Changing the Narrative in Diagnosis and Management of Pain in the Sacroiliac Joint Area.

The sacroiliac joint (SIJ) is often considered to be involved when people present for care with low back pain where SIJ is located. However, determining why the pain has arisen can be challenging, especially in the absence of a specific cause such as pregnancy, disease, or trauma, when the SIJ might be identified as a source of symptoms with the help of manual clinical tests. Nonspecific SIJ-related pain is commonly suggested to be causally associated with movement problems in the SIJ(s)-a diagnosis traditionally derived from manual assessment of movements of the SIJ complex. Management choices often consist of patient education, manual treatment, and exercise. Although some elements of management are consistent with guidelines, this Perspective article argues that the assumptions on which these diagnoses and treatments are based are problematic, particularly if they reinforce unhelpful, pathoanatomical beliefs. This article reviews the evidence regarding the clinical detection and diagnosis of SIJ movement dysfunction. In particular, it questions the continued use of assessing movement dysfunction despite mounting evidence undermining the biological plausibility and subsequent treatment paradigms based on such diagnoses. Clinicians are encouraged to align their assessment methods and explanatory models with contemporary science to reduce the risk of their diagnoses and choice of intervention negatively affecting clinical outcomes.

The Role and Value of Symptom-Modification Approaches in Musculoskeletal Practice.

The diversity of models of care in contemporary musculoskeletal physical therapy can be confusing for patients and practicing clinicians. There is, however, a common theme to many of these seemingly disparate models of care: symptom modification. Symptom modification aims at reducing symptoms and improving function with a variety of clinical approaches. This Viewpoint explores the role of symptom modification in rehabilitation and specifically addresses (1) symptom modification within the kinesiopathological model of pain, (2) symptom modification in clinical practice, and (3) potential commonality in seemingly divergent models of clinical practice. J Orthop Sports Phys Ther 2018;48(6):430-435. doi:10.2519/jospt.2018.0608.

Interpreting Signal Amplitudes in Surface Electromyography Studies in Sport and Rehabilitation Sciences.

Surface electromyography (sEMG) is a popular research tool in sport and rehabilitation sciences. Common study designs include the comparison of sEMG amplitudes collected from different muscles as participants perform various exercises and techniques under different loads. Based on such comparisons, researchers attempt to draw conclusions concerning the neuro- and electrophysiological underpinning of force production and hypothesize about possible longitudinal adaptations, such as strength and hypertrophy. However, such conclusions are frequently unsubstantiated and unwarranted. Hence, the goal of this review is to discuss what can and cannot be inferred from comparative research designs as it pertains to both the acute and longitudinal outcomes. General methodological recommendations are made, gaps in the literature are identified, and lines for future research to help improve the applicability of sEMG are suggested.

The modified Thomas test is not a valid measure of hip extension unless pelvic tilt is controlled.

The modified Thomas test was developed to assess the presence of hip flexion contracture and to measure hip extensibility. Despite its widespread use, to the authors' knowledge, its criterion reference validity has not yet been investigated. The purpose of this study was to assess the criterion reference validity of the modified Thomas test for measuring peak hip extension angle and hip extension deficits, as defined by the hip not being able to extend to 0º, or neutral. Twenty-nine healthy college students (age = 22.00 ± 3.80 years; height = 1.71 ± 0.09 m; body mass = 70.00 ± 15.60 kg) were recruited for this study. Bland-Altman plots revealed poor validity for the modified Thomas test's ability to measure hip extension, which could not be explained by differences in hip flexion ability alone. The modified Thomas test displayed a sensitivity of 31.82% (95% CI [13.86-54.87]) and a specificity of 57.14% (95% CI [18.41-90.10]) for testing hip extension deficits. It appears, however, that by controlling pelvic tilt, much of this variance can be accounted for (r = 0.98). When pelvic tilt is not controlled, the modified Thomas test displays poor criterion reference validity and, as per previous studies, poor reliability. However, when pelvic tilt is controlled, the modified Thomas test appears to be a valid test for evaluating peak hip extension angle.

Acute effects of anterior thigh foam rolling on hip angle, knee angle, and rectus femoris length in the modified Thomas test.

