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Faculty Publications - College of Physical Therapy

Biomechanics

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Full-Text Articles in Physical Therapy

Midfoot Power During Walking And Stair Ascent In Healthy Adults, Frank Diliberto, Jeff Houck Jan 2018

Midfoot Power During Walking And Stair Ascent In Healthy Adults, Frank Diliberto, Jeff Houck

Faculty Publications - College of Physical Therapy

Introduction/Purpose: Intrinsic foot muscles have the capacity to attenuate and reverse arch deformation under loaded conditions. This function is proposed to be an important component in generating the midfoot power and stability requisite for gastroc-soleus muscle action at the ankle during forward propulsion. Synergistic activation of intrinsic foot muscles is proposed to function as a ‘foot core’ during weightbearing activity that is analogous to the function of the smaller muscles at the spine. If this theory were sound, midfoot power would be expected to increase, potentially in proportion to ankle power, as the muscular demand of a task increases. The …


Influence Of Upper Extremity Assistance On Lower Extremity Force Application Symmetry In Individuals Post–Hip Fracture During The Sit-To-Stand Task, Janet A. Kneiss, Jeff R. Houck, Susan A. Bukata, J. Edward Puzas May 2012

Influence Of Upper Extremity Assistance On Lower Extremity Force Application Symmetry In Individuals Post–Hip Fracture During The Sit-To-Stand Task, Janet A. Kneiss, Jeff R. Houck, Susan A. Bukata, J. Edward Puzas

Faculty Publications - College of Physical Therapy

STUDY DESIGN: Controlled laboratory study using a cross-sectional design.

OBJECTIVES: To compare lower extremity force applications during a sit-to-stand (STS) task with and without upper extremity assistance in older individuals post–hip fracture to those of age matched controls.

BACKGROUND: A recent study documented the dependence on upper extremity assistance and the uninvolved lower limb during an STS task in individuals post–hip fracture. This study extends this work by examining the effect of upper extremity assistance on symmetry of lower extremity force applications.

METHODS: Twenty-eight community-dwelling elderly subjects, 14 who had recovered from a hip fracture and 14 controls, participated in …


Analysis Of Vertical Ground Reaction Force Variables During A Sit To Stand Task In Participants Recovering From A Hip Fracture, Jeff R. Houck, Janet Kneiss, Susan V. Bukata, J. Edward Puzas Jun 2011

Analysis Of Vertical Ground Reaction Force Variables During A Sit To Stand Task In Participants Recovering From A Hip Fracture, Jeff R. Houck, Janet Kneiss, Susan V. Bukata, J. Edward Puzas

Faculty Publications - College of Physical Therapy

Background: A Sit to Stand task following a hip fracture may be achieved through compensations (e.g. bilateral arms and uninvolved lower extremity), not restoration of movement strategies of the involved lower extremity. The primary purpose was to compare upper and lower extremity movement strategies using the vertical ground reaction force during a Sit to Stand task in participants recovering from a hip fracture to control participants. The secondary purpose was to evaluate the correlation between vertical ground reaction force variables and validated functional measures.

Methods: Twenty eight community dwelling older adults, 14 who had a hip fracture and 14 control …


Deep Posterior Compartment Strength And Foot Kinematics In Subjects With Stage Ii Posterior Tibial Tendon Dysfunction, Christopher Neville, Adolph S. Flemister, Jeff Houck Jan 2010

Deep Posterior Compartment Strength And Foot Kinematics In Subjects With Stage Ii Posterior Tibial Tendon Dysfunction, Christopher Neville, Adolph S. Flemister, Jeff Houck

Faculty Publications - College of Physical Therapy

Background: Tibialis posterior muscle weakness has been documented in subjects with Stage II posterior tibial tendon dysfunction (PTTD) but the effect of weakness on foot structure remains unclear. The association between strength and flatfoot kinematics may guide treatment such as the use of strengthening programs targeting the tibialis posterior muscle.

