Physical Therapy Commons^™

The Correlation Between Ankle Proprioception And Lower Extremity Muscle Reactions In Response To Simulated Ankle Sprains, Erin Carroll, Justin Stanek, Abby Salvadore

Clinical Practice in Athletic Training

Context: Neurological structures of the somatosensory system provide proprioceptive and neuromuscular input regarding joint positioning to the brain. Lower extremity motor control relies on local proprioceptive input to the central nervous system and neuromuscular control of individual joints to produce coordinated, global responses to external events. The purpose of this study was to investigate the relationship between ankle proprioception and lower extremity muscle reaction time in response to an unexpected ankle inversion perturbation.

Methods: Twenty healthy college-aged volunteers were recruited to participate by word of mouth. Absolute and exact errors for passive joint position sense (PJPS) were assessed using a …

Reduced Lower Extremity Strength, Altered Muscle Activation, And Unchanged Kinetics During Single-Leg Squatting In Males With Patellofemoral Pain Versus Pain-Free Males: A Cross-Sectional Analysis, Lisa T. Hoglund, Amy H. Amabile, Thomas Alexander Hulcher, Victoria K. Polansky, Erin L. Dopke

Department of Physical Therapy Faculty Papers

BACKGROUND: Patellofemoral pain is frequently a cause of reduced quality of life in physically active males. The cause of patellofemoral pain is theorized to include aberrant biomechanics during weight-bearing activities. Altered biomechanics of females with patellofemoral pain have been reported, but there is a dearth of research for males with this condition. This study aimed to compare males with and without patellofemoral pain for hip and knee joint moments and muscle activation during single-leg-squatting and proximal muscle strength.

METHODS: Twenty males with patellofemoral pain and 20 pain-free males aged 20-39 years performed single-leg-squatting while motion, ground reaction force, and proximal …

Electromyography, Prosthetic Properties, And Running Biomechanics In Recreationally Active Persons With Lower Extremity Amputation, Paige M. Agnew

Rehabilitation Sciences Theses & Dissertations

Lower extremity loss affects nearly 150,000 individuals in the United States yearly yielding extreme health care costs annually. Typically, prosthetic devices are prescribed for 5-8 years despite known changes to an individual’s gait as time progresses. Patients can expect to undergo approximately 8-12 weeks of gait retraining to improve their comfort and efficiency. Biomechanical changes occur when running with a specific running prosthetic including considerable biomechanical and neuromuscular interlimb asymmetries and alterations in loading patterns. The purpose of this dissertation was to investigate the biomechanical demands for lower extremity prosthesis users during running. The first study synthesized peer reviewed evidence …

The Association Of Acute Stress And Lower Quarter Emg During A Single Leg Balance Dexterity Task, Ted W. Gehrig Iii, Robert I. Dudley, Jo Armour Smith, Lida Gharibvand, Lee S. Berk, Everett B. Lohman Iii

Physical Therapy Faculty Articles and Research

Background

Research Question

Methods

Sex Differences In Motor Unit Behavior In Patients With Parkinson's Disease, Yuichi Nishikawa, Kohei Watanabe, Aleš Holobar, Tetsuya Takahashi, Noriaki Maeda, Hirofumi Maruyama, Allison Hyngstrom

Physical Therapy Faculty Research and Publications

The aim of this study was to determine whether there are sex differences in motor unit firing behavior in patients with Parkinson's disease. Twenty-seven patients with Parkinson's disease (females = 14 [age = 71.1 ± 6.8], males = 13 [age = 69.2 ± 10.3], Unified Parkinson's Disease Rating Scale Part III score; females = 10.8 ± 4.8, males = 11.4 ± 1.4) performed a contraction at 30% of the maximal voluntary contraction. For each participant, motor unit spike trains were decomposed from high-density surface electromyography data recorded from bilateral vastus lateralis muscles via blind source separation algorithms. In addition to …

The Influence Of Intrinsic Foot Muscles In Modulating Foot Shape Relative To Substrate And The Efficacy Of Different Strengthening Approaches, Luke R. Lotsis

