Rehabilitation of neck-shoulder pain in women industrial workers: a randomized trial comparing isometric shoulder endurance training with isometric shoulder strength training.

OBJECTIVES: To study whether isometric shoulder endurance was more advantageous than isometric shoulder strength training in reducing pain and perceived exertion and to increase shoulder function through improved muscle endurance and strength. DESIGN: Randomized trial. SETTING: Three occupational health care centers. PARTICIPANTS: Women industrial workers with nonspecific neck-shoulder pain. The International Classification of Diseases, 10th Revision (ICD-10) diagnosis was "cervicobrachial syndrome" (M53.1). Thirty-eight patients completed the isometric shoulder endurance training and 31 patients completed the isometric shoulder strength training. INTERVENTION: Twelve weeks of training. MAIN OUTCOME MEASURES: Self-reported pain and rating of perceived exertion (RPE), arm motion performance test, shoulder muscle strength, shoulder muscle endurance, and shoulder functional tests, as well as follow-up after supervised training had ended. RESULTS: The isometric shoulder strength training resulted in an almost one-scale step decrease in RPE at work and a 5% to 15% improvement of arm motion performance compared with the endurance training. The isometric shoulder strength training more effectively improved left side shoulder abduction strength (p < .026), but no major differences were found for the other strength measurements. The isometric shoulder endurance training was not more successful than the strength training in the endurance test (p .51 to .81). CONCLUSIONS: Physical training programs for neck-shoulder pain may include isometric shoulder muscular strength exercise in addition to isometric shoulder endurance training, rather than endurance training only.

Exercise and variations in neuropeptide concentrations in rheumatoid arthritis.

The aim of the present study was to investigate the influence of an exercise program on neuropeptide concentrations, disease activity, impairments and disabilities in rheumatoid arthritis (RA). Eleven females (median age 60 years, median disease duration 6.5 years, ARA functional classes I or II) exercised 30 min daily for 4 weeks. The urine concentrations of calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) and neuropeptide Y-like immunoreactivity (NPY-LI) were analyzed 1 week prior to exercise start, at exercise start, after 2 and 4 weeks of exercise, and after a 4-week follow-up period. Measurements of disease activity, aerobic capacity, grip force, limb muscle function, and activities of daily living (ADL) were also undertaken. The results indicate a decrease (md 5.64 pM to md 3.48 pM, P

[Pain analysis is vital in rheumatic diseases. Pain often causes much worry to patients]. / Smärtanalys vital vid reumatiska sjukdomar. Smärtan oftast patientens största bekymmer.

The article consists of a synthesis of a rheumatic pain symposium held at the annual meeting of the Swedish Medical Association in 1996. Various aspects of pain in rheumatic diseases were discussed, such as physiological, neurohumoral and neurogenic mechanisms, sensory stimulation treatment, differentiation of mechanical and inflammatory pain, quality enhancement by improved co-operation between primary and tertiary care facilities, pharmacological treatment with (centrally and peripherally acting) opioids, selective cyclo-oxygenase inhibitors, and NMDA (N-methyl-D-aspartate) receptor antagonists. For patients with rheumatic disorders exacerbated by pain problems, as for other patients, a pain diagnosis is of fundamental importance. This can be achieved by analysis of the social, psychological, physiological and medical factors contributing to the cause and degree of pain and to pain behaviour, and of the extent to which the pain may be nociceptive (i.e., inflammatory, mechanical, or ischaemic in origin), neurogenic or idiopathic. Pain analysis should be followed by individualised treatment focused on the patient's most crucial problems, thus enhancing the prospect of optimal treatment outcome.

[Pain analysis is vital in rheumatic diseases. The pain is often the patient's worst problem]. / Smärtanalys vital vid reumatiska sjukdomar. Smärtan oftast patientens största bekymmer.

