Introduction: Complex regional pain syndrome (CRPS) is a form of neuropathic pain that sometimes develops after trauma or surgery. While diagnostic criteria have been debated, there is agreement participation in rehabilitation should be the primary management. However, there are gaps in the evidence guiding assessment and treatment choices for individuals with CRPS. The purpose of this thesis was to advance the rehabilitation of CRPS by 1) ongoing development and refinement of evaluations for the specific symptoms of CRPS, and 2) to investigate effectiveness of a new treatment (somatosensory rehabilitation) posited to address allodynia associated with CRPS. Methods: We conducted a series of 4 studies addressing various aspects of CRPS assessment and the somatosensory rehabilitation method: a) a cognitive debriefing study for content validation of the Patient-Reported Hamilton Inventory for CRPS; b) English translation and cultural validation of the Radboud Evaluation of Sensitivity; c) a retrospective cohort study of the effectiveness of somatosensory rehabilitation for allodynia in the upper limb; and d) a pilot study of the somatosensory rehabilitation method to consider the measurement properties of the embedded evaluation tools of allodynography and the rainbow pain scale, and to provide estimates for future controlled trials of effectiveness. Results: The cognitive debriefing study identified potentially problematic items, and constructs which needed enhancement in future versions of the PR-HICRPS assessment. The second paper reported the translation and cultural validation of the RES-E, finding support for test-retest reliability, internal consistency, and preliminary evidence for construct validity and reproducibility. The third paper presented preliminary evidence of a strong effect size for the SRM in an uncontrolled consecutive cohort. Finally, the fourth paper provides an interm analysis of the psychometric properties of allodynography and the rainbow pain scale, and estimates large sample sizes will be required for future trials. Discussion and Conclusion: None of the assessment tools described herein is ready for unrestricted use in clinical practice or research. Although the effect size estimates for somatosensory rehabilitation from the retrospective cohort are encouraging, the incomplete pilot data suggests large, multi-site trials and careful selection of the primary outcome measures will be required for future, rigorous trials of this method. / Dissertation / Doctor of Philosophy (PhD) / Complex regional pain syndrome (CRPS) is a painful collection of symptoms that can develop after trauma. Why it happens is not well understood, but most scientists and health care providers agree that rehabilitation should be the primary focus for managing the painful consequences of this condition. There is a need for simple and accurate ways to assess CRPS, as well as to treat it. Better assessment will support treatment that is more targeted to the symptoms of the individual. One of the very challenging symptoms experienced by persons with CRPS is painful sensitivity of the skin, also known as allodynia. This thesis describes the development and testing of several new patient-reported assessments for CRPS and allodynia, as well as two studies on a new method of treatment for allodynia.

This study sought to provide a description of the psychosocial profile of persons with complex regional pain syndrome (CRPS). CRPS is an excruciatingly painful and debilitating condition that is poorly understood by medical professionals. Its profound impact on an individual's quality of life prompts a closer examination of the psychosocial profile of individuals suffering from CRPS. The extant literature examining psychological variables associated with CRPS is inconclusive with regard to the role that these factors play in the course of the syndrome. It has been shown, however, that CRPS patients suffer tremendous physical discomfort and this is often reflected in increased emotional distress. The present study assesses level of pain, anxiety, depression, disability, intrusive thoughts, quality of life, and demographic variables utilizing a national sample obtained from an online survey distributed to members of an organization that provides resources to CRPS patients. Descriptive data are presented for all data gathered and specific correlates of quality of life were examined. Results of the study demonstrated that this sample endorsed high levels of anxiety and depression and reported low levels of both physical and mental quality of life. When compared to normative data, this sample endorsed more pain and anxiety than other pain populations and also endorsed lower mental and physical quality of life than other pain conditions. The psychosocial profile of individuals with CRPS type I did not vary significantly from individuals with type II. Intrusive thoughts were uniquely predictive of disability, physical quality of life, and mental quality of life after controlling for age, gender, and pain level. The role of intrusive thoughts in predicting disability and quality of life suggests a potential mechanism by which clinicians can target psychotherapeutic treatment. Understanding the psychosocial profile and psychological sequelae of this disorder will help both physicians and psychologists understand the impact of CRPS on patients and provide a pathway for improved comprehensive interdisciplinary treatments.