Masters Theses, 2020-current

Cross-sloped surfaces create an asymmetrical substrate for foot contact, introducing a slip force within the transverse plane and a gravitational pull within the coronal plane that increases the tendency to topple downslope. To maintain stability, the foot must make structural adjustments across the hindfoot, midfoot, forefoot, and hallux. In chapter 1, I investigated how IFMs respond to varying substrate conditions and balance demands, providing insight into their functional role in maintaining stability and adapting foot structure in static and dynamic locomotor tasks. Twenty-four healthy adults participated in a series of dynamic walking trials on flat, cross-sloped and sandy substrates and …

A Simple, Low-Cost Implant For Reliable Diaphragm Emg Recordings In Awake, Behaving Rats, Taylor C. Holmes, Jesus D. Penaloza-Aponte, Alyssa R. Mickle, Rachel L. Nosacka, Erica A. Dale, Kristi A. Streeter

Physical Therapy Faculty Research and Publications

Breathing is a complex neuromuscular process vital to sustain life. In preclinical animal models, the study of respiratory motor control is primarily accomplished through neurophysiologic recordings and functional measurements of respiratory output. Neurophysiologic recordings that target neural or muscular output via direct nerve recordings or respiratory muscle electromyography (EMG) are commonly collected during anesthetized conditions. While offering tight control of experimental preparations, the use of anesthesia results in respiratory depression, may impact cardiovascular control, eliminates the potential to record volitional nonventilatory behaviors, and can limit translation. Since the diaphragm is a unique muscle which is rhythmically active and difficult to …

A Case Report Of Long-Latency Evoked Diaphragm Potentials After Exposure To Acute Intermittent Hypoxia In Post-West Nile Virus Meningoencephalitis, Joseph F. Welch, Erica A. Dale, Jayakrishnan Nair, Paul W. Davenport, Emily J. Fox, Gordon S. Mitchell

Department of Physical Therapy Faculty Papers

We present a case report of a 42-year-old female with post-West Nile virus meningoencephalitis who exhibited unique, long-latency diaphragm potentials evoked by transcranial and cervical magnetic stimulation after exposure to acute intermittent hypoxia (AIH). The subject was recruited for a study investigating AIH effects on respiratory motor function in healthy individuals. She had contracted West Nile virus infection 5 years before assessment that resulted in hospitalization and persistent allodynia but was not reported to the research team. During the study, transcranial (TMS) and cervical (CMS) magnetic stimulation were performed before and 30-60 min after a single presentation of AIH [15, …

The Reverse Lunge: A Descriptive Electromyographic Study, Barbara J. Hoogenboom, Madison Ferguson, Zac Krauss, Stephanie Tran

Open Access Publishing Support Funded Articles

Limited studies exist examining the reverse lunge. The purpose of this study was to describe the activation of the rectus femoris (RF), biceps femoris (BF), gluteus medius (GMed), and gluteus maximus (GMax) of both limbs during a bodyweight reverse lunge movement. A secondary purpose was to describe the phases of the stationary (non-moving) and lead (moving) limbs during the reverse lunge. Surface electromyography (EMG) was used to record the activity of the target muscles in 20 healthy adults (10 male, 10 female; aged 22–25). Root mean squared values for mean maximum and average percent activation normalized to maximum voluntary isometric …

Immediate Effect Of Local Vibration On Motor Unit Firing Behavior And Muscle Strength In Healthy Young Adult Males, Yuichi Nishikawa, Aleš Holobar, Kohei Watanabe, Toshihiko Komatsuzaki, Takanori Chihara, Jiro Sakamoto, Takashi Kawagoe, Hidetaka Nagayasu, Kyoko Mori, Kenji Kawano, Noriaki Maeda, Shinobu Tanaka, Allison S. Hyngstrom

Physical Therapy Faculty Research and Publications

Purpose

The aim of this study was to examine the effect of vibration on motor unit (MU) firing behavior and physical performance of antagonist muscles in healthy young adult males.

Methods

Fourteen males (age = 24.3 ± 3.6 years) were included in this study. There were two conditions, one in which participants received 80 Hz vibration in the distal tendon of the hamstring for 30 s and the control condition (no vibration). High-density surface electromyography (HD-SEMG) signals and maximal voluntary contraction (MVC) of knee extensor muscles were evaluated before and after the respective conditions and recorded from the vastus lateralis …

The Effectiveness Of Temporary Deafferentation For Upper Limb Rehabilitation, Chelsea Erazo Macias, Daniel Salinas, Monica Lozano Garcia, Victoria Cuello, Kelsey Baker

