The main aim of this literature review is to study the role of physical fitness and exercises in prevention as well as rehabilitation of overuse injuries of the upper extremity and neck in workers involved in manual handling tasks. This helps to understand various variables to be considered when developing evidence based exercise program for the prevention or rehabilitation of work related overuse injuries.
Background:
"A manual task may refer to any activity or sequence of activities that involves a person to use their physical body (i.e. the musculoskeletal system) to carry out work" (J.J. Knapik, K. G. Hauret, S. Arnold, M. Canham-Chervak, A. J. Mansfield, E. l. Hoedebecke, D. McMillian, 2010) such as:
Manual handling that involves the application of force to lift, lower, push, pull, carry or otherwise move, hold or restrain any person, animal or thing.
Carrying out repetitive actions.*
Adopting uncomfortable postures or continue in a prolonged postures for a long period of time . *
Using plant, tools or instruments that expose workers to vibration.*
*(Commision for occupational health and safety, 2010)
"An activity is defined as movements or postures adopted at any given time in order to perform a manual task". " Hazards are those that may result in injury or harm to the health of a person". Those manual tasks that potentially cause injury or disease are referred to in this review as hazardous manual tasks. These Include:
(a) Manual tasks involving any of the following characteristics:
"Forces exerted by the worker (e.g. Lifting, lowering or carrying) or on the worker by an item, person or animal (e.g. restraining a dog)" (Commision for occupational health and safety, 2010)
"Awkward postures (e.g. bending forwards, twisting or reaching)" (Commision for occupational health and safety, 2010)
"Sustained postures (e.g. prolonged sitting or standing)" (Commision for occupational health and safety, 2010)
"Repetitive movements (e.g. repeating an action frequently, without breaks" (Commision for occupational health and safety, 2010)
"Vibration - whole-body (e.g. sitting in certain vehicles) and hand-arm (e.g. using certain powered tools)" (Commision for occupational health and safety, 2010)
(b) "Manual tasks involving the handling of a person or an animal". (Commision for occupational health and safety, 2010)
(c) "Manual tasks involving the usage of unstable or unbalanced loads or loads difficult to grasp or hold". (Newzealand, Department Of Labour, 1992; Commision For Occupational Health And Safety, 2010)
Occupational Overuse injuries or repetition strain injuries (RSI) are commonly found in most of the workforces causing pain and distress to the both employers and employees alike. It communally represent a series of conditions depicted by discomfort or persistent pain in muscles, tendons and other soft tissues in the back, neck, shoulder, elbows, wrists, hands or fingers. It describes a large group of ailments experienced due to excessive stress caused by the nature of the person's work or the manner in which they perform it.
Some of the commonly experienced symptoms indicating an overuse injuries condition are described below. (Canberra, University of, 2010) However, any of these conditions should be confirmed by suitable medical practitioner.
Discomfort
Pain
Muscle Fatigue
Swelling
Inflammation
Stiffness
Numbness
Tingling
Burning sensations
Heaviness
Weakness or clumsiness in hands
Headaches
It may affect employees in any occupation, depending on the type of work that is performed and the circumstances under which the work is carried out. Any task which requires rapid repetitive movements, constant postures and or repeated forceful movements is said to place an individual at a higher risk of overuse injuries.
Poor working postures
Poor posture is best addressed by following steps like adjusting the furniture however even good postures should not be maintained indefinitely. Anyone engaged in an activity that involves prolonged postures are advised take regular short breaks/micro breaks, to do some simple stretches or movements that reverse the position they have been maintaining like sitting, stand or bending the back).
Excessive duration and high frequency activities
Breaking up activities or increasing the variety of work can help tired muscles to recover while different muscle groups are being used. Most workers are more mentally stimulated by the increased variety as well.
High forces applied
Applying force to hold, move or restrain an object requires a great deal of muscular effort. The worker should not be required to exert forces which if they find it uncomfortable.
Poor work organization
The worker should be given some level of autonomy over the workflow in order to reduce the risk of injury.
