Life Sciences Commons^™

Infants Born Preterm Exhibit Different Patterns Of Center-Of-Pressure Movement Than Infants Born At Full Term, Stacey C. Dusing, Anastasia Kyvelidou, Vicki S. Mercer, Nikolaos Stergiou

Journal Articles

Background: Infants born preterm are at risk for developmental impairments related to postural control.

Objective: The purpose of this study was to determine whether infants born preterm and infants born at full term differed in postural control at 1 to 3 weeks after term age.

Design: This study included 17 infants born preterm (mean gestational age=31.9 weeks, range=25.0–34.6) and 15 infants born at full term (mean gestational age=38.9 weeks, range=37.3–40.6). All infants were without diagnosed neurological or genetic conditions.

Measurement: Center-of-pressure (COP) data were recorded at 5 Hz while each infant was positioned supine on a pressure-sensitive mat …

Wii-Fit For Balance And Gait In Skilled Nursing Facility: A Retrospective Study, K. P. Padala, Nicholas Stergiou, M. A. Bissell, S. Davis, T. Malloy, J. Potter, W. J. Burke

Journal Articles

Background: Falls in elderly are a major public health problem. Poor balance and gait abnormalities are risk factors for falls. Exercise improves gait and balance in elderly. However, it is difficult to engage patients in exercise programs. Wii-Fit might bridge this gap by providing high level of engagement at an affordable price. Wii-Fit is a Nintendo game used for balance, yoga, aerobics, and strength training. It is a TV based self-directed activity. Virtual trainers talk the user through the activity and track progress while visual and auditory feedback improve engagement. Anecdotal reports suggest improvement in balance and social benefits with …

Reply (Letter To The Editor): “Gait Variability Is Altered In Patients With Peripheral Arterial Disease”, Iraklis Pipinos, Sara A. Myers, Jason Johanning, Nikolaos Stergiou

Journal Articles

No abstract provided.

The Effects Of Shoe Traction And Obstacle Height On Lower Extremity Coordination Dynamics During Walking, Leslie M. Decker, Jeremy J. Houser, John M. Noble, Gregory M. Karst, Nikolaos Stergiou

Journal Articles

This study aims to investigate the effects of shoe traction and obstacle height on lower extremity relative phase dynamics (analysis of intralimb coordination) during walking to better understand the mechanisms employed to avoid slippage following obstacle clearance. Ten participants walked at a self-selected pace during eight conditions: four obstacle heights (0%, 10%, 20%, and 40% of limb length) while wearing two pairs of shoes (low and high traction). A coordination analysis was used and phasing relationships between lower extremity segments were examined. The results demonstrated that significant behavioral changes were elicited under varied obstacle heights and frictional conditions. Both decreasing …

Effect Of Femoral Tunnel Placement For Reconstruction Of The Anterior Cruciate Ligament On Tibial Rotation, Stavros Ristanis, Nikolaos Stergiou, Eleftheria Siarava, Aikaterini Ntoulia, Grigoris Mitsionis, Anastasios D. Georgoulis

Journal Articles

Background: Rotational knee movement after reconstruction of the anterior cruciate ligament has been difficult to quantify. The purpose of this study was to identify in vivo whether a more horizontal placement of the femoral tunnel (in the ten o'clock position rather than in the eleven o'clock position) can restore rotational kinematics, during highly demanding dynamic activities, in a knee in which a bone-patellar tendon-bone graft had been used to reconstruct the anterior cruciate ligament.

Methods: We evaluated ten patients in whom a bone-patellar tendon-bone graft had been used to reconstruct the anterior cruciate ligament with the femoral tunnel in the …

Electromechanical Delay Of The Knee Flexor Muscles Is Impaired After Harvesting Hamstring Tendons For Anterior Cruciate Ligament Reconstruction, Stavros Ristanis, Elias Tsepis, Dimitrios Giotis, Nicholas Stergiou, Guiliano Cerulli, Anastasios D. Georgoulis

Journal Articles

Background

Changes in electromechanical delay during muscle activation are expected when there are substantial alterations in the structural properties of the musculotendinous tissue. In anterior cruciate ligament reconstruction, specific tendons are being harvested for grafts. Thus, there is an associated scar tissue development at the tendon that may affect the corresponding electromechanical delay.