Background. Foam rolling has been shown to acutely increase range of motion (ROM) during knee flexion and hip flexion with the experimenter applying an external force, yet no study to date has measured hip extensibility as a result of foam rolling with controlled knee flexion and hip extension moments. The purpose of this study was to investigate the acute effects of foam rolling on hip extension, knee flexion, and rectus femoris length during the modified Thomas test. Methods. Twenty-three healthy participants (male = 7; female = 16; age = 22 ± 3.3 years; height = 170 ± 9.18 cm; mass = 67.7 ± 14.9 kg) performed two, one-minute bouts of foam rolling applied to the anterior thigh. Hip extension and knee flexion were measured via motion capture before and after the foam rolling intervention, from which rectus femoris length was calculated. Results. Although the increase in hip extension (change = +1.86° (+0.11, +3.61); z(22) = 2.08; p = 0.0372; Pearson's r = 0.43 (0.02, 0.72)) was not due to chance alone, it cannot be said that the observed changes in knee flexion (change = -1.39° (-5.53, +2.75); t(22) = -0.70; p = 0.4933; Cohen's d = - 0.15 (-0.58, 0.29)) or rectus femoris length (change = -0.005 (-0.013, +0.003); t(22) = -1.30; p = 0.2070; Cohen's d = - 0.27 (-0.70, 0.16)) were not due to chance alone. Conclusions. Although a small change in hip extension was observed, no changes in knee flexion or rectus femoris length were observed. From these data, it appears unlikely that foam rolling applied to the anterior thigh will improve passive hip extension and knee flexion ROM, especially if performed in combination with a dynamic stretching protocol.

An unstable support surface does not increase scapulothoracic stabilizing muscle activity during push up and push up plus exercises.

BACKGROUND: The aim of the current study is to determine if performing push up exercise variations on an unstable surface (Swiss ball) influences EMG amplitude of the scapulothoracic muscles when compared with a stable surface (Bench). METHODS: Ten males were recruited from a convenience sample of college students. Surface electromyograms were recorded from the upper trapezius, lower trapezius, serratus anterior and biceps brachii while performing push up exercises with the feet or hands placed on a bench and separately on a Swiss ball. A push up plus exercise was also evaluated with hands on the different support surfaces. RESULTS: There was no statistically significant (p<0.05) difference in mean EMG amplitude on a Swiss ball when compared with the same exercise performed on a bench. Significant differences in muscle activity were seen in the upper trapezius and serratus anterior as a result of changes in foot position relative to hand position irrespective of surface stability. INTERPRETATION: The unstable surface used in this study is not a sufficient condition to generate an increase in muscle activity in select scapulothoracic and glenohumeral muscles during push up exercise variations. Elevating the feet above the hands appeared to have a greater influence on shoulder stabilizing musculature amplitude than the addition of a Swiss ball.

Shoulder muscle EMG activity during push up variations on and off a Swiss ball.

BACKGROUND: Surface instability is a common addition to traditional rehabilitation and strength exercises with the aim of increasing muscle activity, increasing exercise difficulty and improving joint proprioception. The aim of the current study was to determine if performing upper body closed kinetic chain exercises on a labile surface (Swiss ball) influences myoelectric amplitude when compared with a stable surface. METHODS: Thirteen males were recruited from a convenience sample of college students. Surface electromyograms were recorded from the triceps, pectoralis major, latissimus dorsi, rectus abdominis and external oblique while performing push up exercises with the feet or hands placed on a bench and separately on a Swiss ball. A push up plus exercise was also evaluated with hands on the support surface. RESULTS AND DISCUSSION: Not all muscles responded with an increase in muscle activity. The pectoralis major muscle was not influenced by surface stability. The triceps and rectus abdominis muscles showed increases in muscle activity only when the hands were on the unstable surface. The external oblique muscle was only influenced by surface stability during the performance of the push up plus exercise. No muscle showed a change in activation level when the legs were supported by the Swiss ball instead of the bench. CONCLUSION: Muscle activity can be influenced by the addition of surface instability however an increase in muscle activity does not influence all muscles in all conditions. The relationship between the participant's center of mass, the location of the unstable surface and the body part contacting the Swiss ball may be important factors in determining the muscle activation changes following changes in surface stability.

Trunk and hip muscle recruitment patterns during the prone leg extension following a lateral ankle sprain: a prospective case study pre and post injury.