Research Symposium

Background: Temporary deafferentation (TD) is an approach that has been investigated in rehabilitation practices to improve motor function in people with spinal cord injuries. The overall goal of temporary deafferentation is to voluntarily reduce sensory input into the nervous system to improve efferent output. Temporary deafferentation is typically achieved using either topical or injectable anesthetics. Recently, our group sought to optimize a protocol for temporary deafferentation using topical anesthetic cream, and results suggested that temporary deafferentation was achieved 50 minutes after anesthetic cream application. Here, we aimed to determine if our optimized protocol impacted limb electromyography (EMG) after the intervention. …

Bone–Patellar Tendon–Bone Autograft Harvest Prolongs Extensor Latency During Gait 2 Yr After Aclr, Naoaki Ito, Jacob J. Capin, Ashutosh Khandha, Thomas S. Buchanan, Karin Grävare Silbernagel, Lynn Snyder-Mackler

Physical Therapy Faculty Research and Publications

Purpose

Bone–patellar tendon–bone (BPTB) graft harvest for anterior cruciate ligament reconstruction alters patellar tendon properties, which inflict poor quadriceps neuromuscular function. BPTB autografts are associated with higher rates of posttraumatic osteoarthritis, which in turn is associated with pathological gait. The purpose of this study was to investigate the latency between the time of peak quadriceps activity and the peak knee flexion moment during gait, between those with BPTB grafts (n = 23) and other graft types (hamstring autograft or allografts, n = 54), 5 ± 2 months and 2 yr (25 ± 3 months) after anterior cruciate ligament reconstruction. …

Identifying Gait Pathology After Acl Reconstruction Using Temporal Characteristics Of Kinetics And Electromyography, Naoaki Ito, Jacob J. Capin, Ashutosh Khandha, Thomas S. Buchanan, Lynn Snyder-Mackler

Physical Therapy Faculty Research and Publications

Purpose

Asymmetrical gait mechanics after anterior cruciate ligament reconstruction (ACLR) are associated with the development of posttraumatic knee osteoarthritis. Current measures of gait mechanics have focused heavily on peak magnitudes of knee kinematics, kinetics, and joint contact forces but have seldom considered the rate of knee loading, cumulative knee load, or the timing of motor input surrounding peaks. The purpose of this study was to introduce and describe novel metrics of gait using temporal characteristics of kinetics and EMG to identify neuromuscular deficits of the quadriceps in patients after ACLR.

Methods

Gait mechanics were assessed 6 months (n = …

Lower Extremity And Trunk Electromyographic Muscle Activity During Performance Of The Y-Balance Test On Stable And Unstable Surfaces., Navpreet Kaur, Kunal Bhanot, Germaine Ferreira

Physical Therapy Collection

Background: The Star Excursion Balance Test (SEBT) has been used as a rehabilitation exercise. To improve its efficacy, efficiency, and method variations, the Y-Balance Test (YBT) with anterior (A), posterolateral (PL), and posteromedial (PM) directions of the SEBT has been recommended. Electromyographic activity has been reported to change when the same task is performed on various surfaces.

Hypothesis/Purpose: To compare the EMG activity of trunk and LE muscles during the performance of the YBT on stable and unstable surfaces.

Study Design: Cross-Sectional study.

Methods: Healthy adults with no history of chronic ankle instability were recruited for the study. …

Hip Muscle Function In Individuals With Chronic Ankle Instability, Lindsay Carroll

Electronic Theses and Dissertations

Purpose: Hip muscle function has been reported to be altered in individuals with chronic ankle instability (CAI). The purpose of this study was (1) to determine whether the single leg squat test (SLST) could be used to detect differences in proximal muscle activation between individuals with and without CAI and (2) to determine if there was a difference in maximum isometric body weight normalized torque output of the hip lateral rotators, extensors, and abductors between individuals with and without CAI.