The article consists of a synthesis of a rheumatic pain symposium held at the annual meeting of the Swedish Medical Association in 1996. Various aspects of pain in rheumatic diseases were discussed, such as physiological, neurohumoral and neurogenic mechanisms, sensory stimulation treatment, differentiation of mechanical and inflammatory pain, quality enhancement by improved cooperation between primary and tertiary care facilities, pharmacological treatment with (centrally and peripherally acting) opioids, selective cyclo-oxygenase inhibitors, and NMDA (N-methyl-D-aspartate) receptor antagonists. The aim of the symposium, with its focus on the manifest pain problem, was to improve our knowledge and skill in the understanding and treatment of this large patient category. For patients with rheumatic disorders exacerbated by pain problems, as for other patients, a pain diagnosis is of fundamental importance. This can be achieved by analysis of the social, psychological, physiological and medical factors contributing to the cause and degree of pain and to pain behaviour, and of the extent to which the pain may be nociceptive (i.e., inflammatory, mechanical, or ischaemic in origin), neurogenic or idiopathic. Pain analysis should be followed by individualised treatment focused on the patient's most crucial problems, thus enhancing the prospect of optimal treatment outcome.

Validity of five common manual neck pain provoking tests.

The purpose of the present study was to assess five manual tests for pain provocation of the neck to determine their suitability for epidemiological investigations. To 75 randomly selected men, five manual pain-provoking tests were applied in a single-blind design. Prevalence of reported neck dysfunction, sensitivity, specificity, and positive and negative predicted value for each test were calculated. 22 of the 75 reported present neck pain, while the remainder reported freedom from neck pain for at least one year. Palpation over the facet joints in the cervical spine was found to be the most appropriate screening test to corroborate the replies in self-reported questionnaires on dysfunctions of the neck. The outcome of this test was quite consistent with the reported neck pain. The test of the formina intervertebralia and the upper limb tension test caused pain in almost all subjects with reported neck dysfunctions, though not causing referred pain in the arm as an indication of neurogenous tissue origin, as it was aimed to. Neither the neck rotation test nor the active flexion/extension test was sufficiently provocative to confirm the reported neck pain in these subjects, as both were insufficiently sensitive.

Measurement of pain among electricians with neck dysfunction.

The aim of the study was to develop a pain measurement instrument in Swedish intended for use in epidemiological surveys, and to report the pain assessments of individuals in a working population. The focus was on somato-sensory description in relation to work performance. The material comprised 22 randomly selected electricians attending health checkups, and reporting neck pain during the past week. The pain estimations were made in oral interviews using a specially developed questionnaire. Neck extension and hands above shoulder height caused increased neck pain in all the subjects. The quantitative assessments of present pain showed a limited intensity. To describe the pain quality a wide spectrum of words was used as pain descriptors, but five adjectives were preferred. The more the pain was spread on the pain drawing, the more differentiated was the assessment of its quality. The results concluded that the pain assessment instrument might be useful in epidemiological investigations of musculoskeletal neck dysfunctions.

Patellar forces during isokinetic knee extension.

Eight healthy male subjects performed isokinetic maximum knee extensions from 90 degrees flexion to full extension in a CYBEX n apparatus at two different speeds (30° and 180° s(-1)). Using a planar biomechanical model of the patellofemoral joint, the patellar forces in the sagittal plane were quantified. At the slower speed the patellofemoral compressive force and the suprapatellar tendon force reached values of about 12 bodyweights while the infrapatellar tendon force did not exceed 9 bodyweights. At the faster speed, the corresponding force magnitudes were 7.5 bodyweights and 5.5 bodyweights. The force peaks occurred at the beginning of the extension movement between 65° and 75° of knee flexion and were a function of knee angle and knee extension strength. The magnitude of the patellar forces during isokinetic knee extension of maximum effort were compared to other knee extending activities and were found to be considerably higher than during walking, jogging, and cycling.

An electromyographic study of dental work.