Introdução- Pacientes portadores de Síndrome Dolorosa Complexa Regional- I (SDCRI) lombar apresentam componente autonômico simpático associado à dor lombar facetaria, são submetidos de forma rotineira à sequência de 4 bloqueios autonômicos associado ao bloqueio do ramo mediano facetário, implicando em 4 procedimentos ambulatoriais por paciente, por semestre. Este estudo visou avaliar a eficácia da realização de ablação por radiofrequência após a realização do bloqueio teste. Métodos- Após aprovação do Comitê de Ética em Pesquisa e consentimento, 25 pacientes portadores de SDCR-I em membros inferiores e dor articular facetária lombar associada foram de forma prospectiva, submetidos a: 1) 4 sessões com intervalos semanais de bloqueio do ramo mediano facetário lombar de L2 a L5 bilateral, associado ao bloqueio do gânglio simpático autonômico L3. Quando a dor atingisse graduação VAS= 4 cm, foi considerado necessário repetição dos procedimentos realizados, e este tempo correspondeu ao tempo de analgesia, sendo calculado o custo anual e efeitos adversos por paciente. Os mesmos pacientes foram submetidos posteriormente a: 1) Bloqueios testes simpático e facetário, seguido de: 2) ablação por radiofrequência (RF) do ramo mediano facetário lombar de L2 a L5 bilateral, com 45 V, 80 segundos, 80 oC, + ablação por RF do gânglio simpático lombar de L3-L4 do lado acometido, 45V, 80 oC, 80 segundos em cada nível acometido, sob sedação consciente, com midazolam e alfentanil por via venosa. Cada paciente atuou como seu próprio controle. Resultados- 21 pacientes participaram da avaliação final. Cada paciente foi submetido a uma sequência semestral de bloqueios, sendo o tempo de analgesia após término do quarto procedimento 5±1 meses, e o custo anual de R$ 15.000,00. Quando os mesmos pacientes foram submetidos à RF, o tempo de analgesia foi em média 15±2 meses (p<0,001), havendo economia no primeiro ano de realização de RF de 23% no custo final e de 32% a 36% nos anos subsequentes, calculado por extrapolação. Durante o período de analgesia, a capacidade para realização de atividades rotineiras e a qualidade de sono melhoraram. Não foram observados efeitos adversos. Discussão- A realização de RF resultou menor número de internações anuais, menor custo anual e maior comodidade para o paciente, com mesma eficácia durante período de analgesia. / Introduction- Patients with Complex Regional Pain Syndrome type-I (CRPS-I) in lower members, often also present lumbar articular facetary pain, and are submitted as part of routine to a sequence of 4 weekly sympathetic blocks combined to facetary block, which sequence is usually repeated after six months for pain control. The study was designed to evaluate the efficacy of a test block followed by radiofrequency efficacy. Methods- After ethical approval and consent, 25 patients with CRPS-I in lower members were submitted to a 4-weekly sympathetic block at L3, combined to bilateral lumbar facetary block fromL2-L5. The sequence was repeated when pain VAS reached 4 cm, and this period was defined as time of analgesia. Thereafter, the same patients were submitted to a test block followed by radiofrequency (RF ablation of sympathetic ganglion L3 and L4 and bilateral ablation of facetary lumbar median branch from L2-L5), 45 V, 80 sec, 80 oC, under conscious sedation. Patients acted as their own control related to analgesia, routine activities, sleep and costs. Results: 21 patients completed the study. The analgesia time after the 4-block sequence was 5±1 months and the annual cost R$ 15.000,00 (USA$5000). The analgesia time after RF was 15±2 months (p<0.001) and the costs were reduced by 23% in the first year and 32%-36% in the following years extrapolation. Routine capacity and sleep at night were equally improved during analgesia for both treatments. There were no adverse effects. Discussion- Test block followed by RF resulted in 15 months of analgesia compared to 5 months for the routine technique of 4-blocks, in improved capacity and sleep comfort at night. Besides that, RF was costly effective, and reduced costs by 23% during the first year evaluation, followed by 32% to 36% cost reduction in following years, by extrapolation.