Lack of skills and experience
Training and educating the employee can help prevent injuries.
Other personal or individual factors
If a person is away from work for a long period of time, they should be allowed a period of adjustment to return to previous working rates. The adjustment period will depend on the individual and on the length of their absence. (Canberra, University of, 2010)
Method
Search strategies:
A literature search was carried out in the various electronic databases like Medline, PubMed, CINAHL, Sport-discuss, Mantis and Springer for full text versions from 1990 to present. A Boolean search of the terms such as "overuse injuries, manual handling, exercises , work injures, upper extremity disorders , rehabilitation of injured worker, musculoskeletal injury risk factors, systematic review, physical strength, biomechanical applications , job analysis" revealed, 30 papers.
Selection of inclusion/ exclusion criteria for literature:
After setting a criterion, the title, keywords, and abstract of the papers were assessed to meet the inclusion criteria regarding design, subjects, and exercise intervention. Full articles of peer reviewed English language journals from the last decade with any possible relevance were retrieved for final assessment and 13 papers were eventually selected using a standardized form. The literature was collated and sorted according to the names of the authors in alphabetical order and relevance. Cross referencing of the reference list of the selected papers was also done to check for any reference paper that met our criteria.
Data extraction:
Two authors independently extracted data, type of study and its outcome measures and results. The individual extracted results were then compared and the common data extracted was included in the study.
Data Analysis:
The pooled data was then categorized and tabulated for further study.
Results
In total about 30 papers were identified on a general search out of which 12 papers were shortlisted based on the inclusion and exclusion criteria.
S. No.
Author and Yea r
Title
Type of study/ Method
Findings
1
A. G. Williams, M. P. Rayson and D. A. Jones
2002
Resistance training and the enhancement of the gains in material-handling ability and physical fitness of British Army recruits during basic training
Forty-three males of mean 19.2 years of age, 1764mm in height, mass of 73.0kg and nine females 19.1years, 1641mm, 62.0kg on average participated in a modified basic training. Testing was done in the week before and in the final week of the 11 week basic training.
Improvements observed for all six material-handling tests, including 12% for maximal box lifting, 19% for repetitive lifting and carrying and 17% for loaded marching, and other established measures of aerobic fitness, strength and kinanthropometric characteristics. This report demonstrates the progress in material-handling ability as well as other aspects of physical fitness which were noticed in recruits of British Army basic training. According to this report the physical fitness can be enhanced using a physical training programme consisting of a carefully designed resistance training element. The most important observation of the paper includes the improvements shown in performance on material-handling tasks requiring muscular strength, representing many of the tasks the soldiers encounter in their line of work.
2
Alun C. Williams and Mick Wilkinson
2007
Simple anthropometric and physical
Performance tests to predict maximal
Box-lifting ability
In this study 2 groups of adults were taken. Group 1 was asked to perform maximum lifts to 1.4 m and group 2 was asked to perform maximum lifts of 1.7 m respectively. All the participants were asked to do 1 RM for upright row, strength, body mass, body composition and height.
According to the initial study on maximal box-lift performance of 1.4 m, 42 ± 12 kg was calculated from a equation including the variation in body mass, body composition, and upright row IRM. It was noted that there was a variation of 95% in 1.4-m box- lifting performance. On the other hand the second study, showed only 80% of the variation in 1.7-m box-lifting performance which was 51 ± 15 kg using the best predictor equation. Upright row IRM strength proved to be useful tool to predict of box-lifting ability to approximately chest height for most adults. This may be because of similarity in the muscle group used and the type of muscle action
3
Christina Ahlgren, Kerstin Waling, Fawzi Kadi, Mats DjupsjoÈ backa, Lars-Eric Thornell and Gunnevi Sundelin
2001
Effects on physical performance and pain from three dynamic training programs for women with work-related trapezius myalgia.
