to compare lower extremity kinematics during overground gait between a traditional marker-based approach and a commercial multi-view markerless system in a sample of subjects including young adults, older adults, and adults diagnosed with Parkinson's disease. A convenience sample of 35 adults between the age of 18-85 years were included in this study, yielding a total of 114 trials and 228 gait cycles that were compared between systems.

Prediction of gait kinetics using Markerless-driven musculoskeletal modeling.

Video-based motion analysis systems are emerging in the biomechanics research community, yet there is limited exploration of kinetics prediction using RGB-markerless kinematics and musculoskeletal modeling. This project aimed to provide ground reaction force (GRF) and ground reaction moment (GRM) predictions during over-ground gait by introducing RGB-markerless kinematics into a musculoskeletal modeling framework. Full-body markerless kinematic inputs and musculoskeletal modeling were used to obtain GRF and GRM predictions which were compared to measured force plate values.

Validity of artificial intelligence-based markerless motion capture system for clinical gait analysis: Spatiotemporal results in healthy adults and adults with Parkinson's disease.

Markerless motion capture methods are continuously in development to target limitations encountered in marker-, sensor-, or depth-based systems. Previous evaluation of the KinaTrax markerless system was limited by differences in model definitions, gait event methods, and a homogenous subject sample. The purpose of this work was to evaluate the accuracy of spatiotemporal parameters in the markerless system with an updated markerless model, coordinate- and velocity-based gait events, and subjects representing young adult, older adult, and Parkinson's disease groups.

The Associations Between Quadriceps Tendon Graft Thickness and Isokinetic Performance.

Background: Anterior cruciate ligament reconstruction (ACLR) using the quadriceps tendon is an increasingly popular technique. Both partial-thickness quadriceps tendon (PT-Q) and full-thickness quadriceps tendon (FT-Q) graft depths are employed.

Hypothesis/purpose: This study was designed to assess isokinetic peak torque, average power, and total work during knee extension in patients with FT-Q or PT-Q grafts for ACLR.

Reliability of Gallon-Jug Shelf-Transfer Power Equations in Older Women.

Ly, A, Strand, KL, Courtney, KJ, Barry, SS, Liscano, JA, Trebotich, TL, Martin-Diala, C, Martin, E, and Signorile, JF. Reliability of gallon-jug shelf-transfer test power equations in older women. J Strength Cond Res 37(5): 1124-1130, 2023-This study examined the test-retest reliability of the gallon-jug shelf-transfer (GJST) test as a measure of upper-body functional power in older women.

Randomized Controlled Study of Self-Managed Music-Guided Exercise Intervention Following Intensive Care.

Background: Patients who are discharged from the intensive care unit (ICU; termed ICU survivors) often experience persistent physical impairment.

Objective: The aim of this study was to explore the effects of a self-managed, music-guided exercise intervention on physical outcomes and adherence rates among ICU survivors.

Methods: A randomized controlled design was used.

Concurrent validity of artificial intelligence-based markerless motion capture for over-ground gait analysis: A study of spatiotemporal parameters.

Gait analysis is used in research and clinical environments; yet several limitations exist in current methodologies. Markerless systems, utilizing high-speed video and artificial intelligence, eliminate most limitations encountered in marker-, depth-, or inertial sensor-based systems; however, further development is needed to improve their utility and accessibility in practice. Spatiotemporal parameters from 22 young adults were estimated during over-ground gait.

Improvement of Retinal Capillary Function After High-Speed Circuit Resistance Training in Healthy Older Adults.

Background: To determine the retinal capillary function (RCF, the efficiency of blood flow transferring in the capillary network) and its relation to cognitive function in healthy older people without known cognitive impairment following an 8-week high-speed circuit resistance training program (HSCT).

Methods: Eleven subjects in the HSCT group and 7 age-matched nontraining controls (CON) were recruited. The HSCT group trained 3 times per week for 8 weeks, whereas CON performed no formal training.

Validity and Reliability of the Seated Medicine Ball Throw as a Measure of Upper Body Power in Older Women.

Strand, KL, Ly, AS, Barry, SS, Liscano, JA, Trebotich, TL, Martin-Diala, C, Martin, E, and Signorile, JF. Validity and reliability of the seated medicine ball throw as a measure of upper body power in older women. J Strength Cond Res 37(4): 902-908, 2023-In women, aging is associated with diminishing upper body power, which may increase the risk of falls and fall-related injury; however, the validity and reliability of clinical tests to evaluate upper body power need to be confirmed.

Age-related focal thinning of the ganglion cell-inner plexiform layer in a healthy population.

Background: Given the aging of the population worldwide, to learn the underlying age-related biological phenomena is important to improve the understanding of the ageing process. Neurodegeneration is an age-associated progressive deterioration of the neuron. Retinal neurodegeneration during aging, such as the reduction in thickness of the retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) measured by optical coherence tomography (OCT), has been reported, but no studies have provided their specific alteration patterns with age.

Monitoring joint mechanics in anterior cruciate ligament reconstruction using depth sensor-driven musculoskeletal modeling and statistical parametric mapping.

The incidence of anterior cruciate ligament injury and reconstruction (ACLR) may set the stage for the development of early onset osteoarthritis in these patients. Development of accessible quantitative motion capture methodologies for recurrent monitoring of knee joint loading during daily activities following ACLR is necessary. This study aimed to compare lower extremity kinetics between ACLR affected limbs, ACLR unaffected limbs, and dominant limbs of healthy control subjects during over-ground gait and stair ascent using a single depth sensor-driven musculoskeletal modeling approach.