Materials and Methods: Thirty Stage II PTTD subjects (age; 58.1 ± 10.5 years, BMI 30.6 ± 5.4) and 15 matched controls (age; 56.5 ± 7.7 years, BMI 30.6 ± 3.6) volunteered for this study. Deep Posterior Compartment strength was measured from both legs of each subject and the strength ratio …


Effects Of The Airlift Pttd Brace On Foot Kinematics In Subjects With Stage Ii Posterior Tibial Tendon Dysfunction, Christopher Neville, A. Samuel Flemister, Jeff Houck Jan 2009

Effects Of The Airlift Pttd Brace On Foot Kinematics In Subjects With Stage Ii Posterior Tibial Tendon Dysfunction, Christopher Neville, A. Samuel Flemister, Jeff Houck

Faculty Publications - College of Physical Therapy

Study Design: Experimental laboratory study.

Objectives: To investigate the effect of inflation of the air bladder component of the AirLift PTTD brace on relative foot kinematics in subjects with stage II posterior tibial tendon dysfunction (PTTD).

Background: Orthotic devices are commonly recommended in the conservative management of stage II PTTD to improve foot kinematics.

Methods and Measures: Ten female subjects with stage II PTTD walked in the laboratory wearing the AirLift PTTD brace during 3 testing conditions (air bladder inflation to 0, 4, and 7 PSI [SI equivalent: 0, 27 579, and 48 263 Pa]). Kinematics were recorded from the …


Choosing Among 3 Ankle-Foot Orthoses For A Patient With Stage Ii Posterior Tibial Tendon Dysfunction, Christopher Neville, Jeff Houck Jan 2009

Choosing Among 3 Ankle-Foot Orthoses For A Patient With Stage Ii Posterior Tibial Tendon Dysfunction, Christopher Neville, Jeff Houck

Faculty Publications - College of Physical Therapy

No head-to-head comparisons of different orthoses for patients with stage II posterior tibial tendon dysfunction (PTTD) have been performed to date. Additionally, the cost of orthoses varies considerably, thus choosing an effective orthosis that is affordable to the patient is largely a trial-and-error process. Case Description: A 77-year-old woman was seen with complaints of abnormal foot posture (“my foot is out”), minimal medial foot and ankle pain, and a 3-year history of conservatively managed stage II PTTD. The patient was not able to complete 1 single-limb heel rise on the involved side, while she could complete 3 on the uninvolved …


Comparison Of Frontal Plane Trunk Kinematics And Hip And Knee Moments During Anticipated And Unanticipated Walking And Side Step Cutting Tasks, Jeff R. Houck, Andrew Duncan, Kenneth E. De Haven Nov 2006

Comparison Of Frontal Plane Trunk Kinematics And Hip And Knee Moments During Anticipated And Unanticipated Walking And Side Step Cutting Tasks, Jeff R. Houck, Andrew Duncan, Kenneth E. De Haven

Faculty Publications - College of Physical Therapy

Background: Frontal plane trunk and lower extremity adjustments during unanticipated tasks are hypothesized to influence hip and knee neuromuscular control, and therefore, contribute to anterior cruciate ligament (ACL) injury risk. The aims of this study were to examine frontal plane trunk/hip kinematics and hip and knee moments (measures of neuromuscular control) during unanticipated straight and side step cut tasks.

Methods: Kinematic and kinetic variables were collected while subjects performed two anticipated tasks, including walking straight (ST) and side step cutting (SS), and two unanticipated tasks (STU and SSU). Foot placement, thorax–pelvis–hip kinematic variables and hip and knee moments were calculated …


Knee And Hip Angle And Moment Adaptations During Cutting Tasks In Subjects With Anterior Cruciate Ligament Deficiency Classified As Noncopers, Jeff R. Houck, Andrew Duncan, Kenneth E. De Haven Aug 2005

Knee And Hip Angle And Moment Adaptations During Cutting Tasks In Subjects With Anterior Cruciate Ligament Deficiency Classified As Noncopers, Jeff R. Houck, Andrew Duncan, Kenneth E. De Haven

Faculty Publications - College of Physical Therapy

Study Design: Two-factor mixed-design study, with factors including group (control and noncoper) and task (sidestep, crossover, and straight).

Objectives: To compare the knee and hip joint angles and moments of control subjects and subjects with an anterior cruciate ligament (ACL) deficient knee classified as noncopers, during a sidestep, crossover, and straight-ahead task.

