Development Of Cumulative Trauma Disorders Research Articles

Psychosocial influences in the development of cumulative trauma disorders

Study DesignThis study is a single-phase, qualitative study using grounded theory methodology. IntroductionCumulative trauma disorders (CTDs) are musculoskeletal disorders that impact health and productivity. CTD risk factors are present in the workplace, home, and community. Occupational and physical therapists specializing in hand and upper extremity rehabilitation (hand therapists) are widely involved with this population. Hand therapists often employ a medical model in the assessment and treatment of these conditions; however, the medical model has not proven to be consistently effective in relieving symptoms or producing a durable return to daily living activities. Purpose of the StudyThe purpose of this study was to explore the lived experiences of individuals diagnosed with CTD, and investigate the psychosocial phenomena influencing CTD development as an impediment to occupational performance. MethodsThe principal investigator recruited 11 participants who met specific inclusion criteria, then used semi-structured interviews aimed at exploring the lived experiences of the participants while investigating the psychosocial phenomenon influencing CTD development. Interviews were transcribed and analyzed using a process of constant comparison, up until saturation occurred. Trustworthiness techniques were used in the data analysis phase and included peer reviews and member checking. FindingsThe findings suggest that many psychosocial factors contribute to the development and impact of CTDs, at both onset of symptoms and throughout the duration of the condition. A significant number of contextual factors influence participants’ function, behavior, relationships, and the course of medical care. Themes derived from the participants’ expressions, included the following: 1) an initial strategy of “work through the pain,” can be detrimental to symptom resolution and leads to progressive failure to meet role expectations, 2) a pervasive notion of CTDs as “an invisible disability,” leaving participants feeling isolated and frustrated when significant others fail to offer support or reject them, 3) participants often delayed reporting symptom development to employers, family members, and medical personnel, risking permanent injury and disability, 4) a “stigma” is attached to CTDs that encourages isolation; however, the social support of even one significant other in a person's life can facilitate adaptation. Discussion and ConclusionAll participants experienced hardship because of their conditions; however, two of the eleven participants capably navigated the process, using past experience and support from family and employer to successfully adapt. These findings offer support that CTDs are adaptive disorders. The study's conclusion suggests a new model to describe CTD dysfunction and presents new ways of thinking for clinicians who treat the CTD population.

Psychosocial Influences in the Development of Cumulative Trauma Disorders

ABSTRACT Study Design This study is a single-phase, qualitative study using grounded theory methodology. Introduction Cumulative trauma disorders (CTDs) are musculoskeletal disorders that impact health and productivity. CTD risk factors are present in the workplace, home, and community. Occupational and physical therapists specializing in hand and upper extremity rehabilitation (hand therapists) are widely involved with this population. Hand therapists often employ a medical model in the assessment and treatment of these conditions; however, the medical model has not proven to be consistently effective in relieving symptoms or producing a durable return to daily living activities. Purpose of the Study The purpose of this study was to explore the lived experiences of individuals diagnosed with CTD, and investigate the psychosocial phenomena influencing CTD development as an impediment to occupational performance. Methods The principal investigator recruited 11 participants who met specific inclusion criteria, then used semi-structured interviews aimed at exploring the lived experiences of the participants while investigating the psychosocial phenomenon influencing CTD development. Interviews were transcribed and analyzed using a process of constant comparison, up until saturation occurred. Trustworthiness techniques were used in the data analysis phase and included peer reviews and member checking. Findings The findings suggest that many psychosocial factors contribute to the development and impact of CTDs, at both onset of symptoms and throughout the duration of the condition. A significant number of contextual factors influence participants’ function, behavior, relationships, and the course of medical care. Themes derived from the participants’ expressions, included the following: 1) an initial strategy of “work through the pain,” can be detrimental to symptom resolution and leads to progressive failure to meet role expectations, 2) a pervasive notion of CTDs as “an invisible disability,” leaving participants feeling isolated and frustrated when significant others fail to offer support or reject them, 3) participants often delayed reporting symptom development to employers, family members, and medical personnel, risking permanent injury and disability, 4) a “stigma” is attached to CTDs that encourages isolation; however, the social support of even one significant other in a person's life can facilitate adaptation. Discussion and Conclusion All participants experienced hardship because of their conditions; however, two of the eleven participants capably navigated the process, using past experience and support from family and employer to successfully adapt. These findings offer support that CTDs are adaptive disorders. The study's conclusion suggests a new model to describe CTD dysfunction and presents new ways of thinking for clinicians who treat the CTD population.