Purpose

This study was conducted to investigate whether harvesting of semitendinosus and gracilis tendons for anterior cruciate ligament reconstruction will affect the electromechanical delay of the knee flexors.

Study Design

Case-control study; Level of evidence, 3.

Methods

The authors evaluated 12 patients with anterior cruciate ligament reconstruction …

Use Of Information Entropy Measures Of Sitting Postural Sway To Quantify Developmental Delay In Infants, Joan E. Deffeyes, Regina T. Harbourne, Stacey L. Dejong, Anastasia Kyvelidou, Wayne A. Stuberg, Nikolaos Stergiou

Journal Articles

Background: By quantifying the information entropy of postural sway data, the complexity of the postural movement of different populations can be assessed, giving insight into pathologic motor control functioning.

Methods: In this study, developmental delay of motor control function in infants was assessed by analysis of sitting postural sway data acquired from force plate center of pressure measurements. Two types of entropy measures were used: symbolic entropy, including a new asymmetric symbolic entropy measure, and approximate entropy, a more widely used entropy measure. For each method of analysis, parameters were adjusted to optimize the separation of the results from the …

Nonlinear Analysis Of Sitting Postural Sway Indicates Developmental Delay In Infants, Joan E. Deffeyes, Regina T. Harbourne, Anastasia Kyvelidou, Wayne A. Stuberg, Nikolaos Stergiou

Journal Articles

Background

Upright sitting is one of the first developmental motor milestones achieved by infants, and sitting postural sway provides a window into the developing motor control system. A variety of posture sway measures can be used, but the optimal measures for infant development have not been identified.

Methods

We have collected sitting postural sway data from two groups of infants, one with typical development (n = 33), and one with delayed development and either diagnosed with or at risk for cerebral palsy (n = 26), when the infants had developed to the point where they could just maintain …

High Intensity Running Results In An Impaired Neuromuscular Response In Acl Reconstructed Individuals, Kostas Patras, Giorgos Ziogas, Stavros Ristanis, Elias Tsepis, Nikolaos Stergiou, Anastasios D. Georgoulis

Journal Articles

Anterior cruciate ligament (ACL) reconstruction reestablishes electromyographic activity during moderate activities such as walking but is unclear if this is also the case in sports activities such as high intensity running that results in accumulation of metabolic fatigue. Nine bone-patella tendon-bone ACL reconstructed athletes were evaluated 19.2 (5.7) months post-operatively using a telemetric electromyographic system. The neuromuscular response of vastus lateralis and biceps femoris muscles was tested bilaterally on separate occasions during 10 min running at moderate intensity (20% below the lactate threshold) and 10 min running at high intensity (40% above the lactate threshold). During moderate intensity running, electromyographic …

Reliability Of Center Of Pressure Measures For Assessing The Development Of Sitting Postural Control, Anastasia Kyvelidou, Regina T. Harbourne, Wayne A. Stuberg, Junfeng Sun, Nikolaos Stergiou

Journal Articles

Objectives: To determine the reliability of linear and nonlinear tools, including intrasession and intersession reliability, when used to analyze the center of pressure (COP) time series during the development of infant sitting postural control.

Design: Longitudinal study.

Setting: University hospital laboratory.

Participants: Typically developing infants (N33; mean SD age at entry in the study, 152.417.6d).

Interventions: Not applicable.

Main Outcome Measures: Infants were tested twice in 1 week at each of the 4 months of the study. Sitting COP data were recorded for 3 trials at each session (2 each month within 1 week). …

The Effect Of Anterior Cruciate Ligament Reconstruction On Stride-To-Stride Variability, Constantina O. Moraiti, Nikolaos Stergiou, Stavros Ristanis, Haris S. Vasiliadis, Kostas Patras, Cassandra Lee, Anastasios D. Georgoulis

Journal Articles

Purpose: The purpose of our study was to investigate the functional outcome after anterior cruciate ligament (ACL) reconstruction using bone–patellar tendon– bone (BPTB) and quadrupled semitendinosus and gracilis tendon (ST/G) autografts by evaluating stride-to-stride variability.

