Biomedical subjects

E P Takala

Publications and source records attributed to E P Takala.

At least 19 recordsLinked to original sources

PubMed2001

A dynamic model of the forearm including fatigue.

A biomechanical model of the forearm, consisting of 61 muscle-tendon systems or tendons and 8 sections, is presented. The model can be used to calculate the muscle forces when resultant of the external forces and the motion is known. Calculations are based on constraints of muscle forces, joint forces, contact forces, and tendon junctions, and a load sharing principle telling which of the feasible solutions are likely and which are not. Fatigue is accounted for by updating the upper limits of the muscle forces according to the loading history. As an example, the model is used to predict the load sharing between the fingers when they are pressed against a table with a given total force.

Biomechanical Phenomena↗

PubMed2001

Physical exercise and musculoskeletal pain among forest industry workers.

The study investigated the relations between physical exercise and musculoskeletal pain among forest industry workers. We studied a population of 3312 Finnish forest industry workers, who replied to a questionnaire survey in 1994 (response rate 77%). The outcome variables in this cross-sectional study were the number of days with pain in the low back, neck, shoulder and knee during the preceding 12 months. Multivariable logistic regression models were used in statistical analyses. Active walkers had more sciatic pain, active volleyball players had more shoulder pain and those who practiced trekking actively had more knee pain than those who practiced these activities less. The risk of shoulder pain was more than three times higher for those who played volleyball actively compared to those who played less. In addition, age, mental stress and work-related physical loading were strongly associated with musculoskeletal pain. When studying the relations between physical exercise and musculoskeletal pain in a working population, it is important to not only detect the general physical activity but also to specify the different modes of exercise. In addition, the other factors which are strongly related to pain (such as mental stress and work-related physical loading) should be taken into account.

Adult↗

PubMed2001

Longitudinal study on work related and individual risk factors affecting radiating neck pain.

OBJECTIVES: To study the effects of work related and individual factors affecting radiating neck pain. METHODS: A longitudinal study was carried out with repeated measurements. A total of 5180 Finnish forest industry workers replied to a questionnaire survey in 1992 (response rate 75%). Response rates to follow up questionnaires in 1993, 1994, and 1995 were 83%, 77%, and 90%, respectively. The outcome variable was the number of days with radiating neck pain during the preceding 12 months with three levels (<8, 8-30, >30 days). The generalised estimating equations method was used to fit a marginal model and a transition model was used in a predictive analysis. RESULTS: Items showing associations with radiating neck pain in both analyses were sex, age, body mass index, smoking, duration of work with a hand above shoulder level, mental stress, and other musculoskeletal pains. In the transition model, radiating neck pain in a previous questionnaire was included in the model. Although it was a strong predictor, the variables already mentioned retained their significance. CONCLUSION: Programmes targeted to reduce physical load at work, mental stress, being overweight, and smoking could potentially prevent radiating neck pain.

Adult↗

PubMed2001

A prospective study of work related factors and physical exercise as predictors of shoulder pain.

OBJECTIVES: To evaluate the effects of work related and individual factors as well as physical activity and sports on the incidence and persistence of shoulder pain among forestry workers. METHODS: Workers in a large Finnish forestry company replied to a questionnaire (a modified version of the Nordic questionnaire) on musculoskeletal pain and its possible risk factors for 4 consecutive years 1992-5. This 1 year follow up study covers the time 1994-5. Year 1994 was chosen as baseline because in that year the questionnaire contained for the first time more detailed questions about different sports. The response rate in 1995 was 90%. The effects of the predictors on 1 year incidence and persistence of shoulder pain were studied with multivariate logistic regression modelling. RESULTS: At baseline, 2094 subjects had been free of shoulder pain during the preceding 12 months. After 1 year, 14% (n=285) reported having mild or severe shoulder pain. Higher age, obesity, and mental stress as well as physically strenuous work and working with trunk forward flexed or with a hand above shoulder level increased the risk of incident shoulder pain. Of the different sports activities, dancing increased the risk of incident pain whereas jogging decreased the risk significantly. Of those 419 workers who had severe shoulder pain at baseline, 55% (n=230) still had severe pain 1 year later. Higher age, overload at work, and working with a hand above shoulder level increased the risk of persistent severe shoulder pain whereas cross country skiing and general sports activity decreased the risk. CONCLUSION: Our results support the current view that shoulder pain is the result of many factors, including occupational and individual factors. In this longitudinal study, physical work with a heavy load, awkward work postures, mental stress, and obesity were the risk factors at which preventive measures could be aimed. As a new finding, physical exercise had more protective than impairing effects on the shoulders.

