Stuart M Mcgill

University of Waterloo | UWaterloo · Department of Kinesiology

Knee valgus during landing has been identified as a strong correlate of ACL injury. Inappropriate trunk control during landing contributes to high knee valgus, with neuromuscular factors related to core stability postulated as the mechanism. This investigation probed the influence of trunk and hip mechanics, including joint stiffness, on knee mecha...

When muscles contract, they create force and stiffness. Thus, muscle activation and relaxation must be strategically sequenced to coordinate and control movement, to enhance athletic variables such as speed and strength. However, research has favored investigation of muscle activation over relaxation. Athletes such as runners, swimmers, and boxers...

Spine loading data are needed to design low-back health-preserving ergonomic interventions for firefighters. Study objectives were to quantify spine loads during simulated fireground operations using simple (polynomial) and advanced (EMG-assisted musculoskeletal model) methods, and to describe the variation in spine loads between performers (N = 20...

Study design: Cross-sectional. Background: Neuromuscular deficits at the trunk and hip may contribute to dynamic knee valgus and anterior cruciate ligament (ACL) injury mechanisms. However, comprehensive examination of neuromuscular patterns and their mechanical influence are lacking. Objective: To investigate the influence of lumbar spine joi...

Background Disc height loss and osteophytes change the local mechanical environment in the spine; while previous research has examined kinematic dysfunction under degenerative change, none has looked at the influence of disc height loss and osteophytes throughout movement. Methods Twenty patients with pain related to the head, neck or shoulders we...

The motions of individual intervertebral joints can affect spine motion, injury risk, deterioration, pain, treatment strategies, and clinical outcomes. Since standard kinematic methods do not provide precise time-course details about individual vertebrae and intervertebral motions, information that could be useful for scientific advancement and cli...

Background: There is limited data available regarding the cost of firefighter injuries. This information is necessary to develop targeted injury prevention strategies. Objective: To categorize the cost of injuries filed in 2012 by firefighters from a from a large department by job duty, injury type, body part affected, and the general motion pat...

Ballistic limb motion is enabled by proximal “core” stiffness. However, controversy exists regarding the best method of training this characteristic. This study sought to determine the most effective core training method to enhance distal limb athleticism. A total of 12 participants (24 ± 3 years, 1.8 ± 0.05 m, 76.8 ± 9.7 kg) consisting of Muay Tha...

?Core? exercise is a basic part of many physical training regimens with goals ranging from rehabilitation of spine and knee injuries to improving athletic performance. Core stiffness has been proposed to perform several functions including reducing pain by minimising joint micro-movements, and enhancing strength and speed performance. This study pr...

Objective: To examine whether objective measures of spine and frontal plane knee motion exhibited during Functional Movement Screen™ (FMS) task performance changed following a movement-guided fitness (MOV) and conventional fitness (FIT) exercise intervention. Design: Secondary analysis of a randomized controlled experiment. Before and after 12 w...

Background context: Compressive fracture can produce profound changes to the mechanical profile of a spine segment. Minimally invasive repair has the potential to restore both function and structural integrity to an injured spine. Use of both hydrogels to address changes to the disc, combined with polymethyl methacrylate (PMMA) to address changes...

Background: Height loss can have a profound influence on the local mechanical environment of the disc. While disc height loss is incorporated into scales of degeneration, its direct influence on spine kinematics is unclear. Further, there is a need for minimally invasive techniques to restore disc height; injectable hydrogels are a potential solut...

Objective: The purpose of this study was to evaluate the ability of a pneumatic decompression belt to restore spinal height lost following an acute bout of exercise that induced compression. Methods: This study implemented a test-retest repeated measures design in which twelve participants (male = 10, female = 2) age, 21.5 ± 1.0 years; height, 1...

Background context: Defects in the annulus fibrosus (AF) remain a challenge in the surgical treatment of lumbar disc herniations with persistent defects, allowing potential re herniation of nucleus pulposus (NP) tissue. A cervical porcine model was chosen to simulate human lumbar intervertebral disc (IVD). Purpose: The aim of this study was to d...

