healthcare Article
Musculoskeletal Disorders and Working Posture among Dental and Oral Health Students Andrew Ng, Melanie J. Hayes * and Anu Polster Melbourne Dental School, The University of Melbourne, 720 Swanston Street, Melbourne 3010 VIC, Australia; [email protected] (A.N.); [email protected] (A.P.) * Correspondence: [email protected]; Tel.: +61-3-9341-1535; Fax: +61-3-9341-1595 Academic Editors: Peter A. Leggat and Derek R. Smith Received: 30 November 2015; Accepted: 20 January 2016; Published: 23 January 2016
Abstract: The prevalence of musculoskeletal disorders (MSD) in the dental professions has been well established, and can have detrimental effects on the industry, including lower productivity and early retirement. There is increasing evidence that these problems commence during undergraduate training; however, there are still very few studies that investigate the prevalence of MSD or postural risk in these student groups. Thus, the aim of this study was to determine the prevalence of MSD and conduct postural assessments of students studying oral health and dentistry. A previously validated self-reporting questionnaire measuring MSD prevalence, derived from the Standardised Nordic Questionnaire, was distributed to students. Posture assessments were also conducted using a validated Posture Assessment Instrument. MSD was highly prevalent in all student groups, with 85% reporting MSD in at least one body region. The neck and lower back were the most commonly reported. The final year dental students had the highest percentage with poor posture (68%), while the majority of students from other cohorts had acceptable posture. This study supports the increasing evidence that MSD could be developing in students, before the beginning of a professional career. The prevalence of poor posture further highlights the need to place further emphasis on ergonomic education. Keywords: musculoskeletal disorders; dental; students; risk
1. Introduction Musculoskeletal disorders (MSD) are defined as muscular pain or injuries to the human support system that can occur after a single event or cumulative trauma, negatively impacting daily activities [1]. MSD can range from pain in the upper limbs, such as the forearm and wrist, to postural muscles such as the upper and lower back, neck and shoulders as well as lower extremities such as hips, thighs, knees and ankles. Left untreated, MSD can evolve into more severe degenerative and inflammatory conditions [1]. Of all work-related complaints, MSD may be the most ubiquitous symptom in the modern workforce. A study in 2011 revealed that MSDs were the most frequent health complaint by European, United States and Asian Pacific workers [2]. MSD is common in occupations that involve repetitive movements and prolonged, static postures such as sitting or standing, both of which are prerequisites to dental clinicians [3–6]. Studies have indicated that MSDs are multifactorial and are not just limited to physical causes. Psychosocial factors such as stress have also been discovered to be significant contributors in developing MSD [7]. Prolonged static postures (PSP) are inherent in dentistry work. Awkward postures that involve forward bending and repeated rotation of the head, neck and trunk to one side are common occurrences during clinical work. As posture deviates more from neutral, the muscles that are responsible for the
Healthcare 2016, 4, 13; doi:10.3390/healthcare4010013
www.mdpi.com/journal/healthcare
Healthcare 2016, 4, 13
2 of 15
preferred side of rotating or bending become stronger and the matching antagonistic muscles become elongated and weakened, creating a muscle imbalance [8]. Muscles that are under stress from PSP are also susceptible to ischemia, due to the prolonged contraction and following fatigue [9]. Under normal conditions, damaged tissues under these conditions are repaired during periods of rest. However, in dentistry the rate of damage exceeds the rate of repair due to insufficient rest periods, potentially leading to necrosis of the muscle. The body, in an effort to protect the stressed area from further pain or injury, compensates by using another part of the muscle to maintain posture. This is known as muscle substitution [8]. This is a self-perpetuating cycle, where tighter muscles become tighter and the weaker muscles become weaker, and can