Subjects: Forty-eight subjects (14 males, 34 females; median age = 22.00 years, interquartile range (IQR) = 1.00; median height = …

Co-Contraction Of Ankle Muscle Activity During Quiet Standing In Individuals With Incomplete Spinal Cord Injury Is Associated With Postural Instability, Kai Lon Fok, Jae W Lee, Janelle Unger, Katherine Chan, Kristin E Musselman, Kei Masani

Physical Therapy Publications

Previous findings indicate that co-contractions of plantarflexors and dorsiflexors during quiet standing increase the ankle mechanical joint stiffness, resulting in increased postural sway. Balance impairments in individuals with incomplete spinal cord injury (iSCI) may be due to co-contractions like in other individuals with reduced balance ability. Here we investigated the effect of co-contraction between plantar- and dorsiflexors on postural balance in individuals with iSCI (iSCI-group) and able-bodied individuals (AB-group). Thirteen able-bodied individuals and 13 individuals with iSCI were asked to perform quiet standing with their eyes open (EO) and eyes closed (EC). Kinetics and electromyograms from the tibialis anterior (TA), …

Neuromuscular Response To A Single Session Of Whole-Body Vibration In Children With Cerebral Palsy: A Pilot Study, Huaqing (Virginia) Liang, Gena Henderson, Jianhua Wu

Physical Therapy Faculty Research

Background Whole-body vibration (WBV) is a relative new intervention paradigm that could reduce spasticity and improve motor function in children with cerebral palsy (CP). We investigated neuromuscular response to a single session of side-alternating WBV with different amplitudes in children with CP.

Methods Ten children with spastic CP aged 7–17 years at GMFCS level I-III participated in this pilot study. Participants received two sessions of side-alternating WBV with the same frequency (20 Hz) but different amplitudes (low-amplitude: 1 mm and high-amplitude: 2 mm). Each session included six sets of 90 s of WBV and 90 s of rest. Before and …

Pre-Stretching Of The Hamstrings Before Squatting Acutely Increases Biceps Femoris Thickness Without Impairing Exercise Performance, Thiago Barbosa Trindade, Leônidas Oliveira Neto, José Claudino Neto Pita, Vagner Deuel De Oliveira Tavares, Paulo Moreira Silva Dantas, Brad J. Schoenfeld, Jonato Prestes

Publications and Research

Background: Bilateral squat exercise is widely used in resistance training (RT) programs to increase lower limb strength and muscle mass, but this exercise does not result in significant hypertrophy of the hamstrings. It has been speculated that stretching between sets with a certain degree of tension results in muscle hypertrophy, while acute stretching could decrease performance during maximal contractions.

Objective: This study investigated the acute effects of hamstring stretching before bilateral squatting on muscle thickness (MT), electromyography (EMG), and total training volume (TTV) on exercise performance.

Methods: Fourteen resistance-trained young men, with ∼7.5 years of RT experience, performed the 10 …

Comparison Of Pre- And Post-Operative Shoulder Muscle Emg Profiles In Reverse Total Shoulder Arthroplasty Patients, Emily Lau, Sreten Franovic, Noah Kuhlmann, Eric C. Makhni Md, Stephanie Muh Md

Medical Student Research Symposium

Background: Deltoid muscle function is central in reverse total shoulder arthroplasty (RTSA) function; however, there is limited information available regarding changes in deltoid activity before and after surgery. Few tests exist to evaluate specific muscle metrics pre and post operatively. Surface Electromyographic (EMG) is non-invasive and allows for observation of motions with multifaceted analysis of movement with minimal patient demand. Understanding the changes in shoulder muscle activation, namely in the deltoid, in patients pre and post-RTSA can further advance understanding of the procedure and rehabilitation efforts.

Methods: Nine individuals were recruited for this study: all patients underwent RTSA by a …

Reactive Stepping After A Forward Fall In People Living With Incomplete Spinal Cord Injury Or Disease, Katherine Chan, Jae Woung Lee, Janelle Unger, Jaeeun Yoo, Kei Masani, Kristin E Musselman

Physical Therapy Publications

STUDY DESIGN: Cross sectional.

OBJECTIVES: To compare the reactive stepping ability of individuals living with incomplete spinal cord injury or disease (SCI/D) to that of sex- and age-matched able-bodied adults.

SETTING: A tertiary SCI/D rehabilitation center in Canada.

METHODS: Thirty-three individuals (20 with incomplete SCI/D) participated. Participants assumed a forward lean position in standing whilst 8-12% of their body weight was supported by a horizontal cable at waist height affixed to a rigid structure. The cable was released unexpectedly, simulating a forward fall and eliciting one or more reactive steps. Behavioral responses (i.e., single step versus non-single step) were compared …

Task-Invariance And Reliability Of Anticipatory Postural Adjustments In Healthy Young Adults, Jo Armour Smith, Niklas König Ignasiak, Jesse V. Jacobs

Physical Therapy Faculty Articles and Research

Background

Anticipatory postural adjustments (APAs) occur in the trunk during tasks such as rapid limb movement and are impaired in individuals with musculoskeletal and neurological dysfunction. To understand APA impairment, it is important to first determine if APAs can be measured reliably and which characteristics of APAs are task-invariant.

