A field experiment comparing mechanical demands of two pruners for flower cutting

Manual flower cutting requires repetitive forceful movements that may explain the high incidence of upper-extremity MSDs among workers of the Colombian flower industry. Force demands may be caused by the use of pruners that have not been designed for Colombian workers. We conducted a repeated measures field experimental study (n=16, 69% women, 20 to 60 years old) to compare the mechanical demands during rose cutting of two different pruners (Traditional vs. alternative pruner) at two different cutting heights (elbow vs. over-shoulder). Demands included the perceived comfort, perceived effort and upper limb's muscular activity and posture. Workers perceived their traditional pruner as more comfortable but requiring more effort than the prototype tool. No benefits were observed regarding ulnar deviation with the alternative pruner. The wrist extension and related muscular activity of the wrist extensors were higher with the prototype pruner. The prototype pruner resulted in reduced muscular load of the wrist flexors; the biceps when working at the elbow height; and the deltoids when working at the shoulder height. However, Moderate results may be explained by the lack of time for workers' adaptation to the alternative tool. New design developments must focus on reducing extension and ulnar deviation of the wrist.     

Distal upper extremity musculoskeletal risk factors associated with colonoscopy

Gastroenterologists are at increased risk for developing recurrent thumb, hand, and elbow pain due to colonoscopy procedures. We evaluated forearm muscle loads and wrist postures during routine colonoscopy (N=12 gastroenterologists) to understand distal upper extremity musculoskeletal risk factors associated with the 4 different subtasks of colonoscopy. Bilateral forearm extensor carpiradialis (ECR) and flexor digitorum superficialis (FDS) surface electromyography and bilateral wrist postures were recorded continuously. The mean duration of colonoscopy was 24.2 (± 12.1) minutes and was dominated by the withdrawal subtask [13.7 (± 8.8) min] followed by right colon insertion [5.8 (± 4.8) min], left colon insertion [3.5 (± 3.1) min], and retroflexion [1.2 (± 2.1) min]. Median (APDF50) and peak (APDF90) left forearm muscle activity was significantly greater than right forearm muscle activity across all subtasks. Median and peak ECR muscle activity was significantly greater during the left and right colon insertion subtasks compared to retroflexion. Both wrists were predominantly in wrist extension during all phases of colonoscopy. The left forearm muscle activity was higher than right forearm activity due to differences in wrist posture and grip force. The risk factors for the left hand may be reduced with alternative designs and support mechanisms for the colonoscope head.     

Reliability and effects of muscular pretension on isometric strength of older adults

There were two objectives to this study: (a) to determine the reliability of measuring isometric maximum torque (MT) and maximum rate of torque development (MRTD) of the knee extensor and flexor muscles and (b) to assess the effects of different muscular pretensions on MT and MRTD of older adults. Maximum strength of 35 untrained healthy older adults (aged 66.9?±?6.6 years; height 1.72?±?0.07 m; weight 75.2?±?9.6 kg) was measured. Strength measurement was performed with the Dr. Wolff ISO Check using a piezo-electric force transducer. MT intra-day coefficient of variation (CV) was between 3.30 and 12.40 % for both measurement sessions. Intraclass correlation coefficients (ICC) ranging from 0.71 to 0.99 showed good relative reliability. MT test–retest reliability (between sessions 1 and 2) of knee extension reached a CV between 7.10 and 9.30 % and high ICC values. The measurement of the knee flexion achieved an acceptable CV (9.40 %) at 40 % muscular pretension. MRTD was negatively influenced by muscular pretension (p <0.05). In conclusion, MT could be measured reliably over different trials using isometric strength measurement. The test–retest reliability was acceptable at knee extension with 10 to 40 % muscular pretension and with 40 % muscular pretension at knee flexion. A higher muscular pretension has no impact on MT but decreases MRTD in older adults.     