Ergonomic evaluation of cumulative trauma disorders among female carpet weavers in India: guidelines to an effective sustainability in work system design

The development of cumulative trauma disorders (CTD) is the most common problem among weavers in hand-woven carpet industry. The main idea of this paper is shedding light on the problems encountered during hand weaving and establishes the guidelines to develop ergonomically efficient workstation for carpet weaving. Seventy-nine randomly selected female weavers were surveyed and the data about pain occurring in body regions were collected by questionnaire. Strain Index (SI) technique was used to identify the postural risks. Grip strength tests were conducted to assess the change in static muscle strength during weaving. Most of the participants reported discomfort in different body and palmar regions. There was a significant difference between the physical and physiological factors before and after weaving (p < 0.05). SI priority scores revealed that the working posture during weaving requires necessary action. As the main outcomes, recommended guidelines may help in designing ergonomically efficient work system to prevent CTDs among weavers.

Usability Validation of an Ergonomic Inward Directional Screwdriver for Enhanced Musculoskeletal Comfort

Previous studies suggested that the use of inward torque direction in hand-related manual activities not only increases the total normal force and torque capacity but also reduces grip force. This means lesser effort is required to perform the task, which prevents overexertion and hand injuries. Manual screwdrivers are the most common hand tools used in the industry and daily life. However, due to the difficulty users face when unfastening screws, it can also be a hand tool that potentially leads to the development of cumulative trauma disorders. In this study, 50 subjects participated in a psychophysical testing of an ergonomic inward directional screwdriver and a normal manual screwdriver. The comparative study involved the perceptions of grip, comfort and ease-of-twist for both normal and ergonomic manual screwdrivers. The data was analysed using the analysis of variance via Minitab 16. The results showed that grip, comfort and ease-of-twist are significantly affected by torque direction and ergonomics features. Further observations on participant justifications also suggested that participants rated the inward screwdriver as a better tool to be used compared to the normal screwdriver.

Standard Deviation of sEMG

Certain muscle activities (e.g. static muscle activities for prolonged periods of time) and resultant movement patterns may be associated with the development of cumulative trauma disorders. Currently, there is no simple, well-defined measure to discern if a muscle is performing a static or dynamic activity. In this paper, we present the results of a simple study designed to investigate whether the standard deviation (SD) of sEMG is an effective method of identifying muscle dynamicity. Participants completed two separate tasks with a desktop touchscreen device—one requiring static muscle movements and the other to elicit dynamic movements while we measured muscle activity. The SD was more was more varied (M = 4.8 ±.4% MVC) during the dynamic task compared to the Static task (M = 2.5 ±0.2% MVC). Participants’ muscles had a lower Mean (exertion) (M = 7.3 ± 0.8% MVC) in the dynamic task compared to the Static task (M = 11.6 ±1.1% MVC). This interaction of measure and task was significant, F(1,18) = 72.23, p &lt; .001, η2 = 0.80. Thus standard deviation of sEMG was found to be a valid measure of muscle dynamicity.

Children computer mouse use and anthropometry

Studies have shown that increased computer use among adults in occupational settings is associated with the development of cumulative trauma disorders; however, the need to address how adult-sized mice and keyboards are affecting children is becoming increasingly important as both access to and use of computers is increasing among today's youth. To address the potential mismatch that exists between child stature and computer input device size and activation force, we have applied existing, age-specific, anthropometric data to elements of device design, including mouse size (length, width, height, switch location), and mouse-button activation forces. Trends supported the development of smaller computer input devices with lower activation forces for smaller statured individuals including children. Distinct and consistent trends in size delineations were seen across gender and age groups-trends that correlate well with grades and schooling in the United States education system . Three to four mouse sizes would be recommended: a mouse sized for adult and high school males; one for adult and high school females and junior high males; one for elementary school children, aged 6 to 10 years; and possibly a mouse for the smallest users who are less than six years old.

