Gary Heise

• University of Northern Colorado

Individuals returning to sport after anterior cruciate ligament reconstruction (ACLR) are at an increased risk of sustaining a subsequent ACL injury. It is suspected that increased reliance on visual information to maintain stability may factor into this increased risk. The connection between visual reliance and ACLR is not well understood during d...

Background Persons with transtibial amputation report curb negotiation is more challenging than negotiating stairs. It is unknown if amputation technique influences curb negotiation ability. Traditional transtibial amputation surgical techniques do not join the distal tibia and fibula (non-Ertl), whereas a transtibial osteomyoplastic amputation (Er...

Background: Some comparisons between walking gait of obese and non-obese adults have been made during barefoot conditions, and others while shod. Methodological differences, footwear conditions, and gait speed disparities among the research done on overweight individuals were the factors motivating the present study. Research question: The present...

Presentation on the effects of exposure time and landing velocity on common dynamic stability assessment indices

Background: The combination of peripheral neuropathy and other treatment-associated side effects is likely related to an increased incidence of falls in cancer survivors. The purpose of this study was to quantify differences in postural stability between healthy age-matched controls and cancer survivors. Methods: Quiet standing under four condit...

Introduction: • Analysis of postural control attempts to gain insight into postural stability • Collins and DeLuca [1] proposed an analysis method which attempts to yield more physiologically meaningful results from a stabilogram • Stabilogram-diffusion analysis (SDA) models COP trajectories as a system of random walks • A critical point is defined...

Background: People with transtibial amputation stand ~50times/day. There are two general approaches to transtibial amputation: 1) distal tibia and fibula union using a "bone-bridge" (Ertl), 2) non-union of the tibia and fibula (Non-Ertl). The Ertl technique may improve functional outcomes by increasing the end-bearing ability of the residual limb....

Lower extremity joint moment magnitudes during swing are dependent on the inertial properties of the prosthesis and residual limb of individuals with transtibial amputation (TTA). Often, intact limb inertial properties (INTACT) are used for prosthetic limb values in an inverse dynamics model even though these values overestimate the amputated limb’...

Gait data are commonly presented as an average of many trials or as an average across participants. Discrete data points (e.g., maxima or minima) are identified and used as dependent variables in subsequent statistical analyses. However, the approach used for obtaining average data from multiple trials is inconsistent and unclear in the biomechanic...

The purpose of this study was two-fold: 1) demonstrate a technique that can be used to directly estimate the inertial properties of a below-knee prosthesis, and 2) contrast the effects of the proposed technique and that of using intact limb inertial properties on joint kinetic estimates during walking in unilateral, transtibial amputees. An oscilla...

Dynamic stability is often measured by time to stabilization (TTS), which is calculated from the dwindling fluctuations of ground reaction force (GRF) components over time. Common protocols of dynamic stability research have involved forward or vertical jumps, neglecting different jump-landing directions. Therefore, the purpose of the present inves...

The purpose of the study was to compare the kinematics of the barbell back squat between two footwear conditions and to evaluate the results with respect to recommendations put forth in the National Strength and Conditioning Association position statement for proper squat technique. Twenty-five subjects with 5 – 7 years of resistance training exper...

The aim of the study was to analyze the ML knee displacement and its influence on barbell tilt and rotation displacement from the back squat. Based on the weight distribution (WtD) test, 13 were in the equal WtD group and 14 were in the unequal WtD group. All subjects performed 75% of 1RM barbell back squat with reflective markers on selected locat...

The purpose of this study was to investigate the influence of weight distribution (WtD) asymmetry on the biomechanics of a barbell back squat. This study included 2 groups of trained individuals who were separated based on a WtD test (n = 14 in each group). They performed the barbell back squats with 2 resistance levels (60 and 75% of 1 repetition...

Recent attention given to the mechanical work of the lower extremity joints, the emerging importance of the stance phase of running, and the lack of consensus regarding the biomechanical correlates to economical running were primary justifications for this study. The purpose of this experiment was to identify the correlations between metabolic powe...

