Gunnevi Sundelin

Perceived pain before and after three exercise programs--a controlled clinical trial of women with work-related trapezius myalgia.

Abstract The effect of exercise on neck–shoulder pain was studied in 103 women with work‐related trapezius myalgia randomized into three exercise groups and a control group. One group trained strength, the second muscular endurance and the third co‐ordination. The exercise groups met three times weekly for 10 weeks. Pain assessment was made on three visual analogue scales, indicating pain at present, pain in general and pain at worst. Pain thresholds were measured in the trapezius muscle with a pressure algometer. A pain drawing was completed. The rated pain decreased significantly (P<0.05) on the VAS describing pain at worst in the strength and endurance groups. Pressure sensitivity decreased significantly (P<0.05) in four triggerpoints in the exercise groups. No changes were seen in the extent of painful body area in any group. Comparison of exercisers (n=82) and controls (n=21) showed significantly larger pain reductions on VAS pain at present and VAS pain at worst among exercisers. All three exercise programs showed similar decreases of pain which indicates that the type of exercise is of less importance to achieve pain reduction.

Discomfort and load on the upper trapezius muscle when operating a wordprocessor.

Abstract Surface electromyogram recordings from the descending part of the trapezius muscle and discomfort ratings were assessed for six female VDT wordprocessor operators during their work. Each operator was studied during three work periods of 3 to 5 hours on different days. During one of the work periods, short pauses (15 s) were introduced every sixth minute. A static local muscular load of 32 and 30% of the maximal voluntary contraction was found on the right and the left side, respectively. The median and peak muscular loads during work were low. There was a significant negative correlation between pauses and static load on the right upper trapezius muscle. The rating of perceived discomfort was less after the work periods with short pauses than after the work periods without.

Quadriceps Activation in Closed and in Open Kinetic Chain Exercise

PURPOSE For treatment of various knee disorders, muscles are trained in open or closed kinetic chain tasks. Coordination between the heads of the quadriceps muscle is important for stability and optimal joint loading for both the tibiofemoral and the patellofemoral joint. The aim of this study was to examine whether the quadriceps femoris muscles are activated differently in open versus closed kinetic chain tasks. METHODS Ten healthy men and women (mean age 28.5 +/- 0.7) extended the knees isometrically in open and closed kinetic chain tasks in a reaction time paradigm using moderate force. Surface electromyography (EMG) recordings were made from four different parts of the quadriceps muscle. The onset and amplitude of EMG and force data were measured. RESULTS In closed chain knee extension, the onset of EMG activity of the four different muscle portions of the quadriceps was more simultaneous than in the open chain. In open chain, rectus femoris (RF) had the earliest EMG onset while vastus medialis obliquus was activated last (7 +/- 13 ms after RF EMG onset) and with smaller amplitude (40 +/- 30% of maximal voluntary contraction (MVC)) than in closed chain (46 +/- 43% MVC). CONCLUSIONS Exercise in closed kinetic chain promotes more balanced initial quadriceps activation than does exercise in open kinetic chain. This may be of importance in designing training programs aimed toward control of the patellofemoral joint.

Pathological mechanisms implicated in localized female trapezius myalgia

Abstract Myalgia localized to the neck and shoulder in women is a growing problem both in the general population and in the industrial world. The aim of this study was to investigate the mechanisms involved in work‐related myalgia. In 21 women (age, 38.7±5.5 years), muscle biopsies were obtained from the upper part of the trapezius and the morphologic and metabolic characteristics of muscle fibres were analyzed. The patients indicated the number of painful areas on a pain drawing and the intensity of pain was assessed using a visual analogue scale (VAS). Two groups were formed on the basis of the median values: lower pain level and higher pain level. Trapezius muscles were characterized by the large size of type I fibres and the low capillary to fibre area ratio for both type I and type IIA fibres. Patients with the highest pain scores had the lowest capillary to fibre area ratio for type I fibres (coefficient correlation r=−0.45 and P<0.05). Moreover, the proportion of cytochrome c oxidase (COX)‐negative fibres seen in the cross‐sections was significantly higher in the group of patients which had the higher pain and more painful areas than in the group of patients with lower pain level and painful areas (P<0.05). The significant increase (P<0.05) of the size of the type I fibres in trapezius myalgia point to the special strain imposed upon type I muscle fibres during work tasks. Cytochrome oxidase c deficiency which is indicative of an energy crisis within muscle cells and the low capillary to fibre area ratio which might impair oxygen delivery and removal of metabolites in the working muscles are both associated with pain in the trapezius muscle.