Tendon and nerve excursion in the carpal tunnel in healthy and CTD wrists

BackgroundDuring hand and finger motions, friction between flexor digitorum superficialis tendon and the median nerve is thought to play a role in the development of cumulative trauma disorders. This study investigated three methods to determine excursions of the flexor digitorum superficialis tendon and median nerve using several motions. MethodsTwenty-five participants (mean age 37.2years SD 13.4) were classified as healthy (n=16), self-reported distal upper extremity cumulative trauma disorders (6), or wheelchair users (3). Static carpal tunnel measurements were taken and displacements of the index flexor digitorum superficialis tendon and median nerve were determined via the velocity time integral and post hoc integration of the Doppler ultrasound waveform using a 12–5MHz linear array transducer, as well as using predictive equations. FindingsMedian nerves in symptomatic wrists were larger than healthy wrists by 4.2mm2 (left) and 4.1mm2 (right) proximally to less than 1.4mm2 distally. In healthy wrists, left–right tendon excursion differences ranged from 0.7mm to 4.3mm depending on the motion while left to right differences in symptomatic wrists ranged over 22.2mm. Ultrasound measures of tendon excursion overestimated those determined using predictive equations and were poorly correlated.The ratio of median nerve excursion to tendon excursion was lower in finger only motions compared to wrist motions with or without finger motion. InterpretationSpectral Doppler ultrasound imaging provided insights into tendon excursion that was not apparent with mathematical modeling. The difference in excursion between finger motions and wrist motions could be beneficial in therapeutic techniques.

The Effects of Gender Discrimination on Refugee Torture Survivors: A Cross-Cultural Traumatology Perspective

Trauma developmental theory identifies gender discrimination (GD) as a type of persistent, ongoing trauma that has the potential for serious, negative effects on mental health. This study was conducted to examine the potential role of GD in the development of cumulative trauma disorders (CTD) and symptoms of posttraumatic stress disorder (PTSD) as well as the role of GD in mediating the effects of other traumas on these disorders. The sample included 160 female torture survivors from more than 30 countries. Measures of PTSD, CTD, and types of trauma exposure were acquired as part of a larger study on refugee torture survivors. Structural equation modeling was used to test several plausible models for the direct and indirect effects of GD on PTSD and CTD, within the context of other trauma exposure. Results suggest that GD mediates the effects of identity traumas on CTD and PTSD. GD also had direct effects on CTD, including relationships with dissociation, suicidality, and deficits in executive function. GD did not appear to directly influence the development of PTSD. The implications of these results for assessment and treatment of women's trauma-related disorders as well as strategies for their prevention are discussed.

Exposição ocupacional do cirurgião-dentista à vibração mecânica transmitida através das mãos: um estudo de caso

O objetivo do presente trabalho foi estimar a exposição a vibrações induzidas pelo uso de instrumentos rotatórios por cirurgiões-dentistas. Os instrumentos rotatórios analisados foram de alta e de baixa rotação. Os efeitos deletérios das vibrações no conjunto mão/braço são uma função da frequência e da amplitude do sinal. Observou-se que os efeitos dependem, ainda, da excitação ser constituída por uma única frequência ou apresentar um espectro complexo. Foram testadas três amostras de cada instrumento rotatório (canetas), a saber: caneta de alta rotação, contra-ângulo de baixa rotação e peça de mão, também de baixa rotação. A utilização por cirurgiões-dentistas dos instrumentos rotatórios avaliados aqui não representa risco ocupacional em termos das vibrações transmitidas às mãos, mesmo que operados continuamente ao longo de seis horas de trabalho; entretanto pode ser importante fator coadjuvante no desenvolvimento de LERs/DORTs. Por outro lado, o conjunto de efeitos fisiológicos das vibrações leva a crer que fortes oscilações mecânicas diminuem a capacidade de desempenho e em muitas situações aumentam o risco de falhas e acidentes.

