Surgeons' posture and muscle strain during laparoscopic and robotic surgery.

BACKGROUND: It is assumed that conventional laparoscopy (LAP) and robotic-assisted laparoscopic surgery (RALS) differ in terms of the surgeon's comfort. This study compared muscle workload, work posture and perceived physical exertion of surgeons performing LAP or RALS. METHODS: Colorectal surgeons with experience in advanced LAP and RALS performed one of each operation. Bipolar surface electromyography (EMG) recordings were made from forearm, shoulder and neck muscles, and expressed relative to EMG maximum (%EMGmax ). The static, median and peak levels of muscle activity were calculated, and an exposure variation analysis undertaken. Postural observations were carried out every 10 min, and ratings of perceived physical exertion before and after surgery were recorded. RESULTS: The study included 13 surgeons. Surgeons performing LAP showed higher static, median, and peak forearm muscle activity than those undertaking RALS. Muscle activity at peak level was higher during RALS than LAP. Exposure variation analysis demonstrated long-lasting periods of low-level intensity muscle activity in the shoulders for LAP, in the forearms for RALS, and in the neck for both procedures. Postural observations revealed a greater need for a change in work posture when performing LAP compared with RALS. Perceived physical exertion was no different between the surgical modalities. CONCLUSION: Minimally invasive surgery requires long-term static muscle activity with a high physical workload for surgeons. RALS is less demanding on posture.

ANTECEDENTES: Se asume que la cirugía laparoscópica (laparoscopic, LAP) y la cirugía laparoscópica asistida por robot (robotic-assisted laparoscopic surgery, RALS) difieren en cuanto a la comodidad del cirujano. En este estudio se comparó la carga de trabajo muscular, la postura de trabajo y el esfuerzo físico percibido por los cirujanos al realizar LAP o RALS. MÉTODOS: Trece cirujanos colorrectales con experiencia en LAP avanzada y RALS realizaron una operación con cada uno de los abordajes. Se registró la electromiografía de superficie bipolar en los músculos del antebrazo, del hombro y del cuello, y se expresó en relación con el EMG máximo (% EMGmax). Se calculó el nivel de actividad muscular estático, mediano y pico, y se realizó un análisis de variación de la exposición. Las observaciones posturales se llevaron a cabo cada diez minutos y se registraron las valoraciones del esfuerzo físico percibido antes y después de la cirugía. RESULTADOS: La práctica de LAP mostró una mayor actividad muscular estática, mediana y pico del antebrazo en comparación con la práctica de RALS. El hombro izquierdo mostró la mayor actividad muscular en RALS a nivel máximo. El análisis de variación de exposición demostró periodos prolongados de actividad muscular de baja intensidad para LAP en los hombros, para RALS en los antebrazos y para ambos en el cuello. Las observaciones posturales mostraron una mayor necesidad de un cambio en la postura de trabajo al realizar LAP en comparación con RALS. El esfuerzo físico percibido no fue diferente entre ambas modalidades quirúrgicas. CONCLUSIÓN: La cirugía mínimamente invasiva requiere una actividad muscular estática prolongada con una alta carga de trabajo físico para los cirujanos. RALS es menos exigente en el aspecto postural.

Surgeons' muscle load during robotic-assisted laparoscopy performed with a regular office chair and the preferred of two ergonomic chairs: A pilot study.

Surgeons work in awkward work postures and have high precision demands - well-known risk factors for musculoskeletal pain. Robotic-assisted laparoscopy is expected to be less demanding compared to conventional laparoscopy; however, studies indicate that robotic-assisted laparoscopy is also associated with poor ergonomics and musculoskeletal pain. The ergonomic condition in the robotic console is partially dependent upon the chair provided, which often is a regular office chair. Our study quantified and compared the muscular load during robotic-assisted laparoscopy using one of two custom built ergonomic chairs and a regular office chair. The results demonstrated no differences that could be considered clinically relevant. Overall, the study showed high levels of static and mean muscular activity, increased perceived physical exertion from pre-to-post surgery, and moderate to high risk for musculoskeletal injuries measured by the Rapid Upper Limb Assessment worksheet. Authors advocate for further investigation in surgeons' ergonomics and physical work demands in robotic surgery.