Effects on physical performance and pain from three dynamic training programs for women with work-related trapezius myalgia

To compare training programs for women with trapezius myalgia regarding physical performance and pain, 102 women were randomized to strength, endurance, co-ordination and non-training groups. Before and after the intervention, static strength and dynamic muscular endurance in shoulder muscles were measured on a Cybex II dynamometer. Muscle activity in shoulder muscles was monitored via surface EMG. The signal amplitude ratio between the active and passive phase of repeated contractions indicated the ability to relax. Pain at present, pain in general and pain at worst were measured on visual analogue scales. After training, within group comparisons showed that the training groups rated less pain, and in the strength training group ratings of pain at worst differed from the non-training group. Using the non-training group as a reference, static strength increased in the strength and endurance training groups and muscular endurance in all training groups. The study indicates that regular exercises with strength, endurance or co-ordination training of neck/shoulder muscles might alleviate pain for women with work-related trapezius myalgia.

Effects of training on female trapezius Myalgia: An intervention study with a 3-year follow-up period.

Study Design. A prospective randomized clinical trial was conducted. Objective. To evaluate the long-term effects of three training interventions on women with work-related trapezius myalgia. Summary of Background Data. Studies with long-term follow-up evaluation of interventions for neck pain are scarce and usually cover fewer than 12 months. Methods. For this study, 126 women with work-related trapezius myalgia were randomized into strength, muscular endurance, or coordination training or into a nontraining reference group. Intervention training occurred three times a week for 10 weeks. Assessment of pain intensity, pressure pain thresholds, symptom frequency, perceived health, and work and exercise habits was performed before and immediately after interventions, then at clinical examinations 8 months and 17 months after the interventions. Participation rates at these follow-up assessments were 84% and 81%. At 3 years after the interventions, a questionnaire was answered by 94% of the participants, 17 of whom were dropouts that never participated in any of the four intervention groups. Results. All the training programs showed similar pain reducing effects immediately after the interventions. Pain reductions were maintained at follow-up evaluations, but at the 8-month follow-up assessment, there were no differences between the training groups and the reference group on any variable. At 3 years after the interventions, the intervention groups did not differ from the dropout group. Almost half (49%) of the women had persistent symptoms at the 3-year follow-up assessment. Conclusions. The long-term effect of all the training programs was low. Pain in neck and shoulder muscles was persistent in a large proportion of the women over the 3 years.

Positive attitudes and preserved high level of motor performance are important factors for return to work in younger persons after stroke : a national survey

OBJECTIVE Significant numbers of younger persons with stroke should be given the opportunity to return to work. The aim of this study was to investigate factors of importance for return to work among persons after first ever stroke, in the age range 18-55 years. METHODS A questionnaire was sent to all persons who had experienced a first ever stroke, 18-55 years of age, registered in the Swedish national quality register for stroke care, Riks-Stroke. Of the 1068 who answered the questionnaire, 855 (539 men and 316 women) were in paid employment before their stroke, and were included in this study. RESULTS Sixty-five percent returned to work and, of these, an equal proportion were men and women. Significant factors associated with return to work were the perceived importance of work (odds ratio (OR) 5.10), not perceiving themselves as a burden on others (OR 3.33), support from others for return to work (OR 3.66), retaining the ability to run a short distance (OR 2.77), and higher socioeconomic codes (OR 2.12). A negative association was found between those rehabilitated in wards intended for younger persons and return to work (OR 0.37). CONCLUSION External support from others, and positive attitudes towards return to work, were factors associated with successful return to work after stroke. Contrary to what was expected, independence in personal activities of daily living and cognitive factors were not associated with return to work to the same extent as persistent higher level of physical functions, such as ability to run a short distance.