result in the development of a whole range of MSDs. It has been well established in previous studies that there is a strong association between MSD and the clinical burdens of dental practitioners [10–13]. A previous review in this area discovered that 64%–93% of dental professionals suffer from general work-related MSD [10], representing a significant proportion of the workforce. This can have overall detrimental effects on the industry’s work force, resulting in lower productivity, increased sick leave and early retirement from the profession [1]. There is also some evidence to suggest that MSD can develop in students during their education and training [14–18]. This may be attributed to the pressures of tertiary study and the physical burden of clinical training. With increasing numbers of students, and therefore professionals, in the dental health industry, it is crucial to determine the prevalence and address the aetiology of MSD involved with this profession. Despite a widespread awareness of this occupational health burden, a recent literature review found that dental professionals continue to suffer from MSD at alarming rates [13]. Research suggests that symptoms may arise during the education and training of students [14,15]. Students are taught and are aware of the risks of MSD during the early phase of their training, but over time, less emphasis is given to this occupational health issue [16]. Research in this area has improved in recent years; however, there have only been a limited number of studies in Australia [19]. Studies also focus more on professionals in the industry rather than students. Dental and oral health students are a useful group to research as it is logical to hypothesise that symptoms may potentially arise during this educational phase of dental professionals. With an ever-increasing student population and, subsequently, registered professionals in the field of oral health and dentistry in Australia, research would be crucial in understanding potential occupational health problems as well as providing support for further research into MSD in the related dental professions. Thus, the aim of this study was to determine the prevalence of musculoskeletal pain and postural deficits in dental and oral health students and to investigate any risk factors that may influence the rate of MSD in this population. This will be achieved by: a. b.
Measuring MSD prevalence using a self-administered questionnaire Posture assessment
2. Methods This study was carried out as descriptive and exploratory research, using a cross-sectional approach. The study examines the prevalence of MSD in students studying the Bachelor of Oral Health (BOH) and Doctor of Dental Surgery (DDS) degrees at the University of Melbourne, Australia. The study duration of the BOH and DDS, respectively, are three and four years to completion. In addition to assessing the prevalence of MSD, the study also conducted an assessment of posture as an influencing factor of MSDs. A cross-sectional design was selected as this was identified as the most appropriate method to answer the research question. Cross-sectional studies measure exposures and outcomes at a single point in time, and, as such, are useful for yielding prevalence estimates. This study design is efficient in terms of cost and time, as it allows several factors to be studied; given that this project is required to be completed in less than 12 months, a cross-sectional approach was considered the most appropriate choice. Ethics approval was obtained from the University of Melbourne in August 2015.
Healthcare 2016, 4, 13
3 of 15
The questionnaire was two pages long and included a plain-language statement explaining the Healthcare 2016, 4, 13 3 of 14 study; consent was implied by completing the questionnaire. The questionnaire was an adapted version of an original tool by Smith and Leggat [20] that has been previously used among medical, version of an original tool by Smith and Leggat [20] that has been previously used among medical, Healthcare 2016, 4, 13 3 of 14 dental, nursing and occupational therapy students, as well as dental hygienists and dentists [10,21], dental, nursing and occupational therapy students, as well as dental hygienists and dentists [10,21], andand takes less than five minutes to complete. takes less than five minutes to complete. version