Adult↗

PubMed2000

Do functional tests predict low back pain?

STUDY DESIGN: A cohort of 307 nonsymptomatic workers and another cohort of 123 workers with previous episodes of low back pain were followed up for 2 years. The outcomes were measured by symptoms, medical consultations, and sick leaves due to low back disorders. OBJECTIVES: To study the predictive value of a set of tests measuring the physical performance of the back in a working population. The hypothesis was that subjects with poor functional capacity are liable to back disorders. SUMMARY OF BACKGROUND DATA: Reduced functional performance has been associated with back pain. There are few data to show whether reduced functional capacity is a cause or a consequence of pain. METHODS: Mobility of the trunk in forward and side bending, maximal isokinetic trunk extension, flexion and lifting strength, and static endurance of back extension were measured. Standing balance and foot reaction time were recorded with a force plate. Clinical tests for the provocation of back or leg pain were performed. Gender, workload, age, and anthropometrics were managed as potential confounders in the analysis. RESULTS: Marked overlapping was seen in the measures of the subjects with different outcomes. Among the nonsymptomatic subjects, low performance in tests of mobility and standing balance was associated with future back disorders. Among workers with previous episodes of back pain, low isokinetic extension strength, poor standing balance, and positive clinical signs predicted future pain. CONCLUSIONS: Some associations were found between the functional tests and future low back pain. The wide variation in the results questions the value of the tests in health examinations (e.g., in screening or surveillance of low back disorders).

Adult↗

PubMed2000

Active treatment of chronic neck pain: a prospective randomized intervention.

STUDY DESIGN: A randomized comparative study with single-blind outcome assessments. OBJECTIVES: To compare the efficacy of a multimodal treatment emphasizing proprioceptive training (ACTIVE) with activated home exercises (HOME) and recommendation of exercise (CONTROL) in patients with nonspecific chronic neck pain. SUMMARY OF BACKGROUND DATA: The efficacy of active exercises and passive physiotherapy for neck trouble has been somewhat disappointing in the previous few studies. METHODS: Seventy-six patients (22 men, 54 women) with chronic, nonspecific neck pain participated. Sixty-two participated the 1-year follow-up. Subjective pain and disability, cervical ranges of motion, and pressure pain threshold in the shoulder region were measured at baseline, at 3 months, and at 12 months. The ACTIVE treatment consisted of 24 sessions of proprioceptive exercises, relaxation, and behavioral support. The HOME regimen included a neck lecture and two sessions of practical training for home exercises and instructions for maintaining a diary of progress. The CONTROL treatment included a lecture regarding care of the neck with a recommendation to exercise. RESULTS: The average self-experienced total benefit was highest in the ACTIVE group, and the HOME group rated over the CONTROL group (P < 0.001). Differences between the groups in favor of the ACTIVE treatment were recorded in reduction of neck symptoms and improvements in general health and self-experienced working ability (P < 0.01-0.03). Changes in measures of mobility and pressure pain threshold were minor. CONCLUSIONS: Regarding self-experienced benefit, the multimodal treatment was more efficacious than activated home exercises that were clearly more efficacious than just advising. No major differences were noted in objective measurements of cervical function between the groups, but the content validity of these assessments in chronic neck trouble can be questioned.

Adult↗

PubMed2000

Effects of two ergonomic aids on the usability of an in-line screwdriver.