Women with neck/shoulder pain participated in the study. The women included were less than 45 years of age and suffered from pain in the neck and shoulder muscles for more than one year and were fully employed. The subjects had to consider their work as contributing to the condition, and the intensity of the pain the subject's experienced caused difficulty in performing their work for least once a week. When the subjects are entering the study should not be on sick leave, neither could they have been on sick leave for one month or during the year before the study.
Signs such as a reduced range of motion in the neck: lateral flexion and/or rotation and single /multiple points of tenderness in the neck/shoulder muscles at palpation were require in clinical examination.
Ten subjects with orthopaedic, neurological, rheumatological and/ or metabolic diseases were excluded from the study. The remaining 126 subjects were randomly distributed into three training and one non-training group. To make it possible for a working A semi-randomization was performed according to convenience of the participants. Training hours were allotted and the participants were able to choose hours suiting their own work schedules. The content of the four programs was explained to them. Twenty-four subjects were unable to finish their training because of personal problems like persistent colds or pregnancy etc. Altogether 102 subjects completed their training programs.
There was no change in the anthropometric data and other background variables between the groups with the exception of the co-ordination training group which was exposure higher exercise intensities. The subjects who completed the intervention did not differ significantly to the dropouts with reference to anthropometric data or duration of pain, but were lower for the category which was active all day.
It was observed from this report that women with trapezius myalgia improved their physical performance with training and found the pain to subside considerably after 10 weeks of strength-training, endurance-training, or co-ordination training for neck/shoulder muscles, in comparison to the non-training group. In general the type of training did not any effect on decrease in perceived pain. It was observed that strength training was more efficient in lowering the pain. This can be seen by a significant difference in the ratings of worst possible pain for the strength on contrary the other groups on comparison between the groups.
Both strength and aerobic fitness training were described earlier to reduce pain in subjects with neck/ shoulder pain. This study similar to other studies comparing multiple types of training failed to find dissimilarity between different types of training on their consequence pain in neck/shoulder pain. This could be attributed to the findings that the reduction in perceived pain only to a minor degree could be explained by physical improvements.
4
Daniel Bartlett, Kang Li, and Xudong Zhang
2007
A relation between dynamic strength and manual materials-handling strategy affected by knowledge of strength.
Thirty-two candidates (16 men and 16 women) were initialy tested for their isokinetic strengths for trunk extension, knee extension, shoulder extension, and shoulder abduction. This group was then divided into two groups. The knowledge feedbacks of their strength testing results were given to one but feedback not provided to the other group. The Participants later performed the same load handling task; this involved carrying batches of various weight plates while allowed to assort batches of more than one plate into any sequence.
The total isokinetic strength score and knowledge feedback both represented dynamic strength, and showed a considerable outcome on measures quantifying the batch-assorting strategy.
5
Gamze Senbursa; Gul Baltacı ; Ahmet Atay
2006
Comparison of conservative treatment with and without manual
physical therapy for patients with shoulder impingement
syndrome: a prospective, randomized clinical trial
This study was conducted to compare the efficiency of 2 physical therapy treatment procedures for shoulder impingement syndrome. This was done by using either self training program or joint and soft tissue mobilization techniques. In this study 2 groups of patients were taken. Each group was divided with equal no: of patients i.e. n= 15.They were already diagnosed with an outlet impingement syndrome of the shoulder. Group1 was treated by strengthening the depressors of the humeral head along with a self guided self training program, whereas group 2 was treated by joint and soft tissue mobilization techniques. Group 1 was instructed to perform home program for 7days/week for 10-15 minutes. Group 1 program includes stretching, strengthening exercises, active range of motion (ROM) exercises as well as rotator cuff, rhomboids, levator scapulae and serratus anterior exercises with thera bands. On the other hand group 2 was given a prescribed program for 12 sessions. They were instructed to perform for 3 days/week in a clinic. Their program includes soft tissue mobilization techniques, stretching, strengthening exercise program, ice application and patient education in clinic. Later on after the initiation of treatment after 3 months both groups were tested for pain level with visual analogue scale (VAS), tested for range of motion with goniometry, algometry for the pain threshold and functional assessment was done with the help of functional assessment questionnaire. (Neer Questionnaire)
From the report it is observed that subjects in both groups reported a significant reduction in pain and also an increase in the functions of shoulder. However, manual therapy group showed promising results as compared to exercise group.