Using walker during walking: a pilot study for health elder

Walker operation completely relies on the walker handle, however most marketed walkers possess two horizontal handles. Several researchers have suggested that horizontal handles might lead to wrist injury. Therefore, the purpose of this study is to assess the relevant design aspects of walker for elderly people. 28 elders participated in this study; when the experiment was started, subject walked on the tile for 3 meter distance twice by using walker. Data for analysis were selected at the corresponding wrist deviation and vertical force. The results showed that during walker using, the mean wrist deviation was greater than zero. The largest vertical force is significantly larger than the smallest one, and different wrist deviation occurred at three phases, the largest wrist deviation while raising walker is larger than the smallest one, however, no significant different was found between the largest and smallest wrist deviation while pressing walker. No significant correlation occurred between weight and wrist deviation. The correlation between weight and vertical force was significantly positive. With wrist deviation walker use may cause injury to upper-limb, however wrists remain in a neutral position during hand movement to prevent damage. The findings of this study should improve the design of walker handles to reduce the wrist deviations of users.     

Ergonomics of novices and experts during simulated endotracheal intubation

Endotracheal Intubation (ETI) is an airway procedure commonly used to secure the airway for a variety of medical conditions. Proficiency in ETI procedures requires significant clinical experience and insufficient data currently exists describing the physical ergonomics of successful direct laryngoscopy. The research objectives of this study were to examine how ETI time, error and practitioner biomechanics varied among clinical experience levels and hospital bed heights. The participant population included novice and expert personnel, differentiated by their exposure to ETI procedures. Participants used a standard laryngoscope and blade to perform ETI trials on an airway manikin trainer at predesigned hospital bed heights. Participants were evaluated based on ETI time and accuracy, as well as wrist postures and muscle utilization. Hospital bed height did not affect task completion time, error rates or muscle utilization. Expert participants exhibited less ulnar deviation and forearm supination during task trials, as well as a higher utilization of the bicep brachii and anterior deltoid muscles. Expert grasped instrumentation differently, requiring less wrist manipulation required to achieve ideal instrument positions. By encouraging ergonomic best-practices in hand and arm postures during ETI training, the opportunity exists to improve patient safety and reduce the learning curve associated with ETI procedures.     

Therapeutic Effects of an Outdoor Activity Program on Nursing Home Residents with Dementia

Abstract

Objective: The purpose of this one-year pilot study was to obtain preliminary information on the effects of an outdoor activity program, in comparison to an indoor activity program, on sleep and behavior in nursing home residents with dementia. Structured activity programs have been shown to improve dementia-related behavior problems, and there are some indications that improved behavior is associated with improved sleep. Previous research has shown that sleep disturbance is common in nursing home residents, and that limited exposure to light bright enough to entrain circadian rhythms contributes to their sleep problems. Thus, we expected to see improvements in behavior in both the outdoor and indoor activity groups, but improvements in sleep in the outdoor activity group only.

Methodology: A two-group (outdoor program, indoor program) two phase (baseline, intervention) design was used. Subjects were randomized to the outdoor or indoor program groups. Sleep and behavior disturbance were assessed over a 10-day period at baseline (usual activity conditions, which were expected to include little or no time spent outdoors) and at intervention (daily structured activity program offered outdoors or indoors). Sleep was assessed with wrist actigraphs with photocells, which also allowed for monitoring of light exposure. Behavior disturbance was assessed with the Cohen-Mansfield Agitation Inventory. Both activity programs were offered Monday-Friday over a 2 week period, included similar content and were offered by research project staff. The analytical approach emphasized primary changes between baseline and intervention measures of sleep and behavioral symptoms in the two activity groups. Because this was a pilot study, the significance level was set a priori at p< 0.10.

Findings: The outdoor activity group experienced significant improvements in maximum sleep duration. Both groups showed significant improvements in total sleep minutes. There also was a significant improvement in verbal agitation in the outdoor activity group.     

Multi dimensional system for evaluating preventive program for upper extremity disorders among computer operators

Typing is associated with musculoskeletal complaints (MSCs), caused by multiple risk factors. Although a wide variety of ergonomic intervention programs were conducted to reduce risk factors and MSC's, only few of them were found evidence based. This study aimed to test the efficacy of a workplace intervention in reducing MSC's among computer workers. 66 computer workers were assigned randomly to one of three intervention programs: ergonomic intervention including biofeedback, intervention without biofeedback and control group without intervention. The efficacy was tested by advanced assessment including; pain location and severity, posture at work, upper extremity 3D kinematics, muscle activity and psychosocial status. Working hypothesis; significant score differences will be found between the study groups which underwent ergonomic intervention and the control group on the following measures: pain complaints, upper extremity kinematics, muscle activity and psychosocial status. Significant differences were found between pre and post intervention and between research groups and the control group in pain, posture and motion. The ergonomic intervention with biofeedback had no unique contribution in comparison to other interventions. In conclusion; the proposed intervention program was found efficient for reducing pain among computer workers.     