Complex regional pain syndrome (CRPS) is a chronic neuropathic pain disorder characterized by both central and peripheral symptoms that can be debilitating in children. CRPS treatment typically consists of intensive physical, occupational, and psychological therapy with evidence supporting the efficacy of this approach. Among these outcomes, some patients report significant improvements in pain while others report no change. Identifying baseline predictors of treatment resistance would refine our treatment approach and provide additional targets for intervention. The current study examined baseline brain structure via cortical thickness and gray matter volume (GMV) in 29 pediatric CRPS patients enrolled in an intensive pain rehabilitation program. All participants underwent MRI using a high-resolution T1-weighted sequence. Patients were categorized as pain treatment “responders” (n=19) or “non-responders” (n=10) based on change in reported pain levels from admission to follow up. Compared to treatment responders, non-responders demonstrated significantly less GMV in the bilateral nucleus accumbens p<0.05 and right: putamen p<0.01, pallidum p<0.05, and amygdala p<0.05. Furthermore, treatment non-responders exhibited significant cortical thickening in the left anterior insular cortex and medial frontal gyrus, and cortical thinning in the bilateral precentral gyrus and superior frontal gyrus; right: middle frontal gyrus, fusiform gyrus, inferior temporal gyrus, middle temporal gyrus, and anterior prefrontal cortex; and left: parahippocampal gyrus. Though we did see significant thinning of the primary motor cortex in treatment non-responders compared to responders, the majority of our findings were localized to regions associated with reward, motivation, learning, and emotion. We, therefore, postulate that treatment non-responders, when compared to responders, likely have an intrinsically reduced reward responsiveness, diminished motivation, and impaired learning, overall contributing to their negative treatment outcomes and chronification of pain. In conclusion, these baseline differences overall suggest these regional morphometric alterations may potentially serve as predictors of treatment response in pediatric CRPS. Furthermore, these areas may also indicate possible targets for future treatment.

Introdução- Pacientes portadores de Síndrome Dolorosa Complexa Regional- I (SDCRI) lombar apresentam componente autonômico simpático associado à dor lombar facetaria, são submetidos de forma rotineira à sequência de 4 bloqueios autonômicos associado ao bloqueio do ramo mediano facetário, implicando em 4 procedimentos ambulatoriais por paciente, por semestre. Este estudo visou avaliar a eficácia da realização de ablação por radiofrequência após a realização do bloqueio teste. Métodos- Após aprovação do Comitê de Ética em Pesquisa e consentimento, 25 pacientes portadores de SDCR-I em membros inferiores e dor articular facetária lombar associada foram de forma prospectiva, submetidos a: 1) 4 sessões com intervalos semanais de bloqueio do ramo mediano facetário lombar de L2 a L5 bilateral, associado ao bloqueio do gânglio simpático autonômico L3. Quando a dor atingisse graduação VAS= 4 cm, foi considerado necessário repetição dos procedimentos realizados, e este tempo correspondeu ao tempo de analgesia, sendo calculado o custo anual e efeitos adversos por paciente. Os mesmos pacientes foram submetidos posteriormente a: 1) Bloqueios testes simpático e facetário, seguido de: 2) ablação por radiofrequência (RF) do ramo mediano facetário lombar de L2 a L5 bilateral, com 45 V, 80 segundos, 80 oC, + ablação por RF do gânglio simpático lombar de L3-L4 do lado acometido, 45V, 80 oC, 80 segundos em cada nível acometido, sob sedação consciente, com midazolam e alfentanil por via venosa. Cada paciente atuou como seu próprio controle. Resultados- 21 pacientes participaram da avaliação final. Cada paciente foi submetido a uma sequência semestral de bloqueios, sendo o tempo de analgesia após término do quarto procedimento 5±1 meses, e o custo anual de R$ 15.000,00. Quando os mesmos pacientes foram submetidos à RF, o tempo de analgesia foi em média 15±2 meses (p<0,001), havendo economia no primeiro ano de realização de RF de 23% no custo final e de 32% a 36% nos anos subsequentes, calculado por extrapolação. Durante o período de analgesia, a capacidade para realização de atividades rotineiras e a qualidade de sono melhoraram. Não foram observados efeitos adversos. Discussão- A realização de RF resultou menor número de internações anuais, menor custo anual e maior comodidade para o paciente, com mesma eficácia durante período de analgesia. / Introduction- Patients with Complex Regional Pain Syndrome type-I (CRPS-I) in lower members, often also present lumbar