Lateral Epicondylosis – Pathology & Tissue-Level Interventions +MP3
Research Review By Dr. Brynne Stainsby©
Audio:
Date Posted:
May 2022
Study Title:
Lateral epicondylosis: A literature review to link pathology and tendon function to tissue-level treatment and ergonomic interventions
Authors:
Stegink-Jansen CW, Bynum JG, Lambropoulos AL, Patterson RM & Cowan AC
Author's Affiliations:
Department of Orthopaedic Surgery and Rehabilitation, The University of Texas Medical Branch, Galveston, TX, USA; Department of Occupational Therapy, School of Health Professions, The University of Texas Medical Branch, Galveston, TX, USA; Department of Family and Osteopathic Manipulative Medicine, University of North Texas Health Science Center, Fort Worth, TX, USA.
Publication Information:
Journal of Hand Therapy 2021; 34(2): 263-297.
Background Information:
Lateral epicondylosis (LE) is an upper extremity condition in which patients present with pain at or around the lateral epicondyle, with or without distal radiation. It is a common complaint in workers, athletes and the general population (1-3), with prevalence ranging from 0.7-4.0% in the general population to up to 20% in assembly line workers (4, 5). Given the direct and indirect costs of LE and impact on quality of life, it is important to understand the options for cost-effective care. Surveys demonstrate that patient education regarding activity modification continues to be considered a key intervention by hand therapists, occupational and physical therapists, however, there is a scarcity of information regarding the specific details (6, 7).
The goal of this literature review is to explore and integrate connections between tissue structures, function, environmental and personal factors for the management of patients with LE, using the framework provide by the International Classification of Functioning, Disability and Health (ICF) by the World Health Organization (7). The authors intended to connect the biomechanics and pathology to specific motions during work, sports, and common daily activities to allow therapists, ergonomists, engineers and medical professionals to educate patients on how to adapt activities to reduce the intensity, frequency and duration of exposure to those activities. It should be noted that this study did not intend to be a comprehensive review of the evidence regarding tissue level treatment, rather, to be a brief review of the mechanism of tissue level treatments presented in systematic reviews and randomized controlled trials from 2000 to 2021.
The goal of this literature review is to explore and integrate connections between tissue structures, function, environmental and personal factors for the management of patients with LE, using the framework provide by the International Classification of Functioning, Disability and Health (ICF) by the World Health Organization (7). The authors intended to connect the biomechanics and pathology to specific motions during work, sports, and common daily activities to allow therapists, ergonomists, engineers and medical professionals to educate patients on how to adapt activities to reduce the intensity, frequency and duration of exposure to those activities. It should be noted that this study did not intend to be a comprehensive review of the evidence regarding tissue level treatment, rather, to be a brief review of the mechanism of tissue level treatments presented in systematic reviews and randomized controlled trials from 2000 to 2021.
Summary:
Tissue Involvement:
The normal anatomical architecture of the tissues at the lateral epicondyle is complex. The tendons of the extensor carpi radialis brevis (ECRB) and extensor digitorum communis (EDC) were found to be indistinguishable at the osseotendinous origin in a macroscopic/microscopic study of 40 fresh-frozen cadavers (8). The tendons were free from the underlying aponeurosis, loosely connected to the extensor carpi radialis longus (ECRL) and not embedded in the joint capsule (8). The lateral collateral ligament (LCL) was a distinct structure, deep to the extensor carpi radialis brevis (ECRB) and longus (ECRL). It was noted that the ECRB was particularly vulnerable due to its thin, tendinous nature at the attachment (9). Given the proximity of the ECRB with the EDC, joint capsule and tendon of the supinator, it is assumed that no one structure is solely responsible for lateral elbow pain (8, 10, 11).