Musculoskeletal disorders are common among dentists, and have been ascribed to the demands of high precision work and sustained static loading in the neck-shoulder region, combined with a flexed and rotated cervical spine. In order to determine muscular load levels during dentistry, activity in neck, shoulder, and arm muscles was recorded using an electromyography technique (EMG). Normalized mean, median, 10th and 90th percentile EMG amplitude levels (% maximal reference contraction, %max-RVC) were calculated during ordinary dental work. Among the muscles investigated, the trapezius muscle on both sides had the highest mean (the right trapezius 9.0% and the left 7.6% of max-RVC) and 10th percentile amplitude levels (both about 2% of max-RVC). The trapezius muscles showed similar myoelectric activity on the right and left side, probably because of similar muscular static load on the both sides. The right extensor carpi radialis muscle had a significantly higher muscular load level than the left one, possibly due to stabilization demands on the dominant wrist during demanding precision work. The infraspinatus muscle had low activity level on both sides, reflecting that the dentists worked with a small degree of arm elevation and external rotation. The dentistry work thus seems to generate relatively high muscular load on both trapezius and dominant extensor-carpi-radialis, and relatively low load on the infraspinatus muscle.

Postural stability in stroke patients: vectorial expression of asymmetry, sway activity and relative sequence of reactive forces.

Bilateral force measurements on the supporting limbs in postural sway while standing still were made to evaluate post-cerebral-vascular accident (CVA) patients during rehabilitation. Normal subjects of the same age group were tested as controls. From the force tracings obtained, three oscillation frequencies were identified, with orders of magnitudes of 7, 1 and 0.1 Hz, respectively, of which the middle frequency, i.e. that corresponding to 1 Hz, was selected for subsequent processing and analysis. These included the determination of relative sequence of the force vectors on both feet and evaluation of timings and amplitudes of the waveforms. Weight-bearing imbalance was defined in the vertical direction to express the difference between the average forces supported by each of the legs. In the horizontal plane, two parameters were defined: sway total activity (SA), to represent the vector summation of the absolute values of the horizontal force components acting on both legs; and asymmetry (ASYM) to express the difference in activities between the two legs. The results presented disclose the reactive force patterns acting on each of the legs of post-CVA hemiplegic individuals, in comparison with normal individuals. Although these forces were shown to act synchronously on both legs, they appeared to be asymmetrical in nature, with a typical vectorial pattern for every individual, which generally differed from that of normal subjects. Sway activity was found to be significantly higher in hemiplegics compared with the normal controls.

Tibiofemoral joint forces during isokinetic knee extension.

Using a Cybex II, eight healthy male subjects performed isokinetic knee extensions at two different speeds (30 and 180 deg/sec) and two different positions of the resistance pad (proximal and distal). A sagittal plane, biomechanical model was used for calculating the magnitude of the tibiofemoral joint compressive and shear forces. The magnitude of isokinetic knee extending moments was found to be significantly lower with the resistance pad placed proximally on the leg instead of distally. The tibiofemoral compressive force was of the same magnitude as the patellar tendon force, with a maximum of 6300 N or close to 9 times body weight (BW). The tibiofemoral shear force changed direction from being negative (tibia tends to move posteriorly in relation to femur) to a positive magnitude of about 700 N or close to 1 BW, indicating that high forces arise in the ACL when the knee is extended more than 60 degrees. The anteriorly directed shear force was lowered considerably by locating the resistance pad to a proximal position on the leg. This model may be used when it is desirable to control stress on the ACL, e.g., in the rehabilitative period after ACL repairs or reconstructions.

Efficiency of pedal forces during ergometer cycling.

The aim of this study was to record the forces applied to the pedal during ergometer cycling and to calculate the effectiveness of these force vectors. Six healthy subjects rode a weight-braked bicycle ergometer at different work loads, pedaling rates, saddle heights, and pedal foot positions. The left lower limb and crank motions were recorded by a cinefilm camera and pedal reaction forces by a Kistler force measuring transducer mounted on the left pedal. The force effectiveness was computed as a ratio between the force tangential to instantaneous direction of pedal movement and the resultant force. The mean force efficiency ratio significantly increased by an increase of the ergometer work load or use of the anterior foot position instead of the posterior. It was not significantly changed due to alterations of the pedaling rate or saddle height.