UNLABELLED: BACKGROUND AND CASE PRESENTATION: The prone leg extension (PLE) is commonly used to identify dysfunction of muscle recruitment patterns. The prone leg extension is theorized to identify proximal muscle disturbances which are a result of distal injury or dysfunction (i.e. an ankle sprain). This case study compares the trunk and hip muscle (bilateral lower erector spine, ipsilateral hamstring and ipsilateral gluteus maximus) timing during a PLE of a 27 year old female runner during a healthy state (pre ankle sprain) and 2 and 8 weeks post ankle sprain. RESULTS AND DISCUSSION: The gluteus maximus muscle onsets at 8 weeks post injury appeared to occur earlier compared with 2 weeks post injury. The Right Erector Spinae at 8 weeks post injury was also active earlier compared with the participant's non-injured state. A large degree of variability can be noted within trials on the same day for all muscle groups. CONCLUSION: An acute ankle injury did not result in a delay in gluteus maximus muscle activation. The utility of the prone leg extension as a clinical and functional test is questionable due to the normal variability seen during the test and our current inability to determine what is normal and what is dysfunctional.

Resistance training for performance and injury prevention in golf.

This introductory resistance training program is designed to minimize injury risk, improve golf swing speed and the overall fitness of recreational golfers. This article aims to introduce to the Chiropractor the basic concepts sport specific resistance training, periodization models of resistance training and proposes a year round conditioning resistance training program specific to golf. The exercises have been chosen based on the best biomechanical evidence to minimize injury risk and on the research supporting the use of movement specific training adaptations. Upper body strength exercises are performed standing to develop both trunk and hip stabilizing musculature and the primary movement of the golf swing.

Influence of static lumbar flexion on the trunk muscles' response to sudden arm movements.

BACKGROUND: Viscoelastic creep of lumbar ligaments (prolonged forward bend) has been shown to negatively influence the spine's muscular reflexive behaviour and spinal stability. No studies to date have investigated the influence of spinal viscoelastic creep on the feedforward response of the trunk muscles to sudden arm raises. METHODS: Surface myoelectric activity was collected from the transversus abdominis/internal oblique, the lower erector spinae and the deltoid muscle during sudden ballistic arm raising before and after 10 minutes of prolonged forward bend in 11 healthy participants free of low back injury. The timing of trunk muscle activity relative to the deltoid muscle was calculated for 5 trials before and 5 trials after the creep procedure. RESULTS: Viscoelastic creep had no influence on the feedforward response of the trunk muscles during sudden arm raises. A feedforward response of the trunk muscles was not seen in every study participant and during every trial. CONCLUSION: Passive trunk muscle fatigue does not appear to influence the timing of the stabilizing role of the investigated trunk muscles to sudden arm flexion.

Trunk muscle activity during bridging exercises on and off a Swiss ball.

BACKGROUND: A Swiss ball is often incorporated into trunk strengthening programs for injury rehabilitation and performance conditioning. It is often assumed that the use of a Swiss ball increases trunk muscle activity. The aim of this study was to determine whether the addition of a Swiss ball to trunk bridging exercises influences trunk muscle activity. METHODS: Surface electrodes recorded the myoelectric activity of trunk muscles during bridging exercises. Bridging exercises were performed on the floor as well as on a labile surface (Swiss ball). RESULTS AND DISCUSSION: During the prone bridge the addition of an exercise ball resulted in increased myoelectric activity in the rectus abdominis and external oblique. The internal oblique and erector spinae were not influenced. The addition of a swiss ball during supine bridging did not influence trunk muscle activity for any muscles studied. CONCLUSION: The addition of a Swiss ball is capable of influencing trunk muscle activity in the rectus abdominis and external oblique musculature during prone bridge exercises. Modifying common bridging exercises can influence the amount of trunk muscle activity, suggesting that exercise routines can be designed to maximize or minimize trunk muscle exertion depending on the needs of the exercise population.

The influence of grip width and forearm pronation/supination on upper-body myoelectric activity during the flat bench press.

The myoelectric signal of the sternoclavicular and clavicular portions of the pectoralis major, the biceps brachii, and the lateral head of triceps brachii of 12 healthy men was collected during an isometric hold of 5 different bench press exercises. Grip width (narrow, mid, and wide) and the level of supination/pronation was varied to determine how these factors influence myoelectric amplitude during the flat bench press. A supinated grip resulted in increased activity for the biceps brachii and the clavicular portion of the pectoralis major. Additionally, moving from wide to narrower grip widths increased triceps activity and decreased the sternoclavicular portion of the pectoralis major. However, if the grip was supinated, moving to a narrower grip position did not result in a decrease in muscle activity of the sternoclavicular portion of the pectoralis major. The increase in triceps brachii activity when moving to a narrower grip width was not influenced by the level of supination. Considering the small changes that occur during changes in grip width, the choice of grip position should be determined by the positions athletes adopt during their sport. Sport specificity should supercede attempts to train specific muscle groups.