articular facetary pain, and are submitted as part of routine to a sequence of 4 weekly sympathetic blocks combined to facetary block, which sequence is usually repeated after six months for pain control. The study was designed to evaluate the efficacy of a test block followed by radiofrequency efficacy. Methods- After ethical approval and consent, 25 patients with CRPS-I in lower members were submitted to a 4-weekly sympathetic block at L3, combined to bilateral lumbar facetary block fromL2-L5. The sequence was repeated when pain VAS reached 4 cm, and this period was defined as time of analgesia. Thereafter, the same patients were submitted to a test block followed by radiofrequency (RF ablation of sympathetic ganglion L3 and L4 and bilateral ablation of facetary lumbar median branch from L2-L5), 45 V, 80 sec, 80 oC, under conscious sedation. Patients acted as their own control related to analgesia, routine activities, sleep and costs. Results: 21 patients completed the study. The analgesia time after the 4-block sequence was 5±1 months and the annual cost R$ 15.000,00 (USA$5000). The analgesia time after RF was 15±2 months (p<0.001) and the costs were reduced by 23% in the first year and 32%-36% in the following years extrapolation. Routine capacity and sleep at night were equally improved during analgesia for both treatments. There were no adverse effects. Discussion- Test block followed by RF resulted in 15 months of analgesia compared to 5 months for the routine technique of 4-blocks, in improved capacity and sleep comfort at night. Besides that, RF was costly effective, and reduced costs by 23% during the first year evaluation, followed by 32% to 36% cost reduction in following years, by extrapolation.

Objectives: To determine the beliefs and describe the health care experiences of patients with complex regional pain syndrome. Methods: A survey tool for patients with complex regional pain syndrome was designed for this study. The survey tool collected self-reported measures associated with pain, disability, health care experiences, education, beliefs, and treatments. Results: Thirty-one patients attending physical therapy for complex regional pain syndrome (mean age 40.48; female n = 20) completed the survey. Patients with presented with high levels of pain and disability and reported various changes associated with altered neuroplasticity such as confused body part recognition, left/right discrimination, neglect, and spreading pain. The patients’ experiences with diagnostic testing and interventions are not in line with the current pain science research and/or evidence-based practice. Overall, patients are ill-informed, confused, and receive conflicting information. Discussion: The suffering associated with complex regional pain syndrome is real, as told by patients. This suffering coincides with a lack of consensus by health care providers and conflicting information on complex regional pain syndrome. Overall, patient experiences show health care providers are not up to date with the current best-evidence regarding complex regional pain syndrome.

<p>Appendices include current drafts of the Hamilton Inventory for Complex Regional Pain Syndrome and the associated user manual for the assessment tool.</p> / <p>Complex regional pain syndrome is a neurological condition characterized by a constellation of variable and seemingly disparate signs and symptoms for which there is presently no definitive diagnostic test. The opportunity exists for development of a condition-specific outcome measure for complex regional pain syndrome affecting any limb(s) that could be used by therapists, physicians and researchers to evaluate their patients, make treatment decisions, and monitor the changes in both impairments and quality of life experienced by those affected individuals. This thesis addresses outcome assessment in complex regional pain syndrome, incorporating 2 papers. The first is a systematic review of the current scope and psychometric rigor of outcome assessments available to health professionals to guide their management of this condition. The second paper describes the preliminary development steps of a new measurement tool for complex regional pain syndrome, with a focus on a cognitive debriefing study of current assessment practices and preferences of a cross-section of health professionals used to inform the definitions and user manual for a multi-disciplinary assessment. Finally, the thesis addresses areas for future refinement and testing of the proposed outcome measure.</p> / Master of Science (MSc)