of an original tool by Smith and Leggat [20] that has been previously used among medical, Students were invited to participate a postural assessment, were given a consent Students were alsoalso invited to participate in ain postural assessment, andand were given a consent dental, nursing and occupational therapy students, as well as dental hygienists and dentists [10,21], Healthcare 2016, 4, 13 3 of 14 form to complete and return should they wish to participate. The postural assessment used was the form to complete and return should they wish to participate. The postural assessment used was and takes less than five minutes to complete. the Branson’s Dental Operator Posture Assessment Instrument (Table 1) [22], and was conducted during Branson’s Dental Operator Posture Assessment (Table 1) [22], and wasgiven conducted Students were also invited to participate in Instrument a postural assessment, and were a consent version of an original tool by Smith and Leggat [20] that has been previously used among medical, a timetabled clinical or pre‐clinical scaling session, with assessment done by the student researcher. during a timetabled clinical or pre-clinical scaling session, with assessment done by the student form to complete and return should they wish to participate. The postural assessment used was the dental, nursing and occupational therapy students, as well as dental hygienists and dentists [10,21], Scores ranged from 10 to 194, with the lowest score being the most ideal. From the scores, participants’ researcher. Scores ranged from 10 to 194, with the lowest score being the most ideal. From the scores, Branson’s Dental Operator Posture Assessment Instrument (Table 1) [22], and was conducted during and takes less than five minutes to complete. postures postures were categorised as Acceptable, Compromised or Harmful. These categories can participants’ were categorised Acceptable, or Harmful. These can be a timetabled clinical or pre‐clinical scaling session, with assessment done by the student researcher. Students were also invited to as participate in Compromised a postural assessment, and were categories given a consent interpreted as follows: be interpreted as follows: Scores ranged from 10 to 194, with the lowest score being the most ideal. From the scores, participants’ form to complete and return should they wish to participate. The postural assessment used was the
postures were (10–40): categorised as in Acceptable, Compromised or operator Harmful. These categories can be Branson’s Dental Operator Posture Assessment Instrument (Table 1) [22], and was conducted during Acceptable Acceptable (10–40): Postures in this category will not put the operator at risk for musculoskeletal Postures this category will not put the at risk for musculoskeletal interpreted as follows: a timetabled clinical or pre‐clinical scaling session, with assessment done by the student researcher. discomfort or cumulative trauma disorders. ➢ discomfort or cumulative trauma disorders. Scores ranged from 10 to 194, with the lowest score being the most ideal. From the scores, participants’ Compromised (41–80): Postures in this category, if held for more than five minutes repeatedly Compromised Acceptable (10–40): Postures in this category will not put the operator at risk for musculoskeletal (41–80): Postures in this category, if held for more than five minutes repeatedly postures were categorised as put Acceptable, Compromised or Harmful. These categories can be throughout the work day, will the operator risk for musculoskeletal or discomfort or cumulative trauma disorders. ➢ throughout the work day, will theput operator at risk for at musculoskeletal discomfort or discomfort cumulative interpreted as follows: cumulative trauma disorders. trauma Compromised (41–80): Postures in this category, if held for more than five minutes repeatedly disorders. Harmful (81–194): Posture in this category, if held for any length of time, will put the operator throughout the work day, will category, put the ifoperator at risk for of musculoskeletal discomfort Harmful Acceptable (10–40): Postures in this category will not put the operator at risk for musculoskeletal (81–194): Posture in this held for any length time, will put the operator or at risk for cumulative trauma disorders or injury. discomfort or cumulative trauma disorders. ➢ atcumulative trauma disorders. risk for cumulative trauma disorders or injury. Harmful (81–194): Posture in this category, if held for any length of time, will put the operator Compromised (41–80): Postures in this category, if held for more than five minutes repeatedly Table 1. Branson’s Dental Operator Posture Assessment Instrument (PAI). at risk for cumulative trauma disorders or injury. throughout the work day, will Operator put the Posture operator at risk Instrument for musculoskeletal discomfort or Table 1. Branson’s Dental Assessment (PAI). Acceptable Compromised Harmful 1 min 3 min 5 min Total cumulative trauma disorders. Table 1. Branson’s Dental Operator Posture Assessment Instrument (PAI). HIPS Acceptable Compromised Harmful 1 min 3 min 5 min Total Harmful (81–194): Posture in this category, if held for any length of time, will put the operator Level on stool Hips not level on stool HIPS Acceptable Compromised Harmful 1 min 3 min 5 min Total at risk for cumulative trauma disorders or injury. (1 POINT) (2 POINTS) HIPS Level on stool Hips not level on stool TRUNK (1 POINT) (2 POINTS) Level on stool Hips not level on stool Table 1. Branson’s Dental Operator Posture Assessment Instrument (PAI). Front to back ≤20° Front to back >20°, 20°, 20˝ , 20°, 20˝ , 20°, 20°, 20°, 20˝ , 20°, 20°, 20°, 20°, 20 , 20°, 20°, 20 , 20°, 20°, 20°, 20˝ , 20°, 20°, 20°, 2 Days Affected daily life Needed treatment
33.3 50 0 0
68.8 36.4 18.2 0 Shoulders
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
50 44.4 44.4 22.2
31.3 60 20 0 Upper Back
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
38.9 28.6 28.6 42.9
50 62.5 50 12.5 Elbows
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
0 0 0 0
5.6 0 0 0 Forearms
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
5.6 0 0 0
12.5 50 50 50 Wrists/Hands
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
44.4 25 25 0
50 25 25 12.5
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Table 5. Prevalence of MSD by lower body region. Reported MSD (% Students) Cohort
BOH1
BOH3
DDS1
DDS4
44.7 50 29.4 5.9
64 62.5 25 18.8
6.6 60 60 40
3.8 0 0 0
14.5 63.6 45.5 18.2
7.7 100 0 0
3.9 33.3 33.3 0
11.5 33.3 0 0
6.25 100 0 0
15.4 100 25 25
Lower Back Any symptoms Persisted > 2 Days Affected daily life Needed treatment
33.3 66.7 66.7 33.3
62.5 50 30 20 Hips/Thighs
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
0 0 0 0
18.8 100 66.7 33.3 Knees
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
11.1 50 50 50
6.25 100 100 100 Calves/Lower Leg
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
5.6 0 0 0
0 0 0 0 Ankles/Feet
Any symptoms Persisted > 2 Days Affected daily life Healthcare 2016, 4, 13 Needed treatment
5.6 100 100 0
5.3 75 25 0
7 of 14
MSD Prevalence between Cohorts 80
*
No. of Students (%)
70 60 50 40
*
30 20 10 0 Neck
Shoulder
Upper Back
Wrist/Hands
Lower Back
Body region BOH1
BOH3
DDS1
DDS4
Figure 1. MSD prevalence of body regions between the cohorts studied. * p-value < 0.05. Figure 1. MSD prevalence of body regions between the cohorts studied. * p-value < 0.05.
Statistical Statistical correlates correlates of of MSD MSD were were differentiated differentiated into into two two tables, tables, with with the the predictors predictors shown shown in in Table 6 and the protective factors shown in Table 7. Table 6 and the protective factors shown in Table 7. Table 6. Statistical correlates and predictors of MSD. Body Region
Predictor Female DDS course
OR * 1.98 1.83
(95% CI) 0.98–3.99 1.22–2.75
SEM 0.71 0.38
p-Value 0.05 0.003
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Table 6. Statistical correlates and predictors of MSD. Body Region
Predictor
OR *
(95% CI)
SEM
p-Value
Neck
Female DDS course DDS1 cohort BOH3 cohort No Loupes Computer type (Laptop) No previous practitioner experience Usage environment (Desk) Low preclinical hrs/week
1.98 1.83 4.08 4.4 1.52 1.64 1.54 1.73 1.88
0.98–3.99 1.22–2.75 1.37–12.14 1.04–18.59 1.03–2.25 1.14–2.35 1.04–2.28 1.07–2.80 1.16–3.05
0.71 0.38 2.27 3.24 0.3 0.3 0.31 0.43 0.47
0.05 0.003 0.012 0.044 0.034 0.008 0.032 0.026 0.011
Low clinical hrs/week Female Usage environment (Table) Stress (high) High clinic hrs/week
1.7 2.27 1.35 5.19 2.29
1.08–2.67 1.12–4.61 1.02–1.79 1.86–14.54 1.13–4.62
0.39 0.82 0.19 2.73 0.82
0.021 0.022 0.038 0.002 0.021
Shoulder Upper Back Wrists/Hands Lower Back
Note: *Odds ratio.