Methods: Six patients with BPTB and 6 patients with STG ACL reconstruction, 2 years postoperatively, and 6 healthy control subjects walked on a treadmill at a self-selected pace while 2 minutes of continuous kinematic data were recorded with a 6-camera optoelectronic system. Stride-to-stride variability was calculated from the knee flexion/extension data using the nonlinear measure of approximate entropy, which estimates the regularity of movement patterns …

Physiological Demands Of Competitive Basketball, Kenji Narazaki, Kris E. Berg, Nikolaos Stergiou, Bing Chen

Journal Articles

The aim of this study was to assess physiological demands of competitive basketball by measuring oxygen consumption (VO₂) and other variables during practice games. Each of 12 players (20.4 ± 1.1 years) was monitored in a 20-min practice game, which was conducted in the same way as actual games with the presence of referees and coaches. VO₂ was measured by a portable system during the game and blood lactate concentration (LA) was measured in brief breaks. Subjects were also videotaped for time-motion analysis. Female and male players demonstrated respective VO₂ of 33.4 ± 4.0 and 36.9 …

Gait Variability Is Altered In Patients With Peripheral Arterial Disease, Sara A. Myers, Jason Johanning, Nikolaos Stergiou, Ronaldo Celis, Leon Robinson

Journal Articles

Objective

Claudication is the most common presentation of peripheral arterial disease (PAD), producing significant ambulatory compromise. Claudicating patients, most of whom are elderly, have reduced mobility and poor health outcomes, including an increased risk of falls. The gait of elderly fallers is characterized by increased variability. Increase in the variability of the locomotor system makes the gait more noisy and unstable. The purpose of this study is to investigate gait variability in patients with PAD.

Methods

Nineteen symptomatic PAD patients (age, 63.6 ± 9.8 years; body mass, 82.1 ± 18.5 kg; height, 1.71 ± 0.06 m) walked on a treadmill …

Factors Affecting Functional Reach Scores In Youth With Typical Development, Kathleen G. Volkman, Nikolaos Stergiou, Wayne A. Stuberg, Regina T. Harbourne, Daniel Blanke, Julie Stoner

Journal Articles

Purpose: Functional Reach Test scores were examined for the effects of traditional and alternate methods and subject characteristics.

Methods: Eighty subjects aged 7 to 16 years were tested. Effects of measurement method (from finger-to-finger or from toe-to-finger) and style of reach (1 or 2 arms) were investigated. Five subject variables were analyzed for interactions among the methods and groups defined by subject characteristics.

Results: Measurement method and style of reach showed a significant interaction. Interaction of method with subject characteristics was significant for age, height, and base of support only. Height groups by quartile were significantly different and scores increased …

Objective Evaluation Of Expert And Novice Performance During Robotic Surgical Training Tasks, Timothy N. Judkins, D. Oleynikov, Nikolaos Stergiou

Journal Articles

Background - Robotic laparoscopic surgery has revolutionized minimally invasive surgery for the treatment of abdominal pathologies. However, current training techniques rely on subjective evaluation. The authors sought to identify objective measures of robotic surgical performance by comparing novices and experts during three training tasks.

Methods - Five novices (medical students) were trained in three tasks with the da Vinci Surgical System. Five experts trained in advanced laparoscopy also performed the three tasks. Time to task completion (TTC), total distance traveled (D), speed (S), curvature (Ƙ), and relative phase (Φ) were measured.

Results - Before training, TTC, D, and …

Movement Variability And The Use Of Nonlinear Tools: Principles To Guide Physical Therapist Practice, Regina T. Harbourne, Nikolaos Stergiou

Journal Articles

Fields studying movement generation, including robotics, psychology, cognitive science and neuroscience utilize concepts and tools related to the pervasiveness of variability in biological systems. The concepts of variability and complexity, and the nonlinear tools used to measure these concepts open new vistas for physical therapy practice and research in movement dysfunction of all types. Because mounting evidence supports the necessity of variability for health and functional movement, we argue in this perspective for changes in the way therapists view variability both in theory and in action. By providing clinical examples, as well as applying existing knowledge about complex systems, we …

Anterior Cruciate Ligament Reconstruction With A Quadrupled Hamstrings Tendon Autograft Does Not Restore Tibial Rotation To Normative Levels During Landing From A Jump And Subsequent Pivoting, Vasilis Chouliaras, Stavros Ristanis, Constantina O. Moraiti, V. Tzimas, Nicholas Stergiou, Anastasios D. Georgoulis

Journal Articles

Aim. Recent research suggested that the anterior curciate ligament (ACL) reconstruction does not restore tibial rotation to normal levels when a bone patellar tendon bone (BPTB) graft is used during high demanding activities. Our goal was to determine if the usage of an alternative graft, as the quadrupled semitendinosus-gracilis (ST/G), restore tibial rotation to normal values in a population of athletically active individuals while performing a usual for their sport activity.

