Engineering Commons^™

Balance Assessment Using A Smartwatch Inertial Measurement Unit With Principal Component Analysis For Anatomical Calibration, Benjamin M. Presley, Jeffrey C. Sklar, Scott J. Hazelwood, Britta Berg-Johansen, Stephen M. Klisch

Biomedical Engineering

Balance assessment, or posturography, tracks and prevents health complications for a variety of groups with balance impairment, including the elderly population and patients with traumatic brain injury. Wearables can revolutionize state-of-the-art posturography methods, which have recently shifted focus to clinical validation of strictly positioned inertial measurement units (IMUs) as replacements for force-plate systems. Yet, modern anatomical calibration (i.e., sensor-to-segment alignment) methods have not been utilized in inertial-based posturography studies. Functional calibration methods can replace the need for strict placement of inertial measurement units, which may be tedious or confusing for certain users. In this study, balance-related metrics from a smartwatch …

Baseball Pitching Arm Three-Dimensional Inertial Parameter Calculations From Body Composition Imaging And A Novel Overweight Measure For Youth Pitching Arm Kinetics, Dalton J. Jennings, Scott K. Reaves, Jeffrey Sklar, Colin Brown, John Mcphee, Scott Hazelwood, Stephen M. Klisch

Biomedical Engineering

Many baseball pitching studies have used inverse dynamics to assess throwing arm kinetics as high and repetitive kinetics are thought to be linked to pitching injuries. However, prior studies have not used participant-specific body segment inertial parameters (BSIPs), which are thought to improve analysis of high-acceleration motions and overweight participants. This study's objectives were to (1) calculate participant-specific BSIPs using dual energy X-ray absorptiometry (DXA) measures, (2) compare inverse dynamic calculations of kinetics determined by DXA-calculated BSIPs (full DXA-driven inverse dynamics) against kinetics using the standard inverse dynamics approach with scaled BSIPs (scaled inverse dynamics), and (3) examine associations between …

Effects Of Game Pitch Count And Body Mass Index On Pitching Biomechanics In 9-To 10-Year-Old Baseball Athletes, Jim D. Darke, Eshan M. Dandekar, Arnel L. Aguinaldo, Scott J. Hazelwood, Stephen M. Klisch

Biomedical Engineering

Background: Pitching while fatigued and body composition may increase the injury risk in youth and adult pitchers. However, the relationships between game pitch count, biomechanics, and body composition have not been reported for a study group restricted to 9-to 10-year-old athletes.

Hypothesis: During a simulated game with 9-to 10-year-old athletes, (1) participants will experience biomechanical signs of fatigue, and (2) shoulder and elbow kinetics will correlate with body mass index (BMI).

Study Design: Descriptive laboratory study. Methods: Thirteen 9-to 10-year-old youth baseball players pitched a simulated game (75 pitches). Range of motion and muscular output tests were conducted before and …

Effects Of Game Pitch Count And Body Mass Index On Pitching Biomechanics In 9- To 10-Year-Old Baseball Athletes, Scott Hazelwood, Jim D. Darke, Eshan M. Dandekar, Arnel L. Aguinaldo, Stephen M. Klisch

Biomedical Engineering

Background:

Pitching while fatigued and body composition may increase the injury risk in youth and adult pitchers. However, the relationships between game pitch count, biomechanics, and body composition have not been reported for a study group restricted to 9- to 10-year-old athletes.

Hypothesis:

During a simulated game with 9- to 10-year-old athletes, (1) participants will experience biomechanical signs of fatigue, and (2) shoulder and elbow kinetics will correlate with body mass index (BMI).

Study Design:

Descriptive laboratory study.

Methods:

Thirteen 9- to 10-year-old youth baseball players pitched a simulated game (75 pitches). Range of motion and …

Locked Plate Fixation Of Osteoporotic Humeral Shaft Fractures: Are Two Locking Screws Per Segment Enough?, David J. Hak, Peter Althausen, S J. Hazelwood

Biomedical Engineering

Objective: The purpose of this study was to compare the biomechanical behavior of using two versus three locking screws per bone segment in a cadaveric humerus fracture gap model.