Table 7. Statistical correlates and predictors for non-reporting of MSD. Body Region
Predictor
OR *
(95% CI)
SEM
p-Value
Shoulder
Male Low computer usage (hrs/week)
0.49 0.37
0.28–0.84 0.15–0.88
0.14 0.16
0.01 0.024
Upper Back
DDS course Male Low alcohol consumption No previous practitioner experience Low clinical hrs/week No Loupes Usage environment (Desk)
0.52 0.53 0.52 0.58 0.5 0.58 0.43
0.35–0.79 0.31–0.90 0.35–0.79 0.39–0.86 0.32–0.79 0.39–0.86 0.27–0.68
0.11 0.15 0.11 0.12 0.12 0.12 0.1
0.002 0.02 0.002 0.007 0.003 0.007
Musculoskeletal Disorders and Working Posture among Dental and Oral Health Students Andrew Ng, Melanie J. Hayes * and Anu Polster Melbourne Dental School, The University of Melbourne, 720 Swanston Street, Melbourne 3010 VIC, Australia; [email protected] (A.N.); [email protected] (A.P.) * Correspondence: [email protected]; Tel.: +61-3-9341-1535; Fax: +61-3-9341-1595 Academic Editors: Peter A. Leggat and Derek R. Smith Received: 30 November 2015; Accepted: 20 January 2016; Published: 23 January 2016
Abstract: The prevalence of musculoskeletal disorders (MSD) in the dental professions has been well established, and can have detrimental effects on the industry, including lower productivity and early retirement. There is increasing evidence that these problems commence during undergraduate training; however, there are still very few studies that investigate the prevalence of MSD or postural risk in these student groups. Thus, the aim of this study was to determine the prevalence of MSD and conduct postural assessments of students studying oral health and dentistry. A previously validated self-reporting questionnaire measuring MSD prevalence, derived from the Standardised Nordic Questionnaire, was distributed to students. Posture assessments were also conducted using a validated Posture Assessment Instrument. MSD was highly prevalent in all student groups, with 85% reporting MSD in at least one body region. The neck and lower back were the most commonly reported. The final year dental students had the highest percentage with poor posture (68%), while the majority of students from other cohorts had acceptable posture. This study supports the increasing evidence that MSD could be developing in students, before the beginning of a professional career. The prevalence of poor posture further highlights the need to place further emphasis on ergonomic education. Keywords: musculoskeletal disorders; dental; students; risk
1. Introduction Musculoskeletal disorders (MSD) are defined as muscular pain or injuries to the human support system that can occur after a single event or cumulative trauma, negatively impacting daily activities [1]. MSD can range from pain in the upper limbs, such as the forearm and wrist, to postural muscles such as the upper and lower back, neck and shoulders as well as lower extremities such as hips, thighs, knees and ankles. Left untreated, MSD can evolve into more severe degenerative and inflammatory conditions [1]. Of all work-related complaints, MSD may be the most ubiquitous symptom in the modern workforce. A study in 2011 revealed that MSDs were the most frequent health complaint by European, United States and Asian Pacific workers [2]. MSD is common in occupations that involve repetitive movements and prolonged, static postures such as sitting or standing, both of which are prerequisites to dental clinicians [3–6]. Studies have indicated that MSDs are multifactorial and are not just limited to physical causes. Psychosocial factors such as stress have also been discovered to be significant contributors in developing MSD [7]. Prolonged static postures (PSP) are inherent in dentistry work. Awkward postures that involve forward bending and repeated rotation of the head, neck and trunk to one side are common occurrences during clinical work. As posture deviates more from neutral, the muscles that are responsible for the
Healthcare 2016, 4, 13; doi:10.3390/healthcare4010013
www.mdpi.com/journal/healthcare
Healthcare 2016, 4, 13
2 of 15
preferred side of rotating or bending become stronger and the matching antagonistic muscles become elongated and weakened, creating a muscle imbalance [8]. Muscles that are under stress from PSP are also susceptible to ischemia, due to the prolonged contraction and following fatigue [9]. Under normal conditions, damaged tissues under these conditions are repaired during periods of rest. However, in dentistry the rate of damage exceeds the rate of repair due to insufficient rest periods, potentially leading to necrosis of the muscle. The body, in an effort to protect the stressed area from further pain or injury, compensates by using another part of the muscle to maintain posture. This is known as muscle substitution [8]. This is a self-perpetuating cycle, where tighter muscles become tighter and the weaker muscles become weaker, and can result in the development of a whole range of MSDs. It has been well established in previous studies that there is a strong association between