Replacing a Swiss ball for an exercise bench causes variable changes in trunk muscle activity during upper limb strength exercises.

BACKGROUND: The addition of Swiss balls to conventional exercise programs has recently been adopted. Swiss balls are an unstable surface which may result in an increased need for force output from trunk muscles to provide adequate spinal stability or balance. The aim of the study was to determine whether the addition of a Swiss ball to upper body strength exercises results in consistent increases in trunk muscle activation levels. METHODS: The myoelectric activity of four trunk muscles was quantified during the performance of upper body resistance exercises while seated on both a stable (exercise bench) and labile (swiss ball) surface. Participants performed the supine chest press, shoulder press, lateral raise, biceps curl and overhead triceps extension. A repeated measures ANOVA with post-hoc Tukey test was used to determine the influence of seated surface type on muscle activity for each muscle. RESULTS & DISCUSSION: There was no statistically significant (p < .05) difference in muscle activity between surface conditions. However, there was large degree of variability across subjects suggesting that some individuals respond differently to surface stability. These findings suggest that the incorporation of swiss balls instead of an exercise bench into upper body strength training regimes may not be justified based only on the belief that an increase spinal stabilizing musculature activity is inherent. Biomechanically justified ground based exercises have been researched and should form the basis for spinal stability training as preventative and therapeutic exercise training regimes. CONCLUSION: Selected trunk muscle activity during certain upper limb strength training exercises is not consistently influenced by the replacement of an exercise bench with a swiss ball.

Variations in muscle activation levels during traditional latissimus dorsi weight training exercises: An experimental study.

BACKGROUND: Exercise beliefs abound regarding variations in strength training techniques on muscle activation levels yet little research has validated these ideas. The purpose of the study is to determine muscle activation level, expressed as a percent of a normalization contraction, of the latissimus dorsi, biceps brachii and middle trapezius/rhomboids muscle groups during a series of different exercise tasks. METHODS: The average muscle activity during four tasks; wide grip pulldown, reverse grip pull down [RGP], seated row with retracted scapula, and seated rows with non-retracted scapulae was quantified during two 10 second isometric portions of the four exercises. A repeated measures ANOVA with post-hoc Tukey test was used to determine the influence of exercise type on muscle activity for each muscle. RESULTS & DISCUSSION: No exercise type influenced biceps brachii activity. The highest latissimus dorsi to biceps ratio of activation occurred during the wide grip pulldown and the seated row. Highest levels of myoelectric activity in the middle trapezius/rhomboid muscle group occurred during the seated row. Actively retracting the scapula did not influence middle trapezius/rhomboid activity. CONCLUSION: Variations in latissimus dorsi exercises are capable of producing small changes in the myoelectric activity of the primary movers.

Muscle recruitment patterns during the prone leg extension.

BACKGROUND: The prone leg extension (PLE) is a clinical test used to evaluate the function of the lumbopelvis. It has been theorized that a normal and consistent pattern of muscle activation exists. Previous research has found two contradictory patterns of muscle activation during PLE in normal individuals. One study shows an almost simultaneous activation of the lower erector spinae and hamstring muscle group with a delayed activation of the gluteus maximus, while the second describes the order of activation being ipsilateral erector spinae (to the leg being extended), hamstrings, contralateral erector spinae and gluteus maximus. Due to the different conclusions from these two studies and the lack of quantified muscle onset times, expressed in absolute time this study attempted to quantify the muscle onset times (in milliseconds) during the prone leg extension, while noting if a consistent order of activation exists and whether a timing relationship also exists between the gluteus maximus and contralateral latissimus dorsi. METHODS: 10 asymptomatic males (Average height: 175.2 cm (SD 6.5), Average Weight 75.9 kg (SD 6.5), Average Age: 27.1(SD 1.28)) and 4 asymptomatic females (Average height 164.5 (SD 2.9), weight: 56.2 (SD 8.9), Average Age: 25 (SD 1)) performed the prone leg extension task while the myoelectric signal was recorded from the bilateral lower erector spinae, gluteus maximus and hamstring muscle groups. Activation onsets were determined from the rectified EMG signal relative to the onset of the hamstrings muscle group. RESULTS: No consistent recruitment patterns were detected for prone leg extension among the hamstring muscle group and the erector spinae. However, a consistent delay in the Gluteus Maximus firing of approximately 370 ms after the first muscle activated was found. Five out of 14 asymptomatic subjects showed a delay in gluteus maximus firing exceeding the average delay found in previous research of subjects considered to have a dysfunctional firing pattern. CONCLUSION: A consistent pattern of activation was not found. Variability was seen across subjects. These findings suggest the PLE is not sufficient for a diagnostic test due to the notable physiological variation. An overlap between normal and potentially abnormal activation patterns may exist.