The etiology of LE is most commonly considered to be a repetitive strain injury based on population studies, as well as laboratory studies of cyclic loading (12-15). Laboratory studies by Goldie that examined the histopathology of LE concluded that the sub-tendinous tissue played a significant role in LE by comparing tendinous, vascular and neurological tissues obtained intraoperatively from patients with LE to cadaveric tissue from people who had reported no lifetime elbow pain (16). In the operative samples, ECRB hypervascularity was observed and considered to be a sign of healing, as well as unencapsulated nerve endings, which may account for pain with pressure and vibration (16). Connell et al. compared surgically removed tissues and preoperative ultrasound images of patients with LE to images on the uninvolved side and found fibroblastic degeneration, partial tears, and foci of calcification in the involved side, most commonly in ECRB and the EDC (15). Other observed changes included intratendinous calcification, tendon thickening, adjacent bone irregularity, focal hypoechoic regions, and diffuse heterogeneity (11). At the tissue level, pathological changes included increased cellularity, accumulation of ground substance, collagen disorganization and neovascular ingrowth in the lateral elbow complex (17, 18). In comparing biopsies under light microscopy, it appears that there was a shift towards oxidative IIA fibers, possibly due to ischemia (19). MRI studies have identified the involvement of the tendon and enthesis, particularly of the ECRB and EDC (20).
When patients present with bilateral motor deficits, involvement of the central nervous system must be considered (21, 22).
Based on the findings associated with LE pathology, several models of tendinopathy have been proposed. Coombes outlined a model of LE integrating tendon pathology, motor system impairments and pain system changes (18). Fu suggested a linear model of three stages: 1) injury; 2) failed healing; and 3) pathological presentation (23). Cook et al. developed a model based on the relationship between tendon structure, tendon function and pain, which represents a continuum from a non-painful tendon with low functional capacity to painful degenerative tendons. The authors recommend adjusting treatment approaches to the stage and severity of damage and the potential for healing (24).
As indicated above, determining the stage and severity of pathology are important factors in guiding clinical decision making. Severity classification scales have been proposed to guide rehabilitation decisions, such as the validated Patient-Rated Tennis Elbow Evaluation (PRTEE) which includes pain, pain with specific activities, and subsequent disability (25). Advanced imaging such as diagnostic ultrasound or MRI can confirm the diagnosis, however, there is currently a lack of consensus for standard imaging protocol. As is often the case, the structural image does not determine the patient presentation, and the clinical history and physical examination will provide important details regarding function and/or disability.
The normal anatomical architecture of the tissues at the lateral epicondyle is complex. The tendons of the extensor carpi radialis brevis (ECRB) and extensor digitorum communis (EDC) were found to be indistinguishable at the osseotendinous origin in a macroscopic/microscopic study of 40 fresh-frozen cadavers (8). The tendons were free from the underlying aponeurosis, loosely connected to the extensor carpi radialis longus (ECRL) and not embedded in the joint capsule (8). The lateral collateral ligament (LCL) was a distinct structure, deep to the extensor carpi radialis brevis (ECRB) and longus (ECRL). It was noted that the ECRB was particularly vulnerable due to its thin, tendinous nature at the attachment (9). Given the proximity of the ECRB with the EDC, joint capsule and tendon of the supinator, it is assumed that no one structure is solely responsible for lateral elbow pain (8, 10, 11).
The etiology of LE is most commonly considered to be a repetitive strain injury based on population studies, as well as laboratory studies of cyclic loading (12-15). Laboratory studies by Goldie that examined the histopathology of LE concluded that the sub-tendinous tissue played a significant role in LE by comparing tendinous, vascular and neurological tissues obtained intraoperatively from patients with LE to cadaveric tissue from people who had reported no lifetime elbow pain (16). In the operative samples, ECRB hypervascularity was observed and considered to be a sign of healing, as well as unencapsulated nerve endings, which may account for pain with pressure and vibration (16). Connell et al. compared surgically removed tissues and preoperative ultrasound images of patients with LE to images on the uninvolved side and found fibroblastic degeneration, partial tears, and foci of calcification in the involved side, most commonly in ECRB and the EDC (15). Other observed changes included intratendinous calcification, tendon thickening, adjacent bone irregularity, focal hypoechoic regions, and diffuse heterogeneity (11). At the tissue level, pathological changes included increased cellularity, accumulation of ground substance, collagen disorganization and neovascular ingrowth in the lateral elbow complex (17, 18). In comparing biopsies under light microscopy, it appears that there was a shift towards oxidative IIA fibers, possibly due to ischemia (19). MRI studies have identified the involvement of the tendon and enthesis, particularly of the ECRB and EDC (20).