We assessed the effects of two ergonomic aids on the usability of an in-line screwdriver. The simple aids considered were a hand support and a sleeve which softened the handle. In an experiment, 15 subjects drove screws into horizontal plywood plates with four combinations of a screwdriver and an ergonomic aid. The activities of four forearm muscles (EMG) and the force acting on the screw were measured. The subjects rated the properties of the tools as regards physical exertion, the ease of taking hold of the tool, comfort of the grip, and the surface texture. The hand support and the sleeve had positive effects on the subjective perception of exertion and the surface texture, respectively. Differences in EMG and thrust force along the shaft of the screwdriver handle were found to be too small for reliable deductions in the effects of the ergonomic aids.

Adult↗

PubMed2000

Assessment of duration and frequency of work tasks by telephone interview: reproducibility and validity.

Quantitative estimation of physical work load requires breakdown of jobs into smaller entities. The objective was to study the inter-rater reproducibility of the contents, frequency and duration of work tasks assessed by telephone interview. Two researchers interviewed 18 industrial workers with an interval of from 2 to 3 weeks in a balanced and blinded design. Altogether 114 tasks were identified, 68 of which were recorded by both interviewers. The tasks were classified into regularly occurring (n = 34) and occasional (n = 80). The outcome was the total duration of the tasks per day computed from the data on frequency and duration. Validity of the interview was studied against prestructured diaries filled in by nine workers. The interviewers' assessments of the overall contents of the tasks were rated as 'similar' or 'very similar' for 17 of the 18 workers. Both interviewers detected all 34 regularly occurring tasks. The intraclass correlation coefficient (ICC) of the total duration between the interviewers was 0.81 for regularly occurring tasks. ICCs of the total duration between the diary and the two interviewers were 0.90 and 0.91. However, in many cases the workers could not give a numerical value for duration or frequency. A telephone interview can be used as a first step in exposure assessment in epidemiological studies on risk factors of musculoskeletal disorders. These results show that a single telephone interview can give reproducible and valid information of the frequency and duration of tasks occurring daily. For occasional tasks interview methods should be developed further.

Adult↗

PubMed2000

"A good future for deaf children": a five-year sign language intervention project.

Deaf preschoolers and hearing family members learned sign language in a 5-year intervention project. Once weekly, each child met with a teacher who was deaf. Parents, siblings, and other relatives met about once monthly to study sign language, and all families in the project signed together about twice yearly. The present study addressed four questions asked of parents about the project: (a) How did the children learn to sign? (b) Did both the parents and the children benefit from the project? (c) What was the position of sign language in the family? (d) Did the project have some impact on the family's social network? The families indicated satisfaction with the project; they learned to sign and their social networks expanded. Parents favored bilingual education: Sign language was the main language but learning Finnish was also important. Learning sign language was not easy, especially for the fathers. The families that were most actively involved in the lessons learned the most.

Adult↗

PubMed1998

Standardized physical examination protocol for low back disorders: feasibility of use and validity of symptoms and signs.

A standardized examination protocol was developed for the assessment of low back disorders in primary care. The protocol was found feasible in the occupational health service setting. The interexaminer repeatability between an occupational physician and an occupational physiotherapist was good for most items. The predictive validity of different symptoms and signs was investigated with regard to future sick leaves due to low back disorders. Relief of pain when lying, severe trouble at work caused by pain, continuous pain, and pain in the leg or numbness or diminished sensitivity in the foot predicted sick leaves. Of physical signs, pain in the low back or buttock during lateral flexion and a side difference > or = 20 degrees in the straight-leg-raising angle were predictors for sick leaves. The predictive validity of the protocol items should be tested in another patient population before conclusions can be drawn concerning the external validity of our results.

Adult↗

PubMed1998

Do psychological factors predict changes in musculoskeletal pain? A prospective, two-year follow-up study of a working population.