Cervical helical axis characteristics and its center of rotation during active head and upper arm movements—comparisons of whiplash-associated disorders, non-specific neck pain and asymptomatic individuals

The helical axis model can be used to describe translation and rotation of spine segments. The aim of this study was to investigate the cervical helical axis and its center of rotation during fast head movements (side rotation and flexion/extension) and ball catching in patients with non-specific neck pain or pain due to whiplash injury as compared with matched controls. The aim was also to investigate correlations with neck pain intensity. A finite helical axis model with a time-varying window was used. The intersection point of the axis during different movement conditions was calculated. A repeated-measures ANOVA model was used to investigate the cervical helical axis and its rotation center for consecutive levels of 15 degrees during head movement. Irregularities in axis movement were derived using a zero-crossing approach. In addition, head, arm and upper body range of motion and velocity were observed. A general increase of axis irregularity that correlated to pain intensity was observed in the whiplash group. The rotation center was superiorly displaced in the non-specific neck pain group during side rotation, with the same tendency for the whiplash group. During ball catching, an anterior displacement (and a tendency to an inferior displacement) of the center of rotation and slower and more restricted upper body movements implied a changed movement strategy in neck pain patients, possibly as an attempt to stabilize the cervical spine during head movement.

The effects of different training programs on the trapezius muscle of women with work-related neck and shoulder myalgia

Abstract The aim of this study was to examine the effects of training on the structural characteristics of the trapezius muscle in women with work-related trapezius myalgia. Muscle biopsies were taken before and after 10 weeks of three different training programs (strength, endurance and coordination). Enzyme-immunohistochemical analysis was performed to assess muscle fibre types, fibre area, capillary supply and cytochrome c oxidase (COX) activity. There was an increase in the proportion of type IIA fibres in strength trained group (P < 0.05). Strength training elicited a preferential increase in the area of type II fibres (P < 0.05); both strength and endurance programs induced an increase in the number of capillaries around type I and IIA muscle fibres. Finally, all training programs induced a decrease in the proportion of COX-negative fibres. In conclusion, the trapezius muscle of women with neck and shoulder myalgia is characterised by a great potential of adaptation to physical exercise over a period of 10 weeks. The significant changes in the number of capillaries and the specific changes induced by training at the level of muscle fibres might well explain the improvement of muscle function.

Reach performance and postural adjustments during standing in children with severe spastic diplegia using dynamic ankle-foot orthoses.

OBJECTIVE To investigate the co-ordination between reaching, ground reaction forces and muscle activity in standing children with severe spastic diplegia wearing dynamic ankle-foot orthoses compared with typically developing children. DESIGN Clinical experimental study. SUBJECTS Six children with spastic diplegia (Gross Motor Function Classification System level III-IV) and 6 controls. METHODS Ground reaction forces (AMTI force plates), ankle muscle activity (electromyography and displacement of the hand (ELITE systems) were investigated while reaching for an object. RESULTS For the children with severe spastic diplegia who were wearing dynamic ankle-foot orthoses, co-ordination between upward and forward reach velocity differed regarding the temporal sequencing and amplitude of velocity peaks. During reaching, these children lacked interplay of pushing force beneath the reach leg and braking force beneath the non-reach leg and co-ordinated ankle muscle activity, compared with controls. CONCLUSION The results suggest differences in reach performance and postural adjustments for balance control during a reaching movement in standing between children with spastic diplegia Gross Motor Function Classification System level III-IV, wearing dynamic ankle-foot orthoses compared with typically developing children.