When patients present with bilateral motor deficits, involvement of the central nervous system must be considered (21, 22).
Based on the findings associated with LE pathology, several models of tendinopathy have been proposed. Coombes outlined a model of LE integrating tendon pathology, motor system impairments and pain system changes (18). Fu suggested a linear model of three stages: 1) injury; 2) failed healing; and 3) pathological presentation (23). Cook et al. developed a model based on the relationship between tendon structure, tendon function and pain, which represents a continuum from a non-painful tendon with low functional capacity to painful degenerative tendons. The authors recommend adjusting treatment approaches to the stage and severity of damage and the potential for healing (24).
As indicated above, determining the stage and severity of pathology are important factors in guiding clinical decision making. Severity classification scales have been proposed to guide rehabilitation decisions, such as the validated Patient-Rated Tennis Elbow Evaluation (PRTEE) which includes pain, pain with specific activities, and subsequent disability (25). Advanced imaging such as diagnostic ultrasound or MRI can confirm the diagnosis, however, there is currently a lack of consensus for standard imaging protocol. As is often the case, the structural image does not determine the patient presentation, and the clinical history and physical examination will provide important details regarding function and/or disability.
Tissue Involvement: Healing Models
Proof of principle studies examine mechanisms of tissue healing, such as promoting protein synthesis in fibroblasts (26-28), managing vascularity (28-30), transforming collagen structure (31), changing gamma tone of muscle (32), better aligning connective tissue fibrils (27, 33, 34), modulating nociceptive impulses (35), enhancing extracellular matrix modification (36) and neuromodulation (28). Treatments aim to unload tissues, such as altering the line of force production applied to the tendinous structure or reducing force production or resting involved tissues by partial or full immobilization. Eight systematic reviews were found for commonly used modalities to treat patients with LE, including therapeutic ultrasound, transcutaneous electrical nerve stimulation (TENS), extracorporeal shock wave therapy (ESWT), low-level laser therapy (LLLT), targeted exercises, dry needling, myofascial release, friction massage, acupuncture, counterforce braces, and wrist orthoses.
In contrast, clinical outcome studies evaluate patient responses to reflect the load capacity of the tendon. In a review of 20 randomized trials and two systematic reviews of electrophysiological modalities, there was moderate evidence to support the use of ultrasound and ultrasound plus friction massage for improving pain, and moderate evidence to support the use of LLLT to improve pain and grip strength (37). There was limited or conflicting evidence to support the use of electrical stimulation, TENS, ESWT, acupuncture, dry needling, myosfascial release, and deep friction massage (37).
Interventions intend to alter or decrease the load on impacted tissues, based on the hypothesis that loading a painful tendon perpetuates nociceptive stimuli and that the resultant hyperalgesia is a response to the ongoing nociception (38). However, studies of counterforce bracing have not demonstrated improved pain tolerance when compared with physical therapy, wrist orthoses and LLLT (34, 35).
Wrist and forearm orthoses are intended to limit force production by the extensor muscles, shorten the arc of muscle pull and decrease force load of the tendons (36, 39). While no consensus exists regarding the optimal design of an orthosis, it appears that use significantly improved grip strength, however, did not significantly reduce pain (40).
Studies of targeted exercises typically aim to reduce pain and/or enhance load capacity and function of the affected tendons. Eccentric exercise protocols have demonstrated improvement in pain and function; however, further research is required to determine long-term effects (41-44). Moderate evidence also exists to support the use of stretching and strengthening exercises to improve pain, as well as cervical and thoracic manipulation combined with concentric, eccentric, and wrist mobilization exercises to improve grip strength (45).