For e.g. : In manual therapy group pain was decreased from(±SD) of 6.7 to (±0.3) after comparing it before and after the treatment. In this group in mean 2.0 (±2.0) is seen after the treatment. On comparison with the exercise group, it was seen that pain in this group was decreased from a pre-treatment mean of 6.6 (±1.4) to a post-treatment mean of 3.0 (±1.8).
On comparison of range of movement it was noticed that in manual therapy group flexion, abduction and external rotation was significantly improved but there was no improvement in range of motion was found in other group.
On functional assessment it was seen that there were statistically differences between the groups in function (P>0.05).
There was a significantly greater improvement seen in the group 2 in the Shoulder satisfaction Score and Neer Questionnaire score than group 1.
6
Jean-Louis Croisier, Marguerite Foidart-Dessalle, France Tinant, Jean-Michel Crielaard, Be´ne´dicte Forthomme
2007
An isokinetic eccentric programme for the management of chronic lateral epicondylar tendinopathy.
Ninety-two patients showing symptoms of unilateral chronic lateral epicondylar tendinopathy for 8months (mean) were placed in a control group or into an eccentrically trained group.
A standardised passive rehabilitation programme that excluded strengthening exercises was administered to the control group. The trained group performed, eccentric exercises based on the repetitive lengthening of the active musculo-tendinous units along with the passive program. The trained group started exercises with sub maximal contraction intensity and at slow movement speed.
The eccentrically trained group showed better results in comparison to the non-strengthening control group. There was a significant drop intensity of pain, after a month's treatment along with an absence of strength deficit on the involved side, when forearm supinator and wrist extensor muscles when both sides of the eccentrically trained group were compared. The tendon image showed improvement, indicated by a reduced thickness and a homogenous tendon structure. There was a remarkable development of disability in occupational, spare time and sports activities.
7
Jeffrey A. Fleming, Amee L. Seitz, and D. David Ebaugh
2010
Exercise Protocol for the treatment of rotator cuff impingement syndrome.
Studies were obtained from various electronic databases using the search terms shoulder, impingement, rotator cuff, rehabilitation, physical therapy, Physiotherapy, and exercise. Searches were also performed in the references of the identified studies. Studies were selected with inclusion and exclusion criteria and reviewed.
There was significant evidence in randomized clinical trials that exercise can be used as effectively for treating individuals with RCIS. However the study showed that the exercise program should be individualised to gain maximum benefit
8
Kraemer, W. J., S. A. Mazzetti, B. C. Nindl, L. A. Gotshalk, J. S. Volek, J. A. Bush, J. O. Marx, K. Dohi, A. L.
Go´ Mez, M. Miles, S. J. Fleck, R. U. Newton, and K. Ha¨ Kkinen
2001
Effect of resistance training on women's strength/power and occupational performances
In this study untrained women aged between 23-27 years were selected. They were randomly placed in different groups. They were given (TP,N=17 and TH, N=18 or upper body resistance training (UP,N=18 and UH,N=15)provided to perform total body and upper body resistance training program and field (FLD,N=14, aerobic training program groups (AER, N= 11), Field (FLD, N=14). Two periodized resistance training programs were given along with aerobic training. They were asked to use 3-8 RM training loads to execute explosive exercise movements. On the other group was asked to do slower movements with 8-12 RM. The field group performed partner exercises and plyometrics. After 3 and 6 months of training participants were tested for body composition, strength, endurance, power, 2- mile loaded run, power, maximal and repetitive box lift and U.S Army Physical Fitness Tests.