Repetitive Motion in Perception of Tactile Sensation in the Fingers of String Players

Little is known about the mechanisms that underlie the pathophysiology involved in the development of cumulative trauma disorders. Musicians, specifically string players, may be a useful model to examine the cumulative effects of repetitive motion given the highly attended movements of their left hands and the stereotypical grasp of their right hands. Musculoskeletal disorders related to playing are experienced by 39% to 87% of musicians, making musicians a potentially good model for the study of factors involved in development of cumulative trauma disorders. Sensory thresholds for two-point discrimination and light touch were measured in all phalanges of each digit, of each hand. Comparisons were made within and between a control group of 10 nonmusicians who did not engage in repetitive motion and 10 healthy musicians who did. There were 5 violinists, 2 violists, and 3 cellists. The Non-musician group perceived two-points and light touch at significantly lower thresholds in the proximal phalanges of the left hand than the right hand. Significant differences were not present between right and left hands for the means of distal, middle, and proximal phalanges of the Musician group. This lack of significant difference may be due to higher sensory thresholds associated with repetitive use of the left hand of the musicians.

Muscular dysfunction elicited by creep of lumbar viscoelastic tissue

The biomechanics, histology and electromyography of the lumbar viscoelastic tissues and multifidus muscles of the in vivo feline were investigated during 20 min of static as well as cyclic flexion under load control and during 7 h of rest following the flexion. It was shown that the creep developed in the viscoelastic tissues during the 20 min of static or cyclic flexion did not fully recover over the 7 h of following rest. It was further seen that a neuromuscular disorder with five distinct components developed during and after the static and cyclic flexion. The neuromuscular disorder consisted of a decreasing magnitude of reflexive EMG from the multifidus upon flexion as well as of superimposed spasms. The recovery period was characterized by an initial muscle hyperexcitability, a slowly increasing reflexive EMG and a delayed hyperexcitability. Histological data from the supraspinous ligament demonstrate significant increase (× 10) in neutrophil density in the ligament 2 h into the recovery and even larger increase (×100) 6 h into the recovery from the 20 min flexion, indicating an acute soft tissue inflammation. It was concluded that sustained static or cyclic loading of lumbar viscoelastic tissues may cause micro-damage in the collagen structure, which in turn reflexively elicit spasms in the multifidus as well as hyperexcitability early in the recovery when the majority of the creep recovers. The micro-damage, however, results in the time dependent development of inflammation. In all cases, the spasms, initial and delayed hyperexcitabilities represent increased muscular forces applied across the intervertebral joints in an attempt to limit the range of motion and unload the viscoelastic tissues in order to prevent further damage and to promote healing. It is suggested that a significant insight is gained as to the development and implications of a common idiopathic low back disorder as well as to the development of cumulative trauma disorders.

Key Elements of an Ergonomics Process: Developing Surveillance Tools to Evaluate Risk Factors

Risk is defined as the exposure to the chance of injury or loss. Developing models or methods to evaluate the level of risk for a particular exposure comes from controlled experimentation. Cumulative trauma disorders are one type of loss that contributes to significant pain and suffering for people and for the industry in which these people work. However, no simple model exists which show how physical risk factors may contribute to the development of cumulative trauma disorders. This paper concentrates on efforts to evaluate ergonomic risk and associated outcomes on manufacturing and assembly jobs using existing ergonomic assessment tools to accurately assess risk. This paper concentrates on preliminary results as it relates to the upper extremity.

Cumulative trauma disorders and keyboarding work

This paper reviews the current state of the relationship between computer keyboard use and the development of cumulative trauma disorders [CTDs] as found in the literature. Alternative keyboard designs using biomechanical evaluation methods as justification for their use are also reviewed. Critical factors such as the repetitiveness of the keyboarding task, the tendency of users to type with excessive force and forcing users to maintain prolonged awkward and static postures are discussed in relation to CTD development. Suggestions for future research into this area and possible keyboard substitutes are also reviewed. Relevance to industry The increasing incidence of cumulative trauma disorders (CTDs) in the workplace has led to a search for possible contributing factors and ergonomic interventions. The computer keyboard input device has received much attention in the past and is believed by many to be a prime factor in the etiology of CTD occurrence. This paper reviews the scientific literature published thus far that explores the relationship between CTD development and keyboard use in the service industries.

Posture and Web Browsing: An Observational Study

This study was designed to identify the postures assumed by Web users and to compare these postures to those assumed during conventional text-entry tasks. Twenty-four participants were observed while performing various Web and typing tasks on a standard computer workstation. Across all postural measures, there were many instances where Web browsing postures differed in kind or frequency from typing postures. Further, there were some postural variances attributed to the different requirements of the three Web tasks (searching vs. learning vs. browsing). Overall, many postures were observed during the course of Web browsing that can be classified as detrimental towards the development of cumulative trauma disorders (CTD). Based on the results of this study, we provide guidelines for improving the posture of Web users.