Ergonomic evaluation of novel tool for snap-off the neck of ampoule

Needlestick and Sharps Injuries (NSI) represent an important workplace issue in contemporary health care. Present study provided the new method to snap-off the neck of sealed ampoule. The idea of novel opener tool is prepare the grinding slice inside rubber ring, so users could put the ampoule inside the rubber ring and then rotated the rubber ring to snap-off the neck of ampoule. The purpose of present study was evaluated the methods of snap-off and sizes of ampoule on forearm muscle activities, wrist postures and performance. The pronator teres muscle were heavier load as increased the sizes of ampoule. For performance analysis, Duncan's multiple range tests indicated that time of snap-off were longer in 10 ml and 20 ml of ampoule. The EMG of pronator teres muscle was significantly affected by methods of snap-off. Duncan's multiple range tests indicated that lower load was experienced on forearm muscles while using grinding slice with glove. For wrist posture, the ranges of motion for wrist were significant lower while using the novel tool. Present study provided the novel tool effectively to snap-off the ampoule to decrease forearm workload and sharp injuries.     

Assessment of physical exposures and comparison of exposure definitions in a repetitive sawmill occupation: trim-saw operator

This paper describes the physical exposures required to perform a sawmill job associated with a high incidence of upper extremity musculoskeletal injury. Exposure variables are described by multiple posture, exertion and frequency definitions and the comparability of those definitions are examined. Effective industrial prevention efforts require an accurate assessment of risk. Surface electromyography and electrogoniometry were used to quantify the physical exposures of 29 trim-saw operators in four sawmill facilities. Average wrist ranges of motion of 32, 57 and 58 degrees in wrist radial/ulnar deviation, flexion/extension and pronation/supination respectively were required to perform the job. Defining wrist range of motion by the peak postures observed versus those required to perform the primary task resulted in significantly different ranges of motion (p<0.05). Job performance required an average of 33% of maximum voluntary contraction. Repetitions per day ranged from 3,549 to 14,460. Percentage of maximum voluntary contraction was not associated with psychophysical measures of exertion.     

Effectiveness of an educational intervention to increase knowledge and reduce use of risky behaviors associated with cumulative trauma in office workers

OBJECTIVE: This pilot project assessed the effectiveness of an intervention to increase knowledge and reduce risky behaviors related to cumulative trauma disorders (CTD) in office workers. STUDY DESIGN: All 124 employees from the administrative offices of a health maintenance organization were invited to participate. Subjects were followed across time using an identification number. Data were collected via questionnaire in June 1994 (pretest1) (N=84), August 1994 (pretest II) (N= 63) and September 1995 (posttest) (N=40). The yearlong intervention focused on functional activities to prevent CTD. RESULTS: of chi-square analyses for the 40 subjects who completed all surveys indicated this intervention significantly increased overall knowledge of CTD (p =.002). Significant changes in self-reported hand/wrist (p =.016) and neck/shoulder (p =.003) posture were also found. CONCLUSIONS: This study is a first step in identifying effective educational interventions to increase knowledge and reduce risk factors related to CTD in office workers.     

Peer 2 Peer: Efficacy of a Course-Based Peer Education Intervention to Increase Physical Activity Among College Students

Abstract

There are few physical activity (PA) interventions in higher education, and they have been only minimally effective. Objective: To determine if a course-based, peer education intervention was associated with increases in PA and physical fitness. Participants: Participants were 178 students enrolled in a personal health class during the 2007–2008 academic year. Methods: A quasi-experimental design was used to assess the effect of the intervention. Repeated measures analysis of covariance was employed to test the impact of the intervention on students’ PA, body composition, waist-to-hip ratio, cardiovascular fitness, flexibility, and muscular strength. Results: Women in the treatment group classified as “Inactive” at baseline increased PA, whereas “Inactive” control women had reductions in PA. Women in the treatment group who were “Active” at baseline reduced their waist-to-hip ratio and increased flexibility. There were no differences by treatment group among men. Conclusions: The intervention was effective in improving PA and physical fitness among college women.     