Effect of resistance training on headache symptoms in adults: Secondary analysis of a RCT.

BACKGROUND: While strength training for the neck and shoulder muscles may be effective in reducing headache, the optimal combination of exercise frequency and duration is unknown. This study investigates the effect of different time-wise combinations of one weekly hour of strength training for the neck and shoulder muscles on headache frequency, intensity, and use of analgesics. METHODS: A total of 573 office workers were randomly allocated at the cluster-level to five groups; 3 × 20 min a week of minimally supervised (3MS), 1 × 60 (1WS), 3 × 20 (3WS) or 9 × 7 (9WS) min a week of supervised high-intensity strength training for 20 weeks, or to a reference group without training (REF). Headache frequency, intensity, and use of analgesics in relation to headache were determined by questionnaire at baseline and follow-up. RESULTS: The intention-to-treat analysis showed reduced headache frequency and intensity of approximately 50% in all training groups compared with REF at 20-week follow-up (P < 0.001). Use of analgesics was lower in the supervised training groups (1WS, 3WS and 9WS), but not in the group with minimal training supervision (3MS), compared with REF at follow-up. CONCLUSION: One hour of specific strength training - regardless of the distribution during the week - effectively reduced both headache frequency and intensity in office workers. Thus, a large time-wise flexibility exists when implementing specific strength training at the workplace. However, only supervised training led to a reduction in use of analgesics for headache.

The utility of EMG interference pattern analysis in botulinum toxin treatment of torticollis: a randomised, controlled and blinded study.

OBJECTIVE: The significance of electromyography (EMG) guidance in botulinum toxin (BT) treatment has been much debated. The aim of this study was to evaluate if EMG guidance in the treatment of torticollis in BT-naive patients had a better outcome than treatment after clinical evaluation alone. METHODS: Twenty-six patients with torticollis were included and treated for 1 year in this prospective, blinded study. Quantitative EMG was performed simultaneously in the four most frequently affected muscles: the sternocleidomastoid muscles and the posterior neck muscles on both sides. EMGs were analysed for turns per second. Clinical ratings were performed by an experienced neurologist (A). Injections were given by another neurologist (B), who was blinded to the ratings. In group 1, the results of the EMG were available to the treating neurologist B, whereas in group 2, neurologist B was blinded. In group 1, treatment with BT was given when turns per second were higher than 100. RESULTS: In patients treated guided by EMG, clinical outcome, evaluated by objective ratings, was better than in patients treated based on clinical judgement alone (p = 0.05). In group 2, 105 muscles were treated with BT. Of these, 37 did not show dystonic EMG activity. CONCLUSIONS: Treatment with BT guided by EMG results in better clinical outcome than treatment without EMG and reduces the amount of BT used. SIGNIFICANCE: EMG guidance by interference pattern analysis may optimise BT treatment in torticollis by a more precise injection and may reduce side effects and the risk of development of antibodies to BT.

Reduced jaw opening from paradoxical activity of mandibular elevator muscles treated with botulinum toxin.

The aim of the study was the effect of injections with botulinum toxin A (BTX-A) on reduced jaw opening, caused by paradoxical, antagonistic activity of jaw elevator muscles after brain stem lesions. The study included a male (51 years) and a female (69 years) patient. Subjective assessment, clinical recordings, muscle blocks and electromyography (EMG) were used to diagnose paradoxical activity, and to plan, guide and evaluate the treatment. The paradoxical innervation pattern was unilateral in the male and bilateral in the female. The paradoxical activity during jaw opening amounted to 24-109% of the level during maximum biting, and bursts of paradoxical activity were also present during chewing. EMG-guided blocks and later BTX-A injections of the affected muscles increased the opening by 9-23 mm from pre-treatment values of 15-18 mm, and normalized chewing. The study proved BTX-A to be an effective treatment for reduced jaw opening caused by paradoxical activity. Treatment was optimized by EMG evaluation of the current activity of the jaw elevator muscles, permitting individual treatment plans with longer intervals between BTX-A injections and lower doses than with conventional treatment for oromandibular dystonia. Thus the treatment only had to be repeated one to two times per year to maintain acceptable jaw mobility.