Proof of principle studies examine mechanisms of tissue healing, such as promoting protein synthesis in fibroblasts (26-28), managing vascularity (28-30), transforming collagen structure (31), changing gamma tone of muscle (32), better aligning connective tissue fibrils (27, 33, 34), modulating nociceptive impulses (35), enhancing extracellular matrix modification (36) and neuromodulation (28). Treatments aim to unload tissues, such as altering the line of force production applied to the tendinous structure or reducing force production or resting involved tissues by partial or full immobilization. Eight systematic reviews were found for commonly used modalities to treat patients with LE, including therapeutic ultrasound, transcutaneous electrical nerve stimulation (TENS), extracorporeal shock wave therapy (ESWT), low-level laser therapy (LLLT), targeted exercises, dry needling, myofascial release, friction massage, acupuncture, counterforce braces, and wrist orthoses.
In contrast, clinical outcome studies evaluate patient responses to reflect the load capacity of the tendon. In a review of 20 randomized trials and two systematic reviews of electrophysiological modalities, there was moderate evidence to support the use of ultrasound and ultrasound plus friction massage for improving pain, and moderate evidence to support the use of LLLT to improve pain and grip strength (37). There was limited or conflicting evidence to support the use of electrical stimulation, TENS, ESWT, acupuncture, dry needling, myosfascial release, and deep friction massage (37).
Interventions intend to alter or decrease the load on impacted tissues, based on the hypothesis that loading a painful tendon perpetuates nociceptive stimuli and that the resultant hyperalgesia is a response to the ongoing nociception (38). However, studies of counterforce bracing have not demonstrated improved pain tolerance when compared with physical therapy, wrist orthoses and LLLT (34, 35).
Wrist and forearm orthoses are intended to limit force production by the extensor muscles, shorten the arc of muscle pull and decrease force load of the tendons (36, 39). While no consensus exists regarding the optimal design of an orthosis, it appears that use significantly improved grip strength, however, did not significantly reduce pain (40).
Studies of targeted exercises typically aim to reduce pain and/or enhance load capacity and function of the affected tendons. Eccentric exercise protocols have demonstrated improvement in pain and function; however, further research is required to determine long-term effects (41-44). Moderate evidence also exists to support the use of stretching and strengthening exercises to improve pain, as well as cervical and thoracic manipulation combined with concentric, eccentric, and wrist mobilization exercises to improve grip strength (45).
Biomechanical findings, population findings and ergonomic interventions:
Understanding anatomical and biomechanical principles of muscle and tendon behaviours are critical to understanding the movements that may place an individual at risk for the development of recurrent LE. The function of a tendon is to transfer tensile forces produced by the muscle to the appropriate target, as well as absorb stress and shock due to their viscoelastic behaviour (38, 39, 46, 47).
Tendons are vulnerable to injury in several forms. They may experience perpendicular compression by overlying tissues and may experience shearing forces at bony prominences. They are also subject to strain (passive elongation) and stress (applied load). It is noted that the highest load will be placed on a tendon when a muscular contraction is applied to a maximally elongated tendon. In this way, it is an important concept to allow full recovery to the resting position in order to best transfer forces and avoid injury.
With respect to LE specifically, the ECRB has more force generating potential (able to generate larger forces at higher velocities) than the ECRL, however, ECRL’s longer fibers allow for force production over a large trajectory of motion (48). It is also noted that as the ECRB does not cross the elbow joint, it is not affected by elbow position and all of its force capacity is applied to wrist extension. The ECRL attaches approximately 4-5 cm proximal to the lateral epicondyle, along the lateral supracondylar ridge. The ECRL tendon is most superficial anatomically, thus rendering it less vulnerable to compression or shear due to bony prominences. While these two muscles can work synergistically, the ECRB is more vulnerable when compared with the ECRL based on its location and force production patterns.