Our aim was to determine the predictive value of some psychometric instruments for the development and persistence of musculoskeletal pain. In 452 subjects, pain in the shoulder, neck, and low back during the preceding year was assessed at baseline, one year, and two years' follow-up. Psychological distress, depression, self-efficacy beliefs, subjective work prognosis, disability, and work characteristics were assessed at baseline. The best predictor of future pain was disability. The psychometric measures did not predict changes in pain. The explanatory power of the variables in the multivariate analyses was low. Perceived disability in persons with musculoskeletal symptoms should be acknowledged early. The traditional research paradigm focusing on a few hypothetically relevant variables does not take into account the reflective, dynamic, reciprocal nature of human behavior during the process of recovery from or development of a pain problem.

Adult↗

PubMed1997

Effects of changes in work methods on musculoskeletal load. An intervention study in the trailer assembly.

The purpose of this case study was to identify the work cycles imposing high loads on the upper limb and low-back among trailer assembly workers for an ergonomic intervention. Several changes in work methods, tools and work organisation were implemented. The number of repetitions of fundamental work cycles and wrist posture were recorded from the video. Exposure imposed on the upper extremity in driving screws and drilling was computed based on experiments on force and time requirements. In lifting or carrying, the dose imposed on the low-back was computed based on the load moment on the L5/S1 disk and duration of the cycle. It was shown that after the intervention most workers worked less with deviated wrist and the cumulative exposure on the upper extremity was lower in furniture fixing tasks. Lifting with twisted torso was reduced. It was concluded that with relatively simple and low-cost solutions exposure to important risk factors of upper extremity and low-back disorders could be reduced.

Adult↗

PubMed1997

Validation of Portable Ergonomic Observation (PEO) method using optoelectronic and video recordings.

The validity of the 'Portable Ergonomic Observation' method (PEO) was investigated against posture measurements based on continuous optoelectronic and video recordings made simultaneously with the observation. Work postures and actions during different frequently changing tasks were analyzed using both methods. In general, a high agreement between measured and observed data was achieved for the duration of clearly identifiable sustained postures and actions (such as repetitive movements of hands when typing), as well as for the frequency of clearly distinguishable actions (such as lifts). The agreement between observations and measurements was low for neck postures. In dynamic tasks the agreement was generally low. This was probably because of high levels of simultaneous information for the observer. No improvement in the agreement between measured and observed events could be achieved by leaving parts of the PEO categories unobserved at a time. Playback of video tapes to observe each category separately would increase the reliability of the observations but at the expense of increased time for the analysis.

Ergonomics↗

PubMed1996

A static shoulder model based on a time-dependent criterion for load sharing between synergistic muscles.

A static shoulder model including a novel muscular synergy principle for computing load sharing between the shoulder muscles is presented. This principle is feasible especially when analysing endurance-type activities. According to the principle, time elapsed from the start of the activity decreases the allowable muscle stress levels on the basis of the stress-endurance time curves of individual muscles. At low load levels the sum of the squared forces is minimized. At higher load levels the increase in the stress levels of individual muscles is counteracted in order to prevent fatigue. In the model the direction of the contact force in the glenohumeral joint is constrained. The stiffness of the shoulder can also be constrained to produce more muscular co-contraction in tasks with high precision demands.

Biomechanical Phenomena↗

PubMed1996

Validity of self-reported physical work load in epidemiologic studies on musculoskeletal disorders.

OBJECTIVES: This study assessed the validity of self-reported physical work load by questionnaire and logbook against task analysis and observation. It also investigated factors (job type and low-back or neck pain) affecting the self-assessment of physical work load and compared the assessments between the questionnaire and the logbook. METHODS: A self-administered questionnaire including 10 questions (ordinal scales) on physical work load and musculoskeletal symptoms was filled out by 2756 men in the forest industry. From this population, 36 men were selected for task analysis and observation. Logbooks including 10 continuous variables were analyzed for 386 men. RESULTS: The Spearman rank correlation coefficients between the self-assessments and observations for the frequency of manual handling, duration of trunk flexion, neck rotation, hand above shoulder level, and squatting or kneeling ranged between 0.42 and 0.55. The correlation coefficients for the questionnaire items were higher in general, and the accuracy better, for those with no low-back pain than for those with pain. The duration of trunk flexion, neck flexion and hand above shoulder level was overestimated in the questionnaires and less so in the logbooks. CONCLUSIONS: Self-administered questionnaires may help to classify groups with heterogeneous occupational tasks according to some work-load factors. The accuracy of the assessments is not good for studying quantitative exposure-effect relationships, however. The logbook method might give more valid information. The perception of musculoskeletal pain may bias the self-assessment of work load.