Long-term botulinum toxin treatment of cervical dystonia--EMG changes in injected and noninjected muscles.

OBJECTIVE: To evaluate changes in quantitative EMG of injected and noninjected sternocleidomastoid muscles following long-term unilateral botulinum toxin treatment of cervical dystonia. METHODS: We investigated 27 patients with cervical dystonia, who received repeated unilateral botulinum toxin injections of the sternocleidomastoid muscle, with quantitative EMG at rest and at maximal voluntary contraction. The patients had on the average 7.1 botulinum toxin treatments and the follow-up period was on the average 31 months (SD 16). RESULTS: After the first treatment, the injected sternocleidomastoid muscles showed a significant decrease in turns/s (mean 45%) and amplitude (mean 52%) at rest, and in amplitude at maximal flexion (mean 24%) and rotation (mean 39%). Except for a reduction in turns/s at rotation (mean 19%) no further reductions in EMG parameters were seen after long-term treatment. The contralateral noninjected sternocleidomastoid muscles showed no significant change in EMG activity after the first BT treatment, but after long-term treatment a significant reduction in turns/s and amplitude at both maximal flexion (turns: mean 28%; amplitude: mean 25%) and rotation (turns/s: mean 32%; amplitude: mean 25%) were seen as compared to pretreatment values. CONCLUSION: The results indicate that there seems to be no cumulative chemodenervation by repeated botulinum toxin injections of sternocleidomastoid muscles measured by quantitative EMG. Contralateral noninjected sternocleidomastoid muscles however, seem to be affected following long-term treatment. The mechanism behind this finding is unknown.

[Myotonic dystrophy]. / Dystrophia myotonica.

Myotonic dystrophy (MD) is illustrated by a characteristic case report. MD is a dominantly inherited multi-organic disease with complete penetrance, but with highly variable expression illustrated by the near relatives of this patient. The disease usually follows a slow, progressive course. The cardinal symptoms are myotonia, muscle atrophia, cataract and a characteristic facial appearance. Cardial arrhythmias, endocrine and mental changes also occur. The liability to arrhythmias and the weakened respiratory muscles of the patients which lead to ventilatory insufficiency makes anesthesia and surgical operation risky. The diagnosis, which is made by electromyography, is easy in typical cases, but suspicion that the disease is present is seldom raised in very mild cases if there is no recognition of familial cases. Meticulous examination of near relatives of severe cases is therefore essential to take advantage of the possibilities of prenatal diagnosis recently made possible through developments in DNA technology.

Spasm index in subarachnoid haemorrhage: consequences of vasospasm upon cerebral blood flow and oxygen extraction.

A spasm index, defined as transcranial Doppler detected flow velocity in the middle cerebral artery divided by regional cortical cerebral blood flow (CBF), was used on 24 patients with subarachnoid haemorrhage (SAH). The aim was to estimate degree and time course of vasospasm, even in cases with great day-to-day variation in CBF, and correlate to CBF and oxygen extraction. All patients showed increase in spasm indices with peak index in the second or third week. The index seemed stable in spite of day-to-day fluctuations in CBF. Severe vasospasm were associated with poor clinical condition, reduced CBF (less than 30) and high AVDO2. The same picture could be seen with minor degree of vasospasm, probably, in some cases, due to high intracranial pressure. The results suggest that the spasm index is useful in monitoring patients with subarachnoid haemorrhage, and that severe vasospasm has a negative influence on clinical condition, CBF and oxygen extraction.