Research question

What is the test-retest reliability of latency, amplitude and muscle activation patterns (synergies) of trunk APAs during arm-raise and leg-raise tasks, and to what extent are these APA characteristics invariant across tasks at the individual and group levels?

Methods

15 young adults (mean age: 23.7 (±3.2) years) performed six …

Muscle Activation Patterns During Movement Attempts In Children With Acquired Spinal Cord Injury: Neurophysiological Assessment Of Residual Motor Function Below The Level Of Lesion., Darryn A Atkinson, Laura Mendez, Natalie Goodrich, Sevda C Aslan, Beatrice Ugiliweneza, Andrea L Behrman

Physical Therapy Collection

Introduction: Characterization of residual neuromotor capacity after spinal cord injury (SCI) is challenging. The current gold standard for measurement of sensorimotor function after SCI, the International Society for Neurological Classification of Spinal Cord Injury (ISNCSCI) exam, seeks to determine isolated intentional muscle activation, however many individuals with SCI exhibit intentional movements and muscle activation patterns which are not confined to specific joint or muscle. Further, isolated muscle activation is a feature of the neuromuscular system that emerges during development, and thus may not be an appropriate measurement standard for children younger than 6.

Methods: We utilized neurophysiological assessment …

Individuals With Recurrent Low Back Pain Exhibit Significant Changes In Paraspinal Muscle Strength After Intramuscular Fine Wire Electrode Insertion, Szu-Ping Lee, Vincent Dinglasan, Anthony Duong, Russell Totten, Jo Armour Smith

Physical Therapy Faculty Articles and Research

Objective

To examine how insertion and presence of intramuscular fine‐wire electromyography electrodes (IFWE) in lumbar multifidus affect paraspinal muscle strength, endurance, and activation in persons with and without recurrent lower back pain (RLBP) during activities that require high levels of muscle contraction.

Design

Case‐control with randomization of conditions.

Setting

Clinical Research Laboratory.

Participants

Forty participants age 18‐40 were recruited (18 female; mean age = 25.5 yr); 20 with a history of RLBP were compared to a matching control group of 20 without RLBP.

Interventions

Each participant was tested under three conditions over three sessions. On Session 1, the baseline condition, …

Calculating Set-Volume For The Limb Muscles With The Performance Of Multi-Joint Exercises: Implications For Resistance Training Prescription, Brad J. Schoenfeld, Jozo Grgic, Cody Haun, Takahiro Itagaki, Eric R. Helms

Publications and Research

Resistance training volume, determined by the number of sets performed (set-volume) is considered one of the key variables in promoting muscle hypertrophy. To better guide resistance exercise prescription for weekly per-muscle training volume, the purpose of this paper is to provide evidence-based considerations for set-volume ratios between multi-joint (MJ) and single-joint (SJ) exercises so that practitioners can better manage prescription of training volume in program design. We analyzed this topic from three primary areas of focus: (1) biomechanical and physiological factors; (2) acute research; and (3) longitudinal research. From a biomechanical and physiological standpoint, when considering force production of different …

Hip And Trunk Muscle Activity During The Star Excursion Balance Test In Healthy Adults, Kunal Bhanot, Navpreet Kaur, Lori Thein Brody, Jennifer Bridges, David C. Berry, Joshua J. Ode

Physical Therapy Collection

CONTEXT: Dynamic balance is a measure of core stability. Deficits in the dynamic balance have been related to injuries in the athletic populations. The Star Excursion Balance Test (SEBT) is suggested to measure and improve dynamic balance when used as a rehabilitative tool.

OBJECTIVE: To determine the electromyographic activity of the hip and the trunk muscles during the SEBT.

DESIGN: Descriptive.

SETTING: University campus.

PARTICIPANTS: Twenty-two healthy adults (11 males and 11 females; 23.3 [3.8] y, 170.3 [7.6] cm, 67.8 [10.3] kg, and 15.1% [5.0%] body fat).