Many studies have examined the interactions of active and passives forces at the lateral elbow to determine the impact of excessive strain, compression, shearing and tension on tissue vulnerability and damage. In a study of the anatomy of 139 cadaveric limbs, ECRB lengthening was found to be most marked with the forearm in full pronation and the wrist in flexion and ulnar deviation (49). In a study of 60 cadavers, the tendon of the ECRB was found to be vulnerable to compression because it was located adjacent to the capitellum and covered by the EDC, as well as sections of the ECRL (50). With increasing elbow extension, the stretch of the ECRL created increased compression of the underlying ECRB. The underside of the extensor tendon complex was also vulnerable to cumulative abrasion through lateral displacement of the tendon and the rubbing of the ECRB against the capitellum and against the radial head through the final 30° of extension. A follow-up study of eight fresh cadavers investigated the contact pressure under the ECRL, ECRB and EDC against the capitellum. The highest contact pressure was measured with the fully extended elbow in the pronated position (51). These findings form the basis of diagnostic tests such as Cozen’s or Mills (52, 53). Further research is also required to examine the effect that more proximal muscles in the kinetic chain have on LE.
Understanding anatomical and biomechanical principles of muscle and tendon behaviours are critical to understanding the movements that may place an individual at risk for the development of recurrent LE. The function of a tendon is to transfer tensile forces produced by the muscle to the appropriate target, as well as absorb stress and shock due to their viscoelastic behaviour (38, 39, 46, 47).
Tendons are vulnerable to injury in several forms. They may experience perpendicular compression by overlying tissues and may experience shearing forces at bony prominences. They are also subject to strain (passive elongation) and stress (applied load). It is noted that the highest load will be placed on a tendon when a muscular contraction is applied to a maximally elongated tendon. In this way, it is an important concept to allow full recovery to the resting position in order to best transfer forces and avoid injury.
With respect to LE specifically, the ECRB has more force generating potential (able to generate larger forces at higher velocities) than the ECRL, however, ECRL’s longer fibers allow for force production over a large trajectory of motion (48). It is also noted that as the ECRB does not cross the elbow joint, it is not affected by elbow position and all of its force capacity is applied to wrist extension. The ECRL attaches approximately 4-5 cm proximal to the lateral epicondyle, along the lateral supracondylar ridge. The ECRL tendon is most superficial anatomically, thus rendering it less vulnerable to compression or shear due to bony prominences. While these two muscles can work synergistically, the ECRB is more vulnerable when compared with the ECRL based on its location and force production patterns.
Many studies have examined the interactions of active and passives forces at the lateral elbow to determine the impact of excessive strain, compression, shearing and tension on tissue vulnerability and damage. In a study of the anatomy of 139 cadaveric limbs, ECRB lengthening was found to be most marked with the forearm in full pronation and the wrist in flexion and ulnar deviation (49). In a study of 60 cadavers, the tendon of the ECRB was found to be vulnerable to compression because it was located adjacent to the capitellum and covered by the EDC, as well as sections of the ECRL (50). With increasing elbow extension, the stretch of the ECRL created increased compression of the underlying ECRB. The underside of the extensor tendon complex was also vulnerable to cumulative abrasion through lateral displacement of the tendon and the rubbing of the ECRB against the capitellum and against the radial head through the final 30° of extension. A follow-up study of eight fresh cadavers investigated the contact pressure under the ECRL, ECRB and EDC against the capitellum. The highest contact pressure was measured with the fully extended elbow in the pronated position (51). These findings form the basis of diagnostic tests such as Cozen’s or Mills (52, 53). Further research is also required to examine the effect that more proximal muscles in the kinetic chain have on LE.
Exposure Hazards:
The following exposures were noted to affect the upper limbs: intense exertions, long-duration exertion, eccentric or lengthening contractions, sudden or ballistic exertions, high angular velocities, friction and the force of muscular contractions (including static contractions), lack of muscular rest, and non-neutral wrist positions. Additionally, hazardous activities included vibration, use of gloves, localized compression and cold (< 45°F) (54, 55).
The following exposures were noted to affect LE specifically: combining repeated forceful work in a non-neutral posture of the hand/arm, higher percentage of time spent in < 45° of supination or pronation, combining supination and forceful lifting, high wrist angular velocity, wrist flexion, repetitive flexion/extension of the elbow, reaching, eccentric contraction of wrist extensor muscles, combination of high physical exertion and elbow flexion/extension, and high grip forces. Activity-focused hazardous exposures specific to LE were: handling of tools and loads in overhead positions, working with vibrating tools, and awkward limb postures.