Gender-related differences in physical performance among seniors

This study examined gender differences in balance, gait, and muscle performance in seniors and identified gender-specific factors contributing to physical performance. Forty (20 men, 20 women) healthy, community-dwelling seniors (74.5 +/- 5.3 years) participated. Limits of stability, gait speed, lower limb flexor and extensor isokinetic concentric peak torques, self-reported activity level, and balance confidence were measured. No gender differences were detected in gait speed, limits of stability when normalized to height, activity level, or balance confidence (p = .188). Women were weaker than men (p = .007), even after controlling for weight and body-mass index, suggesting that other gender-related factors contribute to strength. Gender accounted for 18-46% of the variance in strength and served as a modifier of the relationship between activity level and strength in some muscle groups. The primary factors relating to gender-specific strength was activity level in men and body weight in women.     

Direct observation of computer workplace risk factors of college students

Recently, researchers have reported high musculoskeletal symptom prevalence at several US colleges. Since ergonomic interventions have been shown to prevent and reduce disability, it is important to identify the risk factors for developing symptoms among college students. A nested case-control study was completed to determine computer-related ergonomic risks associated with musculoskeletal symptoms. A trained observer completed ergonomic assessments on 52 randomly selected cases and controls. More than 75 percent (cases and controls combined) of the population was exposed to nine potential postural strains including: arms not along side during keying or mousing; lower back not supported; not having chair accessories; computer monitor not adjustable; mouse being too high or low; hand/wrist/forearm in contact with the desk edge; lack of wrist support; and keyboard not being adjustable. Cases and controls were equally likely to have substantially elevated risks but because the sample was small and lacked power, no risks were statistically significant. Since many known risk factors were prevalent in cases and controls, more research is required to evaluate and prevent injury in this population.     

Long-term effects of forearm support: computer users working at conventional desks

Recent research has demonstrated that forearm support might be preferable to working in the traditional "floating" posture for computer users. A previous field study in a call centre reported a significant decrease in discomfort following 12 weeks of using a conventional desk for forearm support. The aim of this follow up study was to determine the long-term effect (21 months post intervention) of forearm support on reported musculoskeletal discomfort in the previous sample of intensive computer users. METHODS: The follow-up sample consisted of 33 females and 2 males (59% of original group). Data were collected via self-report questionnaires and workstation assessments. RESULTS: Despite a significant reduction in discomfort for most body regions following the initial intervention, the only significant decrease in discomfort over 21 months was for the neck. Reported discomfort for all other body regions had decreased, apart from the shoulder in which there was a reported increase in discomfort. The results of this follow up study indicate that forearm support has a positive effect on the reduction of neck discomfort. The increase in shoulder discomfort indicates that a concave desk may be preferable to the conventional desk if the forearm support posture is to be adopted.     

Long periods with uninterrupted muscle activity related to neck and shoulder pain

The aim was to analyze the relationship between periods with uninterrupted neck muscle activity for ≥ 4 min and neck and shoulder pain. The trapezius muscle activity was recorded bilaterally on 40 young workers and students during a full shift. Neck and shoulder pain, mechanical work load and decision control were reported at the same time as the muscle activity recording and 6 months later. A dose-response relationship was found between uninterrupted muscle activity and neck and shoulder pain, with a ten-fold higher risk for the group with more than half, compared to less than a third, of the shift with uninterrupted muscle activity. Self-reported mechanical work load showed a small but protective effect related to pain. Gender and decision control did not emerge as important risk factors in this model. In conclusion, this study indicates that work or other exposures that contains long periods with uninterrupted neck muscle activity of 4 min duration or longer should be minimized to reduce risk of neck and shoulder pain.     

Children Caught in the Middle

Children from divorced homes are caught in the middle of parental conflict significantly more often and are experiencing more resulting stress than children from intact homes. Our intention was to use a brief educational intervention to reduce the number of times divorced parents put their children in the middle. Participants were 45 high school students with divorced parents (male = 22, female = 23; Mage = 15.8). These subjects rated the frequency and stressfulness of 32 such situations. The parents of the intervention group were mailed the subjects' averaged responses on the 32 items and an explanatory letter. The same 32-item questionnaire was given about 1 month after the mailing as the intervention evaluation. Subjects in the intervention group improved more than the two control groups combined, F(1,42) = 3.45, p < .10. These results imply that having divorced parents read some brief information is sufficient to produce behavior changes in the majority of those parents.     