INTERVENTION: Surface electromyographic data were collected on …

Neuromuscular Adaptions Following A Daily Strengthening Exercise In Individuals With Rotator Cuff Related Shoulder Pain: A Pilot Case-Control Study, Amee L. Seitz, Lisa A. Podlecki, Emily R. Melton, Timothy L. Uhl

Physical Therapy Faculty Publications

Background: The goal of therapeutic exercise is to facilitate a neuromuscular response by increasing or decreasing muscular activity in order to reduce pain and improve function. It is not clear what dosage of exercise will create a neuromuscular response.

Purpose: The purpose of this study was to assess the effects following a three-week home program of a daily single exercise, the prone horizontal abduction exercise (PHA), on neuromuscular impairments of motor control as measured by scapular muscle EMG amplitudes, strength, and secondarily outcomes of self-reported pain and function between individuals with and without subacromial pain syndrome.

Study Design: Prospective Case-Control, …

Electromyographic (Emg) Activity Of The Gluteus Medius During Various Hip Exercises, Kalie Maiden, Mitchell Karbo, Taylor Doeden, Analise Richtsmeier

Physical Therapy Scholarly Projects

Background and Purpose. The purpose of the study was to record and analyze muscle recruitment patterns of the gluteus medius and gluteus maximus muscles when performing a side lying abduction exercise requiring consistent force to roll a ball up and down the wall using the dominant lower extremity. Comparisons were made between the use of either a small, medium or large ball. The subjects performed a standing abduction exercises with theraband around both ankles as well.

Case Description. Fifteen subjects were recruited from the University of North Dakota Department of Physical Therapy to perform the four different types of exercises. …

Emg Analysis Of Latissimus Dorsi, Middle Trapezius, And Erector Spinae Muscle Activity During Spinal Rotation: A Pilot Study, Alyssa Wagner, Brandon Forister, Zachary Huot

Physical Therapy Scholarly Projects

Purpose/Hypothesis: Rotation of the spine is a common movement used to complete daily activities and participate in sports. As a contributing factor to back injuries, the performance of spinal rotation is an important consideration for the rehabilitation of current and prevention of future back injuries. Muscles involved in spinal rotation have been researched, though limited findings exist for one of the largest back muscles, the Latissimus Dorsi (LD). The LD muscle contributes to many movements of the trunk and limbs given its multiple attachment sites including the pelvis, ribs, scapula, and humerus. Influence of the LD on spinal rotation has …

Insertion And Presence Of Fine-Wire Intramuscular Electrodes To The Lumbar Paraspinal Muscles Do Not Affect Muscle Performance And Activation During Highexertion Spinal Extension Activities, Szu-Ping Lee, Jo Armour Smith, Matthew Kimber, Kelsey Houk

Physical Therapy Faculty Articles and Research

Background

Low back pain (LBP) is commonly associated with paraspinal muscle dysfunctions. A method to study deep lumbar paraspinal (i.e. multifidus) muscle function and neuromuscular activation pattern is intramuscular electromyography (EMG). Previous studies have shown that the procedure does not significantly impact muscle function during activities involving low-level muscle contractions. However, it is currently unknown how muscular function and activation are affected during high-exertion contractions.

Objective

To examine the effects of insertion and presence of fine-wire EMG electrodes in the lumbar multifidus on muscle strength, endurance, and activation profiles during high-exertion spinal extension muscle contractions.

Design

Single-blinded, repeated measures intervention …

Individuals With Recurrent Low Back Pain Exhibit Significant Changes Of Paraspinal Muscle Performance After Lumbar Multifidus Intramuscular Fine Wire Electrode Insertion, Anthony Duong, Vincent Dinglasan, Russell Totten

UNLV Theses, Dissertations, Professional Papers, and Capstones

STUDY DESIGN: Case control study. BACKGROUND: Recurrent low back pain (RLBP) is associated with paraspinal muscle dysfunction. Intramuscular electromyography (EMG) is a common tool for studying activation of the deep lumbar paraspinal muscles such as multifidi muscles, but it is currently currently unclear how muscle performance and activation are affected by the pain and micro-injury associated with intramuscular fine-wire electrode (IFWE) insertion and how it interacts with the presence of RLBP. OBJECTIVES: The purpose of this study was to examine how IFWE insertion into the lumbar multifidus affects paraspinal muscle strength and endurance in subjects with and without RLBP. METHODS: …