Background: Subjects with ACL deficiency primarily note difficulty with cutting tasks as opposed to straight-ahead tasks. Yet, previous studies have primarily focused on straight-ahead tasks.

Methods and Measures: Fifteen subjects with ACL deficiency classified as noncopers, based on the number of giving-way episodes (1) and global question of …


In-Season Functional Shoulder Training For High School Baseball Pitchers, Jason Brumitt, Erik Meira, Greg Davidson Feb 2005

In-Season Functional Shoulder Training For High School Baseball Pitchers, Jason Brumitt, Erik Meira, Greg Davidson

Faculty Publications - College of Physical Therapy

The overhead throwing motion is used in numerous sports including track, football, and baseball. Among these sports, the baseball pitch is unique in the demands placed upon the shoulder. The forces created in the shoulder can potentially lead to pathology affecting the athlete's career. To enhance performance and decrease the risk of injury, it is important that the athlete participate in a year-round periodized program. Inappropriate or deficient training combined with the stress that the shoulder experiences during a season can lead to strains, impingement, tendon or labral tears, and instabilities.


Rabbit Knee Joint Biomechanics: Motion Analysis And Modeling Of Forces During Hopping, David L. Gushue, Jeff Houck, Amy L. Lerner Jan 2005

Rabbit Knee Joint Biomechanics: Motion Analysis And Modeling Of Forces During Hopping, David L. Gushue, Jeff Houck, Amy L. Lerner

Faculty Publications - College of Physical Therapy

Although the rabbit hindlimb has been commonly used as an experimental animal model for studies of osteoarthritis, bone growth and fracture healing, the in vivo biomechanics of the rabbit knee joint have not been quantified. The purpose of this study was to investigate the kinematic and kinetic patterns during hopping of the adult rabbit, and to develop a model to estimate the joint contact force distribution between the tibial plateaus. Force platform data and three-dimensional motion analysis using infrared markers mounted on intracortical bone pins were combined to calculate the knee and ankle joint intersegmental forces and moments. A statically …


Associations Of Knee Angles, Moments And Function Among Subjects That Are Healthy And Anterior Cruciate Ligament Deficient (Acld) During Straight Ahead And Crossover Cutting Activities, Jeff Houck, H. John Yack Jan 2003

Associations Of Knee Angles, Moments And Function Among Subjects That Are Healthy And Anterior Cruciate Ligament Deficient (Acld) During Straight Ahead And Crossover Cutting Activities, Jeff Houck, H. John Yack

Faculty Publications - College of Physical Therapy

The objective of this study was to compare knee angles and moments of healthy subjects (n/20) and subjects that were anterior cruciate ligament deficient (ACLD) (n/16) during stepping and crossover cutting activities. Subjects that were ACLD were separated into high (n/7) and low (n/9) functioning groups based on knee functioning ratings. Knee angles and moments were estimated using three dimensional motion tracking and force plate data. The results suggest that knee angle and moment data were associated with level of functioning of ACLD subjects. Primarily knee frontal and transverse plane moments distinguished the stepping and crossover cut activities. Only some …


Self-Reported Giving-Way Episode During A Stepping-Down Task: Case Report Of A Subject With An Acl-Deficient Knee, Jeff Houck, Amy Lerner, David Gushue, H. John Yack Jan 2003

Self-Reported Giving-Way Episode During A Stepping-Down Task: Case Report Of A Subject With An Acl-Deficient Knee, Jeff Houck, Amy Lerner, David Gushue, H. John Yack

Faculty Publications - College of Physical Therapy

Study Design: Case report.

Objective: To describe the knee kinematics and moments of a giving-way trial of a subject with an anterior-cruciate-ligament– (ACL) deficient knee relative to his non–giving-way trials and to healthy subjects during a step-down task.

Background: Episodes of giving way are believed to damage joint structures, therefore treatments aim to prevent giving-way episodes, yet few studies document giving-way events.

Methods: The giving-way trial experienced by a 32-year-old male subject with ACL deficiency during a step-down task was compared to his non–giving-way trials (n = 5) and data from healthy subjects (n = 20). Position data collected at …