This study showed that over the 6 months period strength training improved physical performances of women and adaptations in power ,endurance and strength and which was specific to the slight differences like exercise choice and speeds of movement in the resistance training program ( strength/ hypertrophy versus strength/ power. The tasks which involved upper body musculature, in that tasks upper and total body resistance training resulted in same improvements. After resistance training program physical performance measures were reduced in women which underscore the importance of such training for physically demanding occupations.
Physical performances of women improved over 6 months of strength training with adaptations in strength, power, and endurance were specific to the delicate differences (e.g., exercise choice and speeds of exercise movement) in the resistance training programs (strength/power vs strength/hypertrophy). Upper- and total-body resistance training resulted in similar improvements in occupational task performances, especially in tasks that involved upper-body musculature. Gender differences in physical performance measures were reduced after resistance training in women, which underscores the importance of such training for physically demanding occupations
9
Marjon D van Eijsden-Besseling, J Bart Staal , Antonius van Attekum, Rob A de Bie
and Wim JA van den Heuvel
2008
No difference between postural exercises and strength
and fitness exercises for early, non-specific, work-related
upper limb disorders in visual display unit workers:
a randomised trial
Eighty-eight visual display unit workers in the initial stages of nonspecific work-related upper limb disorders where selected for the purpose of the study. This group was divided into two in which the first group received 10 weeks of postural exercises while the second received 10 weeks of strength and fitness exercises.
A 10-cm visual analogue scale was used to measure the pain, disability was measured with a Disabilities of Arm, Shoulder and Hand questionnaire, and Short Form-36 was used to measure health-related quality of life. Complaints of the participants who suffering upper limb pain was also collected. Outcome of the study was collected at baseline and again at 3, 6, and 12 months.
There was no significant difference between the groups at 3 months, 6 months, or at 12 months when comparing pain reduction. Differences between the groups with upper limb complaints, disability, and health related
quality of life were also small and not significant at any measurement.
Better outcomes where not obtained with postural exercises than strength and fitness exercises. However, 55% of visual display unit workers with early non-specific work-related upper limb disorders reported relief, one year after both interventions were started.
10
Mats Hagberg, Karin Harms-Ringdahl, Ralph Nisell, Ewa Wigaeus Hjelm
2008
Rehabilitation of neck-shoulder pain in women industrial workers: A randomized trial comparing isometric shoulder endurance training with isometric shoulder strength training
A randomized trial was conducted in three occupational health care centers. Women industrial workers with nonspecific neck-shoulder pain diagnosed with the diagnosed "cervicobrachial syndrome" complying with The International Classification of Diseases, 10th revision were selected. Thirty-eight patients finished the isometric shoulder endurance training and 31 patients completed the isometric shoulder strength training over a period of twelve weeks.
Isometric strength training for the shoulder resulted in a decrease in RPE by nearly one unit at work and a 5% to 15% increase in arm motion performance compared with the endurance training. The isometric shoulder strength training more effectively improved strength of left side shoulder abduction, but no major variations were observed for the other strength outcomes. The isometric shoulder endurance training was not as successful compared to the strength training in the endurance test
Physical training programs for neck-shoulder pain may contain isometric shoulder muscular strength exercise in conjunction to isometric shoulder endurance training, rather than endurance training only.
Isometric shoulder strength training was observed to marginally better than isometric endurance training for decreasing RPE at work and an improvement in arm motion performance. Isometric shoulder strength training was more effective in improving strength as anticipated, but the differences between the two types of training were insignificant. Isometric endurance training was not more successful than strength training in improving RPE during the endurance test. In cervicobrachial syndrome, inclusion of strength training may be more advantageous than only endurance training when considering a physical training program.
11
Vicki S. Conn, Adam R. Hafdahl, Pamela S. Cooper, Lori M. Brown, Sally L. Lusk
2009
Meta-analysis of workplace Physical activity Interventions
An comprehensive search located published and unpublished intervention papers reported from 1969 to 2007. Results were coded from primary studies. Random-effects meta-analytic methods, including moderator examination, were completed by 2008.