Adult↗

PubMed1995

Load-sharing patterns in the shoulder during isometric flexion tasks.

Patterns of load-sharing between the shoulder muscles during isometric flexion tasks were studied by using both a biomechanical shoulder model and electromyographic (EMG) recordings of ten subjects. The effect of changes in several model parameters and shoulder stiffness constraints on the predicted load-sharing patterns were studied, while the arm position, hand load and precision requirements of the tasks were varied. The results calculated using the model were, when compared to the EMG recordings, plausible predicting a high level of synergistic contraction of muscles of the shoulder muscles during flexion tasks. The trends of the model-predicted muscle forces corresponded well to the EMG recordings. At low hand load levels the increasing of the shoulder stiffness strongly increased the muscle force levels, thus increasing also the level of synergistic contraction of muscles. At higher load levels the increase in the muscle forces was not so high, because the model predicted a high level of simultaneous contraction of muscles already at a low level of shoulder stiffness. Cluster analysis of the EMG recordings revealed large inter-individual differences in the load distribution patterns during flexion tasks. The constraint angle of the glenohumeral joint contact force direction was found to be an important model parameter affecting both the predicted forces and the maximum force production ability of the shoulder.

Adult↗

PubMed1995

Assessment of depression in chronic musculoskeletal pain patients.

OBJECTIVE: To analyze how the cognitive, affective, and somatic-vegetative symptoms of depression included in the modified Zung Self-Rating Depression Scale (ZSDS) relate to pain severity. SUBJECTS: Three groups of subjects were compared. The "no pain" group (n = 64) reported no musculoskeletal symptoms during the preceding year, the "low pain" group (n = 119) had a pain rating of < or = 4, and the "high pain" group (n = 137) had a rating of > or = 5 on a numerical pain rating scale (0-10). METHODS: Sum scores of the ZSDS and means of separate items in the three subgroups were compared. Factor analyses were performed to evaluate the structure of the ZSDS, and differences between subgroups on weighted factor scores were analyzed. RESULTS: The "high pain" group differed statistically significantly from both other groups on the sum score and on most of the items. Comparison of weighted factor scores in a three-factor solution revealed that in Factor I, "Psychic Energy," the "high pain" group differed from both other groups. In Factor II, "Despair," no differences between groups were found, while in Factor III, "Sleep problems," statistically significant differences were found between all subgroups; more severe pain was associated with more sleep problems, fatigue, and restlessness. CONCLUSION: ZSDS items describing symptoms which could be a consequence of the pain problem (e.g., sleep problems) are clearly related more to pain severity than other indicators of depression--e.g., feelings of hopelessness. A diagnosis of depression based on a sum score of an inventory which contains somatic-vegetative signs of depression may lead to an overestimation of depression in chronic musculoskeletal pain patients. in chronic musculoskeletal pain patients.

Adult↗

PubMed1994

Does group gymnastics at the workplace help in neck pain? A controlled study.

The effects of group gymnastics on neck pain were studied among 44 women in a printing company. A randomized cross-over design was used with two groups matched according to the work task, frequency of symptoms, and age. The treatment consisted of gymnastics for 45 min once a week for 10 weeks. Neck pain was rated by visual analogue scale and pressure pain sensitivity of the neck muscles was measured with an algometer. The results showed no clear effects of the group gymnastics program. An equal and significant reduction in pain ratings was seen in both groups after the first intervention in the spring. Recurrence of symptoms was seen in both groups in September, and no significant reduction in pain occurred during the second intervention in the autumn. The results suggest a seasonal variation in neck symptoms which has to be considered when planning or evaluating intervention studies.

Adult↗