THE PURPOSE OF THIS ARTICLE IS TO EXPAND A CONCEPT SURROUNDING THE ROTATIONAL FUNCTION AND TRAINING OF THE BODY'S CORE. MORE THAN A DECADE AGO, A MODEL WAS PROVIDED BY WHICH TO OBSERVE AND TRAIN THE CORE, WHICH WAS BASED ON A PREVIOUSLY PUBLISHED THEORY REGARDING THE SERAPE EFFECT. THE PURPOSE OF THIS ARTICLE IS TO EXPAND ON THAT MODEL, THE ORIGINA...

Geared for the lay public with back pain, Professor McGill guides the reader through a self assessment to identify their specific pain triggers. This knowledge is then used to guide how to avoid the pain triggers (remove the cause) followed by an exercise progression matched to the patient. Like all of McGill's textbooks, the guidance is evidence b...

Background: Linking firefighter injury reporting to general motion patterns may provide insight into potential injury mechanisms and the development of prevention strategies. Objective: To characterize the injuries sustained by members of a large Canadian metropolitan fire department over a 5-year span. Methods: Data were taken from injury rep...

Elite police work has bursts of intense physically demanding work requiring high levels of fitness, or capacity, and movement competency; which are assumed to increase one's injury resilience. The purpose of this study was to follow members of an elite police force (N = 53) to test whether back injuries (N = 14) could be predicted from measures of...

THE BACK SQUAT IS A WELL-RESEARCHED AND WIDELY USED EXERCISE TO ENHANCE FUNDAMENTAL MOVEMENT COMPETENCY THAT CREATES A FOUNDATION FOR OPTIMAL MECHANICAL STRATEGIES DURING A BROAD RANGE OF ACTIVITIES. THE PRIMARY COMMENTARY INTRODUCED THE BACK SQUAT ASSESSMENT (BSA): A CRITERION-BASED ASSESSMENT OF THE BACK SQUAT THAT DELINEATES 30 POTENTIALLY OBSER...

There is a substantial interest in identifying interventions that can protect and buffer older adults from atrophy in the cortex and particularly, the hippocampus, a region important to memory. We report the 2-year effects of a randomized controlled trial of an intergenerational social health promotion program on older men's and women's brain volum...

While core stiffness enhances athletic performance traits controversy exists regarding the effectiveness of isometric vs dynamic core training methods. This study aimed to determine if long term changes in stiffness can be trained, and if so, what is the most effective method. Twenty four healthy male subjects (23 ± 3 years, 1.8 ± 0.06 m, 77.5 ± 10...

Using exercise to enhance physical fitness may have little impact on performers' movement patterns beyond the gym environment. This study examined the fitness and movement adaptations exhibited by firefighters in response to two training methodologies. Fifty-two firefighters were assigned to a movement-guided fitness (MOV), conventional fitness (FI...

The primary objective was to examine the utility of a novel method of detecting "actual" kinematic changes using the within-subject variation. Twenty firefighters were assigned to one of two groups (lifting or firefighting). Participants performed 25 repetitions of two lifting or firefighting tasks, in three sessions. The magnitude and within-subje...

We examined the impact of the Experience Corps(®) (EC) program on school climate within Baltimore City public elementary schools. In this program, teams of older adult volunteers were placed in high intensity (>15 h per week), meaningful roles in public elementary schools, to improve the educational outcomes of children as well as the health and we...

Study Design Biomechanical study on cadaveric spines. Objective Spinal bending causes the annulus to pull vertically (axially) on the end plate, but failure mechanisms in response to this type of loading are poorly understood. Therefore, the objective of this study was to identify the weak point of the intervertebral disk in tension. Methods Cada...

To examine the relationship between the composite Functional Movement Screen (FMS) score and performers' spine and frontal plane knee motion. Examined the spine and frontal plane knee motion exhibited by performers who received high (>14) and low (<14) composite FMS scores. Participants' body motions were quantified while they performed the FMS. Bi...

Unlabelled: An international consensus process resulted in exercise and physical activity recommendations for individuals with osteoporosis. Emphasis was placed on strength, balance, and postural alignment. Rather than providing generic restrictions, activity should be encouraged while considering impairments, fracture risk, activity history, and...

Fundamental movement competency is essential for participation in physical activity and for mitigating the risk of injury, which are both key elements of health throughout life. The squat movement pattern is arguably one of the most primal and critical fundamental movements necessary to improve sport performance, to reduce injury risk and to suppor...

ABSTRACT Poor low back muscle endurance has been shown to be a predictor of chronic low back pain. While posture is a modulator of low back muscle endurance, it is unclear whether the phenomenon is neural or mechanical. This study examined low back muscle endurance with changing head and neck posture in a sample of 117 children using the Biering-Sø...