An investigation of cumulative trauma disorders in the construction industry

Disorders associated with repeated trauma were the most common occupational illness in 1991, accounting for 61% of all occupational illnesses (Bureau of Labor Statistics). Research on cumulative trauma injuries in the construction industry is scarce. Therefore, the purpose of this research was to investigate factors associated with the development of cumulative trauma disorders (CTDs) in the construction industry. Additionally, this research evaluates the types of CTDs most prevalent in the construction industry. Results of this research show seven common CTDs prevalent in the construction industry: arpal Tunnel Syndrome, Tennis Elbow, Trigger Finger, Arthritis of the Thumb, Thumb/Wrist Tendinitis, Vibration Syndrome and Impingement. An index was developed to rank tasks based on possible development of CTDs by quantifying factors that contribute to the occurrence of these CTDs such as tool design, work task design, awkward posture, repetition, and application of force.

Occupational Therapists Whose Primary Area of Practice Is Hand Therapy

Hand therapists perform hand-intensive work and engage in tasks that require movements and postures cited in the literature to be risk factors for the development of cumulative trauma disorders. This study was conducted to determine the incidence, prevalence, and types of work-related cumulative trauma disorders of the hand, wrist, and elbow experienced by occupational therapists whose primary area of practice is hand therapy. A survey was sent to a national random sample of 289 occupational therapists, 227 of whom responded. A total of 328 upper-extremity injuries/syndromes were reported by 165 (79 %) of the respondents; 62 % of those injuries occurred as a result of cumulative work trauma. This study identified hand therapy as another occupation where cumulative trauma disorders are common. It is crucial that hand therapists become cognizant of their occupational risks and limitations so that such painful and disabling conditions can be prevented.

A system to predict internal factors related to the development of cumulative trauma disorders of the carpal tunnel and extrinsic flexor musculature

Non-physical balance training has demonstrated to be efficient to improve postural control in young people. However, little is known about the potential to increase corticospinal excitability by mental simulation in lower leg muscles. Mental simulation of isolated, voluntary contractions of limb muscles increase corticospinal excitability but more automated tasks like walking seem to have no or only minor effects on motor-evoked potentials (MEPs) evoked by transcranial magnetic stimulation (TMS). This may be related to the way of performing the mental simulation or the task itself. Therefore, the present study aimed to clarify how corticospinal excitability is modulated during AO + MI, MI and action observation (AO) of balance tasks. For this purpose, MEPs and H-reflexes were elicited during three different mental simulations (a) AO + MI, (b) MI and (c) passive AO. For each condition, two balance tasks were evaluated: (1) quiet upright stance (static) and (2) compensating a medio-lateral perturbation while standing on a free-swinging platform (dynamic).AO + MI resulted in the largest facilitation of MEPs followed by MI and passive AO. MEP facilitation was significantly larger in the dynamic perturbation than in the static standing task. Interestingly, passive observation resulted in hardly any facilitation independent of the task. H-reflex amplitudes were not modulated.The current results demonstrate that corticospinal excitability during mental simulation of balance tasks is influenced by both the type of mental simulation and the task difficulty. As H-reflexes and background EMG were not modulated, it may be argued that changes in excitability of the primary motor cortex were responsible for the MEP modulation. From a functional point of view, our findings suggest best training/rehabilitation effects when combining MI with AO during challenging postural tasks.

Work pace, stress, and cumulative trauma disorders

This paper discusses the potential roles of work pace and work pressure as risk factors in the development of cumulative trauma disorders. Specifically, electromyographic (EMG) data were collected from the forearm flexor muscles of workers performing a highly repetitive task. This task had previously been identified as one that involved a high incidence of cumulative trauma disorders. Workers were asked to increase and decrease their work pace for short periods of time. The EMG data indicated that faster work paces were accompanied by higher forces. However, it was also noted that unsuccessful attempts to speedup or slowdown produced similar increases and decreases in EMG activity, indicating that speed of movement was not the only factor contributing to the changes in muscular activity. The results are discussed in relation to the stress and tension associated with work pressure caused by machine pacing, production standards, and incentive systems.