Bakgrund: Komplext regionalt smärtsyndrom (CRPS) kännetecknas av en långvarig neuropatisk smärta i en kroppsdel där smärtan ej står i proportion till den utlösande händelsen. Syndromet kan inkludera sensibilitetsförändringar, ödem, hudfärgsförändringar samt rörlighets- och funktionsnedsättningar. Konsekvenserna kan bli stora i form av extrem smärta och försämrad livskvalitet. Syfte: Syftet med denna litteraturstudie var att hitta fysioterapeutiska behandlingsmetoder vid CRPS samt att undersöka deras effekter. Metod: Sökningar genomfördes i databaserna PubMed, Cinahl och Web of Science mellan januari och maj 2024. Sökningen resulterade i 88 artiklar varav 14 inkluderades. Resultat: 31 fysioterapeutiska behandlingsmetoder hittades. De vanligaste var Graded Motor Imagery (GMI), Mirror Therapy (MT), exponeringsbaserade interventioner och multimodala rehabiliteringsinsatser tillsammans med aerob träning. Exempel på andra metoder som användes var avslappningsmetoder, transkutan elektrisk nervstimulering (TENS), akupunktur, desensibilisering, tactile discrimination training och flertalet passiva behandlingsmetoder. Utfallsmåtten var olika mellan vuxna och yngre. Det som utvärderades var smärta, funktion, svullnad, livskvalitet, rädsla för smärta eller skada och smärtkatastrofiering. Konklusion: GMI kan förbättra smärta och funktion på medellång och lång sikt. MT kan förbättra smärta och funktion på kort och möjligen lång sikt. Graderad exponering eller exponering in vivo kan ge signifikanta förbättringar av funktion, smärta, katastroftankar kring smärta samt upplevd skadlighet av rörelser. Aerob träning kan minska smärta och/eller nedsatt funktion vid CRPS. Multimodala och tvärvetenskapliga insatser är viktiga för att uppnå ett bra resultat. Fler randomiserade kontrollerade studier behövs för att kunna avgöra långtidseffekterna av interventionerna. / Background: Complex regional pain syndrome (CRPS) is characterized by a long-term neuropathic pain in a body part where the pain is disproportionate to the triggering event. The syndrome may include changes in sensitivity, changes of skin color, oedema, reduced mobility and disability. The consequences can become severe such as extreme pain and reduced quality of life. Purpose: To find physiotherapeutic treatment methods for CRPS and to investigate their effects. Method: Searches were conducted in the databases PubMed, Cinahl and Web of Science between January-May 2024. The search resulted in 88 articles of which 14 were included. Results: 31 physiotherapeutic treatment methods were found. The most common ones were Graded Motor Imagery (GMI), Mirror Therapy (MT), exposure-based interventions and multimodal rehabilitation interventions along with aerobic exercise. Examples of other methods used were relaxation methods, transcutaneous electrical nerve stimulation (TENS), acupuncture, desensitization, tactile discrimination training and several passive methods of treatment. The outcome measures varied between adults and younger people. Pain, function, swelling, quality of life, fear of pain or injury and pain catastrophizing were evaluated. Conclusion: GMI may provide clinically meaningful medium- and long-term improvements in both pain and function. MT can improve pain and function in short and possibly long term. Graded exposure or exposure in vivo can significantly improve motor function, pain, pain-catastrophizing as well as perceived harmfulness of activities. Aerobic exercise may reduce pain and/or impaired motor function related to CRPS. Multimodal and interdisciplinary efforts are important to achieve good results. More randomized controlled trials are needed to determine the long-term effects of the interventions.

Bibliographic identification CHASÁKOVÁ, Ludmila. Utility of the "mirror therapy" in the treatment complex regional pain syndrome (type I). Prague: Charles University, 2nd Faculty of Medicine, Department of Rehabilitation and Sports Medicine, 2014. 105 s. Supervisor Mgr. Stanislav Machač. Annotation Objectives: Introduction of "mirror therapy" (MT) principles in patients with Type 1 complex regional pain syndrome (CRPS). Verification of the effectiveness of the MT in terms of sensory, functional and morphological changes. Participants: Sixteen patients (14 women and 2 men, age 55.3±10.5 years) and 10 controls (7 women and 3 men, age 54.9±7.6 years) were included in this study. All of them were diagnosed as patients with Type I CRPS. Methods and measure: The intervention group underwent 6 weeks of MT. Both groups recorded numerical scale pain for 6 weeks. At the beginning and end of the period, all probands underwent examination including: range of motion of wrist flexion and extension, thenar temperature side-to-side difference, volume of the hand and forearm, dynamometry, PegBoard, ability to close the fist, Wind-Up, referred sensations and EQ-5D-3L questionnaire. Results: A statistically significant reduction in pain at rest and during movement was found in the intervention group, not in the control group....