Relationships between an index of running economy (VO2 per distance) and the temporal electromyographic characteristics of leg muscles were quantified in female runners. Sixteen women performed a 30-min treadmill run at a speed designed to elicit a hard rating of perceived of exertion. Near the end of the run, oxygen uptake, video, and electromyogr...

The purpose of this study was to compare muscle activity, kinematic, and oxygen consumption characteristics between forward and reverse arm cranking. Twenty able-bodied men performed 5-min exercise bouts of forward and reverse arm cranking while electromyographic (EMG), kinematic, and oxygen consumption data were collected. EMG activity of biceps b...

Objective: To determine if the lower trapezius muscle responds to scapular retraction exercise in ranges of motion available to rotator cuff repair patients in the first two weeks following surgery. Study design Randomized repeated measures. Setting Biomechanics laboratory in a University setting. Participants Twelve healthy women and eight men fre...

The purpose of this study was to determine if handgrip position during arm cranking exercise influences the neuromuscular activity of muscles biceps brachii (BB), lateral head of triceps brachii (TB), middle deltoid (DT), infraspinatus (IS) and brachioradialis (BR). Fifteen participants cranked an arm ergometer using three different handgrip positi...

It was hypothesized that certain ground reaction force (GRF) variables are positively correlated with running economy (RE; the aerobic demand at a single speed of running). Excessive momentum changes, quantified by linear impulse measures, as well the free moment applied to the running surface could be considered potentially wasteful efforts in ter...

Previous research has shown that passive muscle stretching can diminish the peak force output of subsequent maximal isometric and concentric contractions. The purpose of the present study was twofold: 1. to establish if the deleterious effect of stretching on performance also exists for a skill that relies on the rate of force production for succes...

The purpose of this study was to determine how muscle activity and oxygen consumption are influenced by reverse pedaling (RP) compared to forward pedaling (FP). Seventeen physically active males performed FP and RP at an external workrate of 157 W (80 rpm) while EMG data were collected from five muscles: rectus femoris (RF), biceps femoris (BF), ga...

By applying a simple, linear mass-spring model to running, the normalized leg spring stiffness (Kleg), the normalized effective vertical stiffness (Kvert), and the mass-specific mechanical power output of the spring (Psp) were determined and correlated with aerobic demand. The purpose of the study was to determine whether leg spring characteristics...

The purpose of this investigation was to determine, for a planar, multijoint throwing skill, if the relative contributions of the components of the net joint moment (NJM) at the elbow and shoulder change after practice. Each participant (N = 7) performed 200 throwing trials equally distributed across 5 consecutive days. Each participant threw a 0.1...

Relationships between running economy (RE; submaximal VO(2) for a given running speed) and the temporal EMG characteristics of bi-articular leg muscles were quantified in a group of well-trained runners. Nine subjects completed three test sessions: a determination of maximal aerobic demand (VO(2)max); an accommodation session at the experimental sp...

The purpose of this investigation was to determine, for a planar multijoint throwing skill, if electromyographic (EMG) amplitudes of eccentric and concentric muscle activity for two agonist muscles (i.e. agonists for the concentric phase) changed over the course of practice. Eighteen men threw a weighted ball with their dominant arm at a target whi...

The interrelationships between aerobic demand, kinematic and kinetic-based estimates of mechanical power output and energy transfer, and total body angular impulse (summation of net joint moments integrated with respect to time over a stride) were quantified for walking at 1.69 m.s-1 and running at 3.35 m.s-1 to assess the ability of these various...

Archery instructors believe that force distribution (FD) between the hand and bow grip can have a considerable effect on arrow flight, but there is no empirical support for this speculation. This study examined FD on the bow grip in experienced archers and explored the possible relationships between FD, performance, and fatigue. FD was quantified f...

The purpose of this study was to determine if matched increases in the moment of inertia of the leg about the hip (Ihip) achieved via different loading configurations produced similar changes in the aerobic demand and mechanics of walking at 1.69 m/s. Economy and selected temporal and kinematic descriptors of walking mechanics were quantified for 1...

Thesis (M.S.)--Arizona State University, 1989. Includes bibliographical references (leaves [35]-39). "UO 91 154." Microfiche. s