Purpose: To describe female lumbar spine motion and posture characteristics during coitus and compare these characteristics across five common coital positions. Exacerbation of low back pain during coital movements and positions is a prevalent issue reported by female low back pain (LBP) patients. To address this problem, the first study to examin...

This study examined several pulling exercises performed on stable surfaces and unstable suspension straps. Specific questions addressed included: which exercises challenged particular muscles, what was the magnitude of resulting spine load, and did technique coaching influence results. Fourteen males performed pulling tasks while muscle activity, e...

Objective To assess the segmental specificity, or accuracy, of osteopathic lumbar spinal manipulations. Background Prior studies of chiropractic technique of manual manipulations of the spine designed to target abnormal tissue have been shown to be inaccurate, resulting in adjustments of segments other than the targeted level. This can result in m...

Novel ideas for core endurance training are continually being created. However, studies of their mechanism of action assist in evaluation of their potential as a training tool, for a variety of people and purposes. The specific purpose of this study was to evaluate a weighted hula hooping training program for its efficacy on improving core muscular...

Study design: Repeated measures design. Objective: To describe male spine movement and posture characteristics during coitus and compare these characteristics across 5 common coital positions. Summary of background data: Exacerbation of pain during coitus due to coital movements and positions is a prevalent issue reported by low back pain pati...

Abstract This study examined anterior chain whole body linkage exercises, namely the body saw, hanging leg raise and walkout from a push-up. Investigation of these exercises focused on which particular muscles were challenged and the magnitude of the resulting spine load. Fourteen males performed the exercises while muscle activity, external force...

Bone fragments have been identified in the material of many intervertebral disc herniations. The mechanism by which this occurs or exact source of these fragments remains to be determined. Further, the morphology of bone damage in the vertebral body before and after herniation has not been characterized. This study sought to determine the location...

With the growing popularity of Mixed Martial Arts (MMA) as a competitive sport, questions regarding the dynamic response and properties of MMA gloves arise. High-energy impacts from punches are very similar to boxing yet MMA competition requires the use of 4 oz fingerless glove, compared to the larger full enclosure boxing glove. This work assessed...

Background: Within the context of evaluating individuals' movement behavior it is generally assumed that the tasks chosen will predict their competency to perform activities relevant to their occupation. Objective: This study sought to examine whether a battery of general tasks could be used to predict the movement patterns employed by firefight...

The impact of exercise on firefighter job performance and cardiorespiratory fitness has been studied extensively, but its effect on musculoskeletal loading remains unknown. The aim of this study was to contrast the physical fitness and low-back loading outcomes of two groups of firefighters who completed different exercise programmes. Before and af...

An international consensus process identified the following research priorities in osteoporosis and exercise: study of exercise in high-risk cohorts, evaluation of multimodal interventions, research examining translation into practice and a goal to examine fracture outcomes. To identify future research priorities related to exercise for people with...

Experience Corps (EC) represents a high-intensity, intergenerational civic engagement activity where older adults serve as mentors and tutors in elementary schools. Although high-intensity volunteer opportunities are designed to enhance the health and well being of older adult volunteers, little is known about the negative and positive aspects of v...

The AARP Experience Corps® program is an innovative, community-based health promotion model that incorporates the time, experience, and wisdom of older adults to improve academic and behavioral outcomes of kindergarten through third-grade children in public elementary schools. The Experience Corps program was simultaneously designed by public healt...

Electromyographic (EMG) signals have many uses. This chapter addresses the role of EMG signals to assess joint stability. Low back pain assessment and treatment interventions often involve the concepts of stability and/or joint stiffness. Using muscle activation and lumbar spine posture to calculate segmental stiffness and potential energy of the s...

The objective of this study was to analyze trunk and shoulder muscle activation and lumbar spine kinematics of backward and forward phases during both isolated medicine-ball side throws, and medicine-ball side catch and throw sequences. Thirteen recreationally trained men performed three isolated medicine-ball side throws with 1 min rest between re...

The abdominal wall is a prime target for therapeutic exercises aimed to prevent and rehabilitate low back pain as well as enhance performance training. This study examined the "Lewit"; a corrective exercise prescribed for several purposes, which is performed lying supine in a crook-lying position and involves forceful breathing. Muscle activation a...