Effects on most variables were significantly varied because dissimilar in studies that were included. Standardized mean difference (d) effect sizes were made across almost 38,231 subjects.
An appreciable positive effects were noted for physical activity behaviour; fitness; lipids; anthropometric measures, work attendance and job stress.
The outcomes of this study suggest that physical activity programs are effective beyond direct benefits on health. Even simple reductions in absence from work may result in substantial financial savings when compounded by the number employees involved. The findings concerning health expenses should be interpreted carefully given the very small sample size and the inadequate time between interventions and utilization measurement between these studies. Some programs may have performed health screening before encouraging subjects to begin exercising, which might have prompted needed health care. Long-term follow-up studies could determine the long-term economic impact of these programs
12
; Malmivaara A; Uitti J; Rinne M; Palmroos P; Laippala P
2003
Effectiveness of dynamic muscle training, relaxation training, or ordinary activity for chronic neck pain: randomised controlled trial.
In this study 393 female office workers were selected with mean age of 45 years. They were suffered from chronic non specific neck pain. They were randomly assigned to relaxation training (n=128) and dynamic muscle (n=135) training for 12 weeks. After 6 months of baseline they were also given 1 week of reinforcement training.
No significant difference in the decrease of neck was reported by the groups during the follow up. However, the range of motion for cervical rotation and lateral flexion was found to be higher in the training groups than in the control group.
Dynamic muscle training and relaxation training did not show any promising improvement in neck pain when compared with ordinary activity.
Discussion
From the data collected, it was observed that exercise showed significant improvement of conditions in work related injuries. However, according to Eijsden-Besseling et.al the variability between different types of exercises is not very drastic. According to Senbursa et.al; exercise alone did not show a significant improvement in the condition but combined along with adjunct therapies (example manual therapy) revealed better improvement. According to Williams and Wilkinson, there is a strong connection between exercise test like 1 RM and functional test like box lift and hence can be used as a vital tool in pre placement screening and designing prevention exercises for overuse injuries.
Strength training has also shown to improve strength power and endurance (Kraemer et.al. 2010) and thus increase the work tolerance and improvement in occupational task performance. Different types of exercises like isometrics and endurance training displayed better outcomes than endurance training alone for neck and shoulder pain. The same study also indicated that strength training reduced the rate of RPE in endurance training. Isokinetic eccentric strength training has been shown to be a vital tool in the treatment of chronic lateral epicondyl tendinopathy (CROISIER, Jean-Louis et al., 2007). According to Anderson et al. improved outcomes were obtained in neck and shoulder injuries for those people who underwent supervised exercise training than the people who underwent passive treatment options. This is an important feature as it amplifies the potential or requirement of exercise in the rehabilitation phase following injury.
However Conn et.al believe that other than direct health benefits, exercise showed reduction in absenteeism that otherwise would cause financial loss to the company. Therefore exercise has an economic effect on a company rather than just the prevention point of injury. Exercise however should be individualized for maximum benefit as there are significant interpersonal differences in manifestation of injury and hence can help in creating an individual specific treatment program in individuals.
Knowledge of strength also is an important factor in determining work strategy in manual handling as strategies can be tailored according to the individual capabilities.
Conclusion
The data acquired from the reviewed literature suggests that the benefits of exercise in the management of occupational injuries demonstrate a great potential. Nevertheless exercise alone is not the best mode of treatment and should be used in conjunction with other forms of rehabilitation for the best outcome. The difference between various forms of exercise is minimal and should be prescribed after a detailed assessment of the individuals' needs and goals. The training should be work specific and focus on the prevention of the recurrence of the injury. An ergonomic change to the surrounding also plays a vital tool in prevention of overuse injuries. Pre-placement screening also has a critical role in the prevention of injuries as potential risk factors and behaviours and can be identified and addressed before it turns into a serious injury. An injury in the work place causes tremendous psychological and financial strain on the individual and the company alike.