Physiological stress assessment of female workers at kitchen workstation

This paper explores the extent of the physiological stresses of female workers at kitchen workstation while performing the various activities. For this a survey of eighty homemakers and experiment on sixteen respondents having similar physical and physiological parameters was done. Five activities in which the respondents faced maximum problems were selected and were standardized. Physiological stresses including cardiovascular, muscular, and energy expenditure during these activities were then assessed. Study revealed that fatigue during the selected five activities i.e. cutting, grating, rolling, kneading, dish washing, was felt mainly at the wrist, fore arm, followed by discomfort in the shoulders, upper arm, lower back and neck. Energy expenditure for these activities ranged from 7.0 to10 kJ\min, total cardiac cost of work (TCCW) was between 200.81 to 364.30 beats, physiological cost of work (PCW) was 12.82 to 26.26 beats\min; maximum for grating and minimum for rolling. The percent increase in heart rate was maximum for grating 38.56 and minimum for rolling 16.20. Reduction in grip and pinch strength of right hand was found more as compared to the left hand.     

Risk factors and clinical features of text message injuries

Use of mobile phone and sending text message is a very common in today's life. While sending a text message the users need to use their thumb and other palm muscles extensively. The thumb most of the time adducted on the key pad of the mobile and use high force to type the letters. Studies in literature showed that text messaging has an adverse effect on musculoskeletal system of hand. But the extensive study on the type of disorders set in among the users who extensively use mobile phone for texting. This study aims at to evaluate risk factor and clinical feature of the MSD due to hand held devices. Twenty seven subjects participated in this study. Predefined protocols were used to evaluate type of MSD occurred among the subjects. The study revealed that development of tendinitis in extensor pollicis longus, myofascial pain syndrome (70.37%) of adductor pollicis, 1st interossei and extensor digitorum communis . Other associated problems diagnosed were thoracic outlet syndrome (51.85%), fibromyalgia syndrome (25.93%), hypothyroidism (7.41%), wrist tendinitis (14.81%) and De Quervain's syndrome (7.41%). It has been observed that the pathology were tendinitis of extensor pollicis longus, myofascial pain syndrome of thenar muscles and 1st interossei, extensor digitorum communis.     

Participatory ergonomics among female cashiers from a department store

The objective of this paper was to control ergonomic risks among female cashiers working in a department store belonging to the retail market. This study was conducted between May and November 2010. Participatory ergonomics was applied through knowing and understanding how the company works, establishing the work team (Ergo group), training the team in ergonomics-related topics, and making decisions and interventions. The sample was composed of 71 participants--mostly female cashiers--, and all of them have a musculoskeletal compromise, declaring pain or discomfort mainly in the neck, lower back, right wrist and shoulders. Among others, following problems were found: postural overload, repetitive work, manual load handling, mental fatigue, environmental discomfort, variable work schedules, extended working days, and absence of breaks. In the intervention, the main implemented changes were the redesign of workstation, complete change of chairs and keyboards, and the implementation of a rotation system, as well breaks for compensatory exercises. After that, an evident improvement of found problems was observed, therefore it can be concluded that participatory ergonomics is an attractive methodology, appropriate and efficient for solving and controlling ergonomic risks and problems.     

The study of wrist postures of musicians using the WristSystem (Greenleaf Medical System)

This study examined wrist motions of instrumentalists who have never experienced a cumulative traumatic disorder. Eighteen student musicians ranging from 18 to 29 years of age, with more than 9 years of playing experience participated in this study using the WristSystem (Greenleaf Medical System). The wrist motions were measured while participants played their instrument for five minutes. The results indicated a different pattern of wrist movements for each instrumentalist. Pianists demonstrated more ulnar deviation for both hands and more flexion for the left hand than any of the other instrumentalists. The average wrist range of motion for all four movements was under 15 degrees for violinists and violists. The right hand of the cellist had more flexion than any other instrumentalists. For both hands, flutists had more wrist extension than any other instrumentalists. This study provided information about wrist motions of musicians as one of the many factors that contribute to cumulative traumatic disorders. However, further research is needed to identify causal factors, and to promote prevention of the injury.