A consensus process was conducted to develop exercise recommendations for individuals with osteoporosis or vertebral fractures. A multicomponent exercise program that includes balance and resistance training is recommended. The aim was to develop consensus on exercise recommendations for older adults: (1) with osteoporosis and (2) with osteoporotic...

Deficits in joint mobility and/or stability could certainly impact individuals' Functional Movement Screen (FMS) scores; however, it is also plausible that the movement patterns observed are influenced by the performers' knowledge of the grading criteria. Twenty-one firefighters volunteered to participate and their FMS scores were graded before and...

Objective: The aim of this study was to establish normative values for torso muscle endurance in adolescents aged 15-18 years. It was hypothesized that torso endurance profiles of adolescents differs between males and females and between adolescents and adults. Background: Decreased torso muscle endurance has been identified as a potential perso...

Because individuals' movement patterns have been linked to their risk of future injury, movement evaluations have become a topic of interest. However, if individuals adapt their movement behavior in response to the demands of a task, the utility of evaluations comprising only low demand activities could have limited application with regards to the...

Labile surfaces in the form of suspension straps are increasingly being utilized as a tool in resistance training programs. Pushing is a common functional activity of daily living and inherently part of a well-rounded training program. This study examined pushing exercises performed on stable surfaces and unstable suspension straps, specifically mu...

The purpose of this cross-sectional study was to examine mean values of isometric torso muscle profiles of four spinal postures (good posture, thoracic kyphosis, lumbar lordosis and scoliosis) among 743 children from the ages of 7 to 14 years old. It was hypothesized that having good posture, thoracic hyper-kyphosis, lumbar hyper-lordosis and scoli...

The authors of an article in this issue of Archives of Physical Medicine and Rehabilitation have advanced our understanding of reliability of clinical tests designed to provide insight into suspected facet joint pain generators. Because the issue of reliability influences, and is influenced by, political and clinical issues, my commentary has 2 par...

Experience Corps Baltimore City (EC) is a product of a partnership between the Greater Homewood Community Corporation (GHCC) and the Johns Hopkins Center on Aging and Health (COAH) that began in 1998. EC recruits volunteers aged 55 and older into high-impact mentoring and tutoring roles in public elementary schools that are designed to also benefit...

Repeated flexion and extension of an intervertebral disc has been shown to affect the angular stiffness of spinal motion segments and is a barometer of the mechanical integrity of the disc. A degenerated disc that loses height causes higher levels of stress on the annulus and facet joints which may increase its level of degeneration; restoring disc...

Background As the population ages, older adults are seeking meaningful, and impactful, post-retirement roles. As a society, improving the health of people throughout longer lives is a major public health goal. This paper presents the design and rationale for an effectiveness trial of Experience Corps™, an intervention created to address both these...

: The purpose of this study was to analyze the transference of increased passive hip ROM and core endurance to functional movement. 24 healthy young men with limited hip mobility were randomly assigned to 4 intervention groups: 1)Stretching; 2)Stretching plus hip/spine disassociation exercises; 3)Core endurance; 4)Control. Previous work has documen...

Background: In this case report an incumbent firefighter partially ruptured his right Achilles tendon during a study of the physical demands of firefighting. Methods: Kinematics and kinetics of the lower limbs and trunk were collected while the firefighter performed two simulated fire ground tasks. From this unexpected event, two insights were o...

The purpose of this study was to compare fitness, hip range of motion (ROM) and movement quality of an Emergency Task Force (ETF) police unit across age groups and with other populations. ETF had poorer hip ROM and back torso endurance compared to other cohorts which are variables linked with back disorders.Relevance to IndustryUnderstanding functi...

Unlabelled: This study investigates the consequences of carrying load in one hand versus both hands. Six participants walked carrying buckets containing various weights. The weight was either carried in one hand or distributed evenly between both hands. Electromyography, force plate and body kinematic data were input to a three-dimensional anatomi...

The aim of this study was to investigate whether torso endurance scores were linked with anthropometric variables in children and to develop a normative scale of anthropometric measures in children in both genders for clinical assessment, rehabilitation, physical education targets and young athletic training pur-poses. It was hypothesized that chan...

Background: Patients and athletes with diminished gluteal muscle activation are thought to have 'gluteal inhibition'. This may be a component of arthrogenic neuromuscular inhibition, which has been well documented in the knee and generalized to all joints. While clinical evidence surrounding gluteal inhibition increases, supportive research is non...