Le Syndrome de la Douleur Régionale Complexe (SDRC) est une maladie se manifestant par des troubles moteurs et atteint généralement les membres supérieurs. Bien que l'effet positif de la thérapie de miroir sur SDRC ait été prouvé, la tête du patient fixée et orientée en direction du miroir et l'exigence d'ignorer le membre intact limite encore cette thérapie. Dans ce contexte, premièrement la pseudo-haptique est appliquée dans le cas de la thérapie physique pour la main des patients affectés par le SDRC. Ainsi, le premier travail que nous avons effectué était de comprendre comment l'effet pseudo-haptique influence le comportement moteur de la main de l'utilisateur. A cet effet, des tâches de discrimination de rigidité ont été conduites consistant à discriminer la raideur d'un ressort virtuel avec celle de trois ressorts réels de raideurs différentes. Il existe deux types de thérapie pour la réhabilitation des patients atteints de SDRC : kinésiologique et occupationnelle, qui visent à récupérer respectivement les fonctions motrices de base et de travail du membre affecté. Concernant la thérapie kinésiologique, une application fondée sur la technologie Leap Motion et Unity3D a été développée permettant de manipuler la relation entre le mouvement de la main physique de l'utilisateur et le mouvement rendu/virtuel de l’avatar. L’application a été validée par une étude pilote réalisée au CHU de Grenoble avec des patients, des sujets sains et une équipe médicale (docteurs et kinésithérapeutes. Durant les tests, le mouvement rendu de la main est présenté sur l’écran de l’ordinateur: identique, amplifié ou réduit. Le retour des sujets a montré qu’ils n’avaient pas des sensations d’inconfort en utilisant l’application développée. L’équipe médicale, quant à elle, a manifesté un vif intérêt concernant l’utilisation de l’application en thérapie kinésithérapique. A cause de la fonction motrice anormale et de la douleur chronique nous avons tenu compte de l'endurance à la fatigue des patients atteints de SDRC A cet effet, une nouvelle méthode pour l'évaluation de la fatigue de la tâche en démontage fondée sur la dépense d'énergie métabolique et l’estimation de la fatigue musculaire a été proposée. Elle permet d’estimer les niveaux de fatigue associés à des tâches de démontage différentes. La méthode proposée est validée par une série de tests expérimentaux de chargement effectués dans un environnement de RV. D’autre part, les niveaux de fatigue sont évalués en analysant des signaux EMG des muscles impliqués du bras de l’opérateur. Enfin, les résultats analytiques issus du modèle proposé et les résultats expérimentaux obtenus à partir de l'analyse des signaux EMG ont été comparés et montré une très bonne corrélation entre eux. / Complex Regional Pain Syndrome (CRPS) is a disease which companies with motor disorder and is generally affecting the upper limbs. Although the positive effect of mirror therapy on CRPS has been proved, the patient’s fixed head oriented towards the mirror and the requirement of ignoring the intact limb still limits this therapy. In this context, firstly the pseudo-haptics is applied in the case of physical therapy for hand affected CRPS patients. Thus, our first work was to understand how the pseudo-haptic feedback affects the user’s motor behavior of hand. For this purpose, stiffness discrimination tasks were performed consisting in discriminating the stiffness of one virtual spring with three different compared real springs. For rehabilitation of CRPS patients, there are two types of therapy: a kinesiological and an occupational one, respectively aiming at recovering the basic and working motor functions of patient‘s affected limb. For the kinesiological therapy we developed a VR application, based on Leap Motion technology and Unity3D software, allowing to manipulate the relationship between the user’s physical hand motion and the rendered avatar virtual motion. The application was validated by a pilot study performed at University Hospital Center in Grenoble with patients, healthy subjects and medical staff (doctors and kinesitherapists). During the experiments the rendered hand motion on the computer screen, is shown identical, amplified or reduced compared to the users’ real hand motion. Users’ feedback shown that they had no uncomfortable feeling with using the developed application. Medical staff expressed a strongly interest in using the application in the kinesiological therapy. Due to the motor abnormal function and chronic pain, we also considered the fatigue in the muscles during rehabilitation. For this purpose, a new method for disassembly task fatigue evaluation based on metabolic energy expenditure and muscle fatigue estimation is proposed. It is validated by a set of experimental loading tests performed in a specially realized test bench and integrated in a VR environment. The analytical model for mechanical energy expenditure is also proposed allowing to evaluate different fatigue levels. On the other hand, the fatigue levels are evaluated by analyzing the recorded EMG signals on the involved muscles in operator’ arm. The analytical results, calculated based on the proposed model and the experimental results, obtained from the EMG signals analysis, were compared and showed a (very) good correlation between them.