Personal factors may also play an important role in the prevention, onset, or rehabilitation of repetitive strain injuries. Such personal factors include age between 36-50, being female and/or being a smoker (56). Low social support also increased the odds for developing LE, while high social support provided a protective influence. Workers with LE were also found to have less work satisfaction than those without. Women with LE in particular were more likely to report lower job autonomy and less contact with colleagues compared to matched controls (57). In a cross-sectional study of 1824 participants found an association between LE and personal factors (58). Organizational factors such as time pressure and low decision latitude were also found to be occupational ergonomic stressors (59).
To measure risk and outcomes, measurement of exposure to hazardous activities is important. Data can be collected through physical examinations, general health questionnaires, work-related questionnaires, plant walk-throughs, work observations, and social support scales. Relevant outcomes measures include the Hand Activity Level (60, 61), the Composite Strain Index, the Cumulative Strain Index and the Strain Index/Revised Strain Index (62-65).
The following exposures were noted to affect the upper limbs: intense exertions, long-duration exertion, eccentric or lengthening contractions, sudden or ballistic exertions, high angular velocities, friction and the force of muscular contractions (including static contractions), lack of muscular rest, and non-neutral wrist positions. Additionally, hazardous activities included vibration, use of gloves, localized compression and cold (< 45°F) (54, 55).
The following exposures were noted to affect LE specifically: combining repeated forceful work in a non-neutral posture of the hand/arm, higher percentage of time spent in < 45° of supination or pronation, combining supination and forceful lifting, high wrist angular velocity, wrist flexion, repetitive flexion/extension of the elbow, reaching, eccentric contraction of wrist extensor muscles, combination of high physical exertion and elbow flexion/extension, and high grip forces. Activity-focused hazardous exposures specific to LE were: handling of tools and loads in overhead positions, working with vibrating tools, and awkward limb postures.
Personal factors may also play an important role in the prevention, onset, or rehabilitation of repetitive strain injuries. Such personal factors include age between 36-50, being female and/or being a smoker (56). Low social support also increased the odds for developing LE, while high social support provided a protective influence. Workers with LE were also found to have less work satisfaction than those without. Women with LE in particular were more likely to report lower job autonomy and less contact with colleagues compared to matched controls (57). In a cross-sectional study of 1824 participants found an association between LE and personal factors (58). Organizational factors such as time pressure and low decision latitude were also found to be occupational ergonomic stressors (59).
To measure risk and outcomes, measurement of exposure to hazardous activities is important. Data can be collected through physical examinations, general health questionnaires, work-related questionnaires, plant walk-throughs, work observations, and social support scales. Relevant outcomes measures include the Hand Activity Level (60, 61), the Composite Strain Index, the Cumulative Strain Index and the Strain Index/Revised Strain Index (62-65).
Ergonomic Interventions:
One of the key objectives in ergonomic design is to organize and design activities such that muscles and joints are placed in a neutral position. For the upper extremity, 90° of elbow flexion eliminates compression of the ECRL on the ECRB, and risks are lessened starting at 30° of elbow flexion. Due to the varied scenarios of developing LE, there is not currently adequate evidence to substantiate the benefits of ergonomic interventions. With that said, Koningsveld recommended the following process when considering the implementation of ergonomic interventions: 1) inventory the problems; 2) worker participation; 3) management support; 4) step-by-step approach; 5) expand focus beyond health issues; 6) establish a steering group; 7) check program effects; and 8) check the cost/benefit ratio (63).
Clinical Application & Conclusions:
This review synthesized the models of pathology, the models of healing, and the interventions that may provide benefits such as decreased pain, improved grip strength and function. The authors also provided an overview of outcome measures and diagnostic tests that can be used to diagnose and monitor LE.
While it is possible that exercise protocols may improve tissue healing, tissue-based interventions have not been well studied based on the stage and severity of disease. Further research is needed to study the role of localized and/or full kinetic chain exercise. While eccentric wrist extension exercises are commonly used clinically, more research is needed to examine the long-term results of this approach (64).