Joint Motions of the Lower Limb during Ergometer Cycling.

The purpose of the study was to study the utilization of range of motion at the hip, knee, and ankle joints during exercise on a bicycle ergometer. Six healthy subjects biked at different workloads, pedaling rates, saddle heights, and pedal foot positions. The subjects were filmed in the sagittal plane with a cine-film camera at 60 frames/sec. The mean hip range of motion (ROM) during normal cycling was 38 degrees ranging from 32-70 degrees hip flexion. The mean knee ROM was 66 degrees ranging from 46-112 degrees knee flexion, and the ankle ROM was 24 degrees ranging from 2 degrees plantarflexion to 22 degrees dorsiflexion. The hip, knee, and ankle joint motions were influenced by changes of the saddle height or pedal foot position. Different workloads had a small but statistically significant influence on the joint motions while different pedaling rates did not significantly change the lower limb joint motions. The range of motion utilized during cycling is approximately equal to, but more flexed compared to level walking and stair walking. The most effective way of increasing the ROM and obtaining more extension of the lower limb joints is to change the saddle height.J Orthop Sports Phys Ther 1988;9(8):273-278.

Knee and ankle joint forces during steps and jumps down from two different heights.

Two healthy subjects were filmed on TV-video when performing 14 different steps and jumps from two different heights (0·20 m and 0·43 m) onto two Kistler force platforms that recorded the reaction forces. The ankle and knee load moments and joint forces were calculated using a sagittal plane semi-dynamic biomechanical model. Steps with the ball of the foot from the lower height induced a vertical ground reaction force (Fz) close to 1 body weight (bw) and around 2 bw from the greater height. From the greater height the knee moments for the majority of the step-downs studied were about 100 Nm, which gave knee joint compressive forces of 4-7 bw. The ankle was exposed to loads of similar magnitude but not so much influenced by step height. The reasons why patients with knee pain prefer performing backward step-downs are discussed.

Patellofemoral joint forces during ergometric cycling.

We estimated the patellofemoral joint forces generated during pedaling on a bicycle ergometer. Our calculations were based on measurements from a force transducer mounted on the pedal, 16-mm cine-film sequences, and biomechanical models of the cycling motion and of the patellofemoral joint. Six healthy male subjects cycled at different work loads, pedaling rates, saddle heights, and pedal foot positions. The maximum patellofemoral compressive force was 905 N (1.3 times body weight [BW]) when cycling with an anterior foot position at 120 W, 60 rpm, and middle saddle height. The mean peak compressive force between the quadriceps tendon and the intercondylar groove was 295 N (0.4 BW), and the patellar-tendon and quadriceps-tendon strain forces were 661 N (0.9 BW) and 938 N (1.3 BW), respectively. The patellofemoral joint forces were increased with increased work load or decreased saddle height. Different pedaling rates or foot positions did not significantly change these forces.

Tibiofemoral joint forces during ergometer cycling.

Six healthy subjects pedaled on a weight-braked bicycle ergometer at different workloads, pedaling rates, saddle heights, and pedal foot positions. The subjects were filmed with a cine-film camera and pedal reaction forces were recorded from a force transducer mounted on the left pedal. Net knee moments were calculated using a dynamic model, and the tibiofemoral shear and compressive force magnitudes were calculated using a biomechanical model of the knee. During cycling at 120 W, 60 rpm, midsaddle height, and anterior pedal foot position, the mean peak tibiofemoral compressive force was 812 N [1.2 times body weight (BW)]. The maximum anteriorly directed tibiofemoral shear force was found to be low (37 N). The compressive and shear forces were significantly increased by an increased ergometer workload. The pedaling rate had no influence on the tibiofemoral force magnitudes. The stress on the ACL was low and could be further decreased by use of the anterior foot position instead of the posterior.