Biomechanical assessments of lumbar spinal function. How low back pain sufferers differ from normals. Implications for outcome measures research. Part I: kinematic assessments of lumbar function.

OBJECTIVE: To review new and advanced biomechanical assessment techniques for the lumbar spine and illustrate the differences in lumbar function in patients with low back pain and asymtomatic subjects. DATA SOURCES: The biomedical literature was searched for research and reviews on spinal kinematic differences between low back pain subjects and healthy controls. A data search for articles indexed on MEDLINE until April 2002 was performed. RESULTS: Kinematic measurements of lumbar function were categorized into 3 areas where low back patients may differ from normals: (1) end range of motion during simple movements; (2) higher order kinematics (displacement, velocity, and acceleration) during complex movement tasks; and (3) spinal proprioception. The assessment of higher order kinematics during complex movement tasks is the most highly researched and the most successful in describing differences between the populations. The use of simple end range of motion appears questionable, while assessing spinal proprioception is the least researched, yet shows potential in highlighting differences between low back sufferers and asymptomatics. CONCLUSION: Current kinematic biomechanical assessment techniques are capable of identifying functional differences between low back pain populations and controls. The use and validity of the majority of these techniques as outcome measures are currently unknown, yet may be valuable in generating functional diagnoses, evaluating the mechanisms of current therapies, and prescribing specific rehabilitation programs.

The use of non-amplitude components of the myoelectric signal in identifying differences in function between the low back injured and controls.

This article primarily reviews the assessment of the non-amplitude dependent components of the myoelectric signal in assessing lumbar function in the low back injured and how persons with low back injuries may differ from the non-injured. Assessment of anomalies in function can loosely be categorized into 4 separate protocols: 1. Assessing the pattern of myoelectric activation, 2. Assessing the EMG frequency spectrum during fatigue, 3. Assessing EMG onset timing during movement and stability challenges and 4. Assessing myoelectric function with link-segment models and EMG assisted spinal models. Assessing the EMG spectrum during fatigue can discriminate between populations; however, questions regarding across day repeatability limit its ability to identify change over time. The remaining techniques are relatively new, show statistically significant differences between the low back injured and normals and provide insight into aberrant spinal stability, motor control function and spinal loading. Their response to rehabilitation programs is largely unknown suggesting a need and avenue for future research.

Clinical considerations in the use of surface electromyography: three experimental studies.

BACKGROUND: The validity and applicability of erector spinae electromyogram (EMG) use in clinical practice is questionable. Differences in the amplitude of the EMG signal between populations with low back pain (LBP) and controls have been hypothesized but not sufficiently documented. OBJECTIVE: To examine issues of EMG asymmetry and repeatability in populations with LBP and populations without LBPin 3 separate studies. STUDY DESIGN: Three separate experimental research studies. METHODS: Study 1 examined the intraclass correlation of the EMG signal of the paraspinal musculature at L3 on 3 separate days during quiet stance with use of 3 different normalization techniques: percent maximum voluntary contraction, percent submaximal voluntary contraction, and percent averaged submaximal contractions. Study 2 used a population with chronic LBP to compare the bilateral asymmetry of paraspinal musculature in segments exhibiting pain with segments not exhibiting pain during quiet stance. A 1-way analysis of variance was used to compare differences between asymmetry scores in the pain and nonpain groups. In study 3, persons with LBP and persons in the control group had the dynamic asymmetry of paraspinal musculature compared during forward bending. A cross-correlation coefficient assessing bilateral muscle activity was calculated for each subject and differences between groups were evaluated using a 1-way analysis of variance. RESULTS: Study 1: Subjects showed excellent repeatability (ICC > 0.75) regardless of the normalization technique. Study 2: During quiet stance no differences were found in bilateral asymmetry between painful and nonpainful motion segments. Study 3: No differences existed in bilateral dynamic symmetry for the upper erector spinae; however, differences between groups did exist for the lower erector spinae. CONCLUSION: Repeatability of the EMG signal during quiet stance is acceptable; however, bilateral asymmetry may not be a definitive indicator of dysfunction.