Based on the biomechanical and population-based studies included in the current review, it may be helpful for clinicians to encourage patients to consider reducing force, compression, and shear at the LE in order to reduce symptoms. It is unclear whether patients/workers/athletes can accurately estimate a dosage of exposure experienced during a day or work cycle and future research is needed to estimate exposure to harm.
This review also highlights the need for improved specification for ergonomic interventions, as well as the role of environmental context in assessment of risk. Collaboration between health care providers and engineering professionals may provide meaningful insights into the assessment of repetitive motion injuries. Overall, clinicians should use their current knowledge of biomechanical and population-based risk factors to guide patients to formulate a personal inventory of tissue-oriented risk factors in order to minimize risk of developing LE.
While it is possible that exercise protocols may improve tissue healing, tissue-based interventions have not been well studied based on the stage and severity of disease. Further research is needed to study the role of localized and/or full kinetic chain exercise. While eccentric wrist extension exercises are commonly used clinically, more research is needed to examine the long-term results of this approach (64).
Based on the biomechanical and population-based studies included in the current review, it may be helpful for clinicians to encourage patients to consider reducing force, compression, and shear at the LE in order to reduce symptoms. It is unclear whether patients/workers/athletes can accurately estimate a dosage of exposure experienced during a day or work cycle and future research is needed to estimate exposure to harm.
This review also highlights the need for improved specification for ergonomic interventions, as well as the role of environmental context in assessment of risk. Collaboration between health care providers and engineering professionals may provide meaningful insights into the assessment of repetitive motion injuries. Overall, clinicians should use their current knowledge of biomechanical and population-based risk factors to guide patients to formulate a personal inventory of tissue-oriented risk factors in order to minimize risk of developing LE.
Study Methods:
- An explorative literature search was performed first to identify key constructs/keywords and inform the eventual literature search. Given the sparsity of systemic reviews, the authors decided to use the framework for behaviour intervention development by the National Institute of Health (65) to synthesize ergonomic interventions for patients with LE.
- The following constructs were identified and used as keywords: lateral epicondylosis, lateral epicondylitis, lateral epicondylalgia, tennis elbow, ECRB, incidence and prevalence, recovery and natural course, at-risk populations and occupations, work-related, sports, performing artists, anatomy, biomechanics and kinematics, neurosensory coordination, assessment and examination including imaging, ergonomics, adaptation, prevention, psychology, roles of occupational therapists and physical therapists in industry, ergonomics, participatory ergonomic programs, and review articles including history.
- Data collection tables were created that included study purpose, study design and methods, study sample, intervention or exposures, type of measurement and results or outcomes.
Study Strengths / Weaknesses:
Strengths:
This study provided an overview of the mechanism of tissue-level treatments and provided context for many of the commonly used clinical approaches. It was a helpful summary of the anatomy and physiology of the tissues at the lateral epicondyle.
This study provided an overview of the mechanism of tissue-level treatments and provided context for many of the commonly used clinical approaches. It was a helpful summary of the anatomy and physiology of the tissues at the lateral epicondyle.
Weaknesses:
It is important to note that this study was based on an explorative literature review and is not a systematic review. Based on a review of the provided methodology, it is not possible to ascertain the quality of the search strategy or if/how the included studies were critically appraised, and thus the results must be interpreted through that lens. The authors acknowledge that this paper is not intended to be a comprehensive review of the literature. As such, a more thorough discussion on the weaknesses of this paper would not be particularly productive, rather, it is suggested that readers use this paper as the overview it was intended to be.
It is important to note that this study was based on an explorative literature review and is not a systematic review. Based on a review of the provided methodology, it is not possible to ascertain the quality of the search strategy or if/how the included studies were critically appraised, and thus the results must be interpreted through that lens. The authors acknowledge that this paper is not intended to be a comprehensive review of the literature. As such, a more thorough discussion on the weaknesses of this paper would not be particularly productive, rather, it is suggested that readers use this paper as the overview it was intended to be.
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