Background/objective: Given the possible links between movement, fitness and injury, the goal of this study was to evaluate strength, endurance, and hip range of motion (ROM) (i.e. fitness); movement quality; and age in a population of firefighters. Participants: Male firefighters (n=282), all members of a major Canadian city fire department, vo...

Study design: A quantitative biomechanical analysis of mechanism of pain alteration in 4 cases of low back pain. Objective: To investigate the contributions of a number of biomechanical factors associated with pain alteration. Summary of background data: Some clinicians use mechanically based manual interventions in attempt to reduce low back...

Objective: To describe the annual operational costs of a mature Experience Corps® program in elementary schools in the Baltimore City Public School System. Methods: Systematic records of expenditures kept by the community partner, Greater Homewood Community Corporation, to be reported to funders were made available for analysis. Expenditures were a...

Repeated flexion of an intervertebral disc has been identified as a mechanism to produce posterior herniations. Repeated extension under certain conditions has also been shown to cause the nucleus of partially herniated discs to reverse and migrate anteriorly. While research shows that the nucleus pulposus migrates anteriorly in extension and infil...

Objective: To establish torso muscle endurance values in children aged 7 to 14 years, as well as ratios between torso extensors, flexors, and lateral torso flexors, with applications in clinical assessment, rehabilitation, physical education targets, and athletic training program designs. It was hypothesized that boys and girls mature differently...

The purpose of this study was to see if specific tests of fitness and movement quality could predict injury resilience and performance in a team of basketball players over 2 years (2 playing seasons). It was hypothesized that, in a basketball population, movement and fitness scores would predict performance scores and that movement and fitness scor...

The aim of this study was to quantify joint compression and shear forces at L4/L5 during exercises used to overload the hips. Nine men performed 36 "walking" trials using two modalities: (1) sled towing and (2) exercise bands placed around the ankles. Participants completed forward, backward, and lateral trials with bent and straight legs at three...

The purpose of this study was to analyze the effect of 3 different exercise interventions plus a control group on passive hip range of motion (ROM). Previous research studies into the methods of improving passive hip mobility have focused on stretching protocols aimed specifically at the hip joint. The effect of core stabilization, motor training,...

Unlabelled: The goal of this study was to establish relationships between fitness (torso endurance, grip strength and pull-ups), hip range of motion (ROM) (extension, flexion, internal and external rotation) and movement quality in an occupational group with physical work demands. Fifty-three men from the emergency task force of a major city polic...

The intent of this study was to quantify spine loading during different kettlebell swings and carries. No previously published studies of tissue loads during kettlebell exercises could be found. Given the popularity of kettlebells, this study was designed to provide an insight into the resulting joint loads. Seven male subjects participated in this...

Having worked with several world champion athletes over the years, I have formed opinions as to what facilitates great performance. This paper summarizes a few observations of mechanical variables that characterize outstanding technique and performance results.

The aim of this study was to compare trunk muscular recruitment and lumbar spine kinematics when motion was constrained to either the thorax or the pelvis. Nine healthy women performed four upright standing planar movements (rotations, anterior-posterior translations, medial-lateral translations, and horizontal circles) while constraining pelvis mo...

The Functional Movement Screen™ (FMS) has demonstrated some efficacy in the prediction of injuries and is thus used by many practitioners to make recommendations for exercise. However, questions remain regarding its utility as a means to evaluate the effectiveness of training. Sixty firefighters volunteered to participate, and their FMS scores were...

Low socioeconomic status (SES) is associated with increased risk for adverse health outcomes; those with low SES are thought to experience greater environmental disadvantage and exposure to chronic stress over the life course. The effects of chronic stress on health have been measured by cortisol levels and variations in their diurnal pattern. Howe...

The Experience Corps® (EC) program is an innovative, community-based model for health promotion for older adults. Incorporating health promotion into new, generative roles for older adults, it brings the time, experience, and wisdom of older adults to bear to improve academic and behavioral outcomes of K-3 grade children in public elementary school...

The relationship between muscle activation, force and stiffness needs to be known to interpret the stability state of the spine. To test the relationship between these variables, a quick release approach was used to match quantified torso stiffness with an EMG activation-based estimate of individual muscle stiffnesses. The relationship between acti...