Methods. Eleven subjects, all reconstructed with an ST/G graft, were assessed in vivo, 9 months postoperatively, while they jumped off a 40 cm platform, landed on the ground and …

Electromyographic Response Is Altered During Robotic Surgical Training With Augmented Feedback, Timothy N. Judkins, D. Oleynikov, Nikolaos Stergiou

Journal Articles

There is a growing prevalence of robotic systems for surgical laparoscopy. We previously developed quantitative measures to assess robotic surgical proficiency, and used augmented feedback to enhance training to reduce applied grip force and increase speed. However, there is also a need to understand the physiological demands of the surgeon during robotic surgery, and if training can reduce these demands. Therefore, the goal of this study was to use clinical biomechanical techniques via electromyography (EMG) to investigate the effects of real-time augmented visual feedback during short-term training on muscular activation and fatigue. Twenty novices were trained in three inanimate surgical …

Nebraska Biomechanics Core Facilty 2008 Annual Report, Issue 7, Nebraska Biomechanics Core Facility

Biomechanics Annual Report

April 2008 - March 2009

This issue features Announcements, Featured News, Nonlinear Workshop, Projects, Collaborations, Visitors, Awards, Publications, and Support.

Peripheral Arterial Disease Affects Kinematics During Walking, Ronaldo Celis, Iraklis Pipinos, Melissa Scott-Pandorf, Sara A. Myers, Nikolaos Stergiou, Jason Johanning

Journal Articles

Objective: Claudication is the most common manifestation of peripheral arterial disease (PAD) producing significant ambulatory compromise. The purpose of this study was to use advanced biomechanical analysis to characterize the kinematic ambulatory pattern of claudicating patients. We hypothesized that compared with control subjects, claudicating patients have altered kinematic gait patterns that can be fully characterized utilizing advanced biomechanical analysis.

Methods: The study examined fourteen PAD patients (age: 58 ± 3.4 years; weight: 80.99 ± 15.64 kg) with clinically diagnosed femoro-popliteal occlusive disease (Ankle Brachial Index (ABI): 0.56 ± 0.03, range 0.45 to 0.65) and five healthy controls (age: 53 ± …

The Effects Of A Plyometric Training Program On The Latency Time Of The Quadriceps Femoris And Gastrocnemius Short-Latency Responses, D. H. Potach, Dimitrios Kastavelis, Gregory M. Karst, R. W. Latin, Nikolaos Stergiou

Journal Articles

Aim: The purpose of this study was to determine if a plyometric training program can affect the latency time of the quadriceps femoris and gastrocnemius short-latency responses (SLRs) of the stretch reflex.

Methods: Sixteen healthy subjects (12 female and 4 male) were randomly assigned to either a control or a plyometric training group. Maximum vertical jump height (VJ) and SLRs of both quadriceps femoris and gastrocnemius were measured before and after a four week plyometric training program.

Results: Plyometric training significantly increased VJ (mean+/-SEM) by 2.38+/-0.45 cm (P<0.05) and non-significantly decreased the latency time of the quadriceps femoris SLR (mean+/-SEM) 0.363+/-0.404 ms (P>0.05) and gastrocnemius SLR (mean+/-SEM) 0.392+/-0.257 ms (P>0.05). VJ results …

Development Of Upper Body Coordination During Sitting In Typically Developing Infants, Anastasia Kyvelidou, Wayne A. Stuberg, Regina T. Harbourne, Joan E. Deffeyes, Daniel Blanke, Nikolaos Stergiou

Journal Articles

Our goal was to determine how the actions of the thorax and the pelvis are organized and coordinated to achieve independent sitting posture in typically developing infants. The participants were 10 typically developing infants who were evaluated longitudinally from first onset of sitting until sitting independence. Each infant underwent nine testing sessions. The first session included motor evaluation with the Peabody test. The other eight sessions occurred over a period of 4 mo where sitting behavior was evaluated by angular kinematics of the thorax and the pelvis. A physical therapist evaluated sitting behavior in each session and categorized it according …