Methods: Six matched pairs of elderly osteoporotic fresh–frozen human cadaveric humerii were used. An eight-hole locking compression plate was placed posteriorly on the humeral shaft and secured with either four or six bicortical locking screws. A 5-mm middiaphyseal gap osteotomy was created to simulate a comminuted fracture without bony contact. Specimens were tested in offset axial compression, four-point anteroposterior bending, four-point medial– lateral bending, and torsion. After the initial testing in …

Articular Cartilage Mechanical And Biochemical Property Relations Before And After In Vitro Growth, Timothy Ficklin, Gregory Thomas, James C. Barthel, Anna Asanbaeva, Eugene J. Thonar, Koichi Masuda, Albert C. Chen, Robert L. Sah, Andrew Davol, Stephen M. Klisch

Mechanical Engineering

The aim of this study was to design in vitro growth protocols that can comprehensively quantify articular cartilage structure–function relations via measurement of mechanical and biochemical properties. Newborn bovine patellofemoral groove articular cartilage explants were tested sequentially in confined compression (CC), unconfined compression (UCC), and torsional shear before (D0, i.e. day zero) and after (D14, i.e. day 14) unstimulated in vitro growth. The contents of collagen (COL), collagen-specific pyridinoline (PYR) crosslinks, glycosaminoglycan, and DNA significantly decreased during in vitro growth; consequently, a wide range of biochemical properties existed for investigating structure–function relations when pooling the D0 and D14 groups. All …

The Use Of Hinged External Fixation To Provide Additional Stabilization For Fractures Of The Distal Humerus, Christopher R. Deuel, Philip Wolinsky, Eric Shepherd, Scott Hazelwood

Biomedical Engineering

Objective: To assess improvements in fixation stability when a hinged unilateral external fixator is used to supplement compromised internal fixation for distal humerus fractures.

Methods: Removing a 1-cm section of the distal humerus in cadaveric whole-arm specimens created a comminuted distal humerus fracture model (AO type 13-A3). Fixation was then performed using different constructs representing optimal, compromised, or supplemented internal fixation. Internal fixation consisted of either 2 reconstruction plates with 1, 2, or 3 (optimal) distal attachment screws, or crossing medial and lateral cortical screws. A hinged external fixator was applied in combination with compromised internal fixation. The stability of …

The Biomechanical Aspects Of Pedestrian Protection, Krishnakanth Aekbote, Peter Schuster, Sunny Kankanala, Srini Sundararajan, Stephen W. Rouhana

Mechanical Engineering

In this paper a biomechanical basis for pedestrian protection is presented based on reviews of epidemiological and biomechanical studies conducted over the last three decades. Epidemiological studies reveal the nature and cause of pedestrian crashes and injuries sustained in the field. The various factors that influence pedestrian crashes and fatalities such as pedestrian demographics, time and location of crash, type of vehicles involved and their design characteristics, impact speeds, and nature and severity of injuries sustained are covered in the epidemiology section. The biomechanical studies identify the injury mechanisms and the biomechanical tolerances. Several biomechanical studies that attempt to identify …

A Theory Of Volumetric Growth For Compressible Elastic Biological Materials, Stephen M. Klisch, Timothy J. Van Dyke, Anne Hoger

Mechanical Engineering

A general theory of volumetric growth for compressible elastic materials is presented. The authors derive a complete set of governing equations in the present configuration for an elastic material undergoing a continuous growth process. In particular, they obtain two constitutive restrictions from a work-energy principle. First, the authors show that a growing elastic material behaves as a Green-elastic material. Second, they obtain an expression that relates the stress power due to growth to the rate of energy change due to growth. Then, the governing equations for a small increment of growth are derived from the more general theory. The equations …