MSD and the clinical burdens of dental practitioners [10–13]. A previous review in this area discovered that 64%–93% of dental professionals suffer from general work-related MSD [10], representing a significant proportion of the workforce. This can have overall detrimental effects on the industry’s work force, resulting in lower productivity, increased sick leave and early retirement from the profession [1]. There is also some evidence to suggest that MSD can develop in students during their education and training [14–18]. This may be attributed to the pressures of tertiary study and the physical burden of clinical training. With increasing numbers of students, and therefore professionals, in the dental health industry, it is crucial to determine the prevalence and address the aetiology of MSD involved with this profession. Despite a widespread awareness of this occupational health burden, a recent literature review found that dental professionals continue to suffer from MSD at alarming rates [13]. Research suggests that symptoms may arise during the education and training of students [14,15]. Students are taught and are aware of the risks of MSD during the early phase of their training, but over time, less emphasis is given to this occupational health issue [16]. Research in this area has improved in recent years; however, there have only been a limited number of studies in Australia [19]. Studies also focus more on professionals in the industry rather than students. Dental and oral health students are a useful group to research as it is logical to hypothesise that symptoms may potentially arise during this educational phase of dental professionals. With an ever-increasing student population and, subsequently, registered professionals in the field of oral health and dentistry in Australia, research would be crucial in understanding potential occupational health problems as well as providing support for further research into MSD in the related dental professions. Thus, the aim of this study was to determine the prevalence of musculoskeletal pain and postural deficits in dental and oral health students and to investigate any risk factors that may influence the rate of MSD in this population. This will be achieved by: a. b.
Measuring MSD prevalence using a self-administered questionnaire Posture assessment
2. Methods This study was carried out as descriptive and exploratory research, using a cross-sectional approach. The study examines the prevalence of MSD in students studying the Bachelor of Oral Health (BOH) and Doctor of Dental Surgery (DDS) degrees at the University of Melbourne, Australia. The study duration of the BOH and DDS, respectively, are three and four years to completion. In addition to assessing the prevalence of MSD, the study also conducted an assessment of posture as an influencing factor of MSDs. A cross-sectional design was selected as this was identified as the most appropriate method to answer the research question. Cross-sectional studies measure exposures and outcomes at a single point in time, and, as such, are useful for yielding prevalence estimates. This study design is efficient in terms of cost and time, as it allows several factors to be studied; given that this project is required to be completed in less than 12 months, a cross-sectional approach was considered the most appropriate choice. Ethics approval was obtained from the University of Melbourne in August 2015.
Healthcare 2016, 4, 13
3 of 15
The questionnaire was two pages long and included a plain-language statement explaining the Healthcare 2016, 4, 13 3 of 14 study; consent was implied by completing the questionnaire. The questionnaire was an adapted version of an original tool by Smith and Leggat [20] that has been previously used among medical, version of an original tool by Smith and Leggat [20] that has been previously used among medical, Healthcare 2016, 4, 13 3 of 14 dental, nursing and occupational therapy students, as well as dental hygienists and dentists [10,21], dental, nursing and occupational therapy students, as well as dental hygienists and dentists [10,21], andand takes less than five minutes to complete. takes less than five minutes to complete. version of an original tool by Smith and Leggat [20] that has been previously used among medical, Students were invited to participate a postural assessment, were given a consent Students were alsoalso invited to participate in ain postural assessment, andand were given a consent dental, nursing and occupational therapy students, as well as dental hygienists and dentists [10,21], Healthcare 2016, 4, 13 3 of 14 form to complete and return should they wish to participate. The postural assessment used was the form to complete and return should they wish to participate. The postural assessment used was and takes less than five minutes to complete. the Branson’s Dental Operator Posture Assessment Instrument (Table 1) [22], and was conducted during Branson’s Dental Operator Posture Assessment (Table 1) [22], and wasgiven conducted Students were also invited to participate in Instrument a postural assessment, and were a consent version of an original tool by Smith and Leggat [20] that has been previously used among medical, a timetabled clinical or pre‐clinical scaling session, with assessment done by the student researcher. during a timetabled clinical or pre-clinical scaling session, with assessment done by the student form to complete and return should they wish to participate. The postural assessment used was the dental, nursing and occupational therapy students, as well as dental hygienists and dentists [10,21], Scores ranged from 10 to 194, with the lowest score being the most ideal. From the scores, participants’ researcher. Scores ranged from 10 to 194, with the lowest score being the most ideal. From the scores, Branson’s Dental Operator Posture Assessment Instrument (Table 1) [22], and was conducted during and takes less than five minutes to complete. postures postures were categorised as Acceptable, Compromised or Harmful. These categories can participants’ were categorised Acceptable, or Harmful. These can be a timetabled clinical or pre‐clinical scaling session, with assessment done by the student researcher. Students were also invited to as participate in Compromised a postural assessment, and were categories given a consent interpreted as follows: be interpreted as follows: Scores ranged from 10 to 194, with the lowest score being the most ideal. From the scores, participants’ form to complete and return should they wish to participate. The postural assessment used was the
postures were (10–40): categorised as in Acceptable, Compromised or operator Harmful. These categories can be Branson’s Dental Operator Posture Assessment Instrument (Table 1) [22], and was conducted during Acceptable Acceptable (10–40): Postures in this category will not put the operator at risk for musculoskeletal Postures this category will not put the at risk for musculoskeletal interpreted as follows: a timetabled clinical or pre‐clinical scaling session, with assessment done by the student researcher. discomfort or cumulative trauma disorders. ➢ discomfort or cumulative trauma disorders. Scores ranged from 10 to 194, with the lowest score being the most ideal. From the scores, participants’ Compromised (41–80): Postures in this category, if held for more than five minutes repeatedly Compromised Acceptable (10–40): Postures in this category will not put the operator at risk for musculoskeletal (41–80): Postures in this category, if held for more than five minutes repeatedly postures were categorised as put Acceptable, Compromised or Harmful. These categories can be throughout the work day, will the operator risk for musculoskeletal or discomfort or cumulative trauma disorders. ➢ throughout the work day, will theput operator at risk for at musculoskeletal discomfort or discomfort cumulative interpreted as follows: cumulative trauma disorders. trauma Compromised (41–80): Postures in this category, if held for more than five minutes repeatedly disorders. Harmful (81–194): Posture in this category, if held for any length of time, will put the operator throughout the work day, will category, put the ifoperator at risk for of musculoskeletal discomfort Harmful Acceptable (10–40): Postures in this category will not put the operator at risk for musculoskeletal (81–194): Posture in this held for any length time, will put the operator or at risk for cumulative trauma disorders or injury. discomfort or cumulative trauma disorders. ➢ atcumulative trauma disorders. risk for cumulative trauma disorders or injury. Harmful (81–194): Posture in this category, if held for any length of time, will put the operator Compromised (41–80): Postures in this category, if held for more than five minutes repeatedly Table 1. Branson’s Dental Operator Posture Assessment Instrument (PAI). at risk for cumulative trauma disorders or injury. throughout the work day, will Operator put the Posture operator at risk Instrument for musculoskeletal discomfort or Table 1. Branson’s Dental Assessment (PAI). Acceptable Compromised Harmful 1 min 3 min 5 min Total cumulative trauma disorders. Table 1. Branson’s Dental Operator Posture Assessment Instrument (PAI). HIPS Acceptable Compromised Harmful 1 min 3 min 5 min Total Harmful (81–194): Posture in this category, if held for any length of time, will put the operator Level on stool Hips not level on stool HIPS Acceptable Compromised Harmful 1 min 3 min 5 min Total at risk for cumulative trauma disorders or injury. (1 POINT) (2 POINTS) HIPS Level on stool Hips not level on stool TRUNK (1 POINT) (2 POINTS) Level on stool Hips not level on stool Table 1. Branson’s Dental Operator Posture Assessment Instrument (PAI). Front to back ≤20° Front to back >20°, 20°, 20˝ , 20°, 20˝ , 20°, 20°, 20°, 20˝ , 20°, 20°, 20°, 20°, 20 , 20°, 20°, 20 , 20°, 20°, 20°, 20˝ , 20°, 20°, 20°, 2 Days Affected daily life Needed treatment
33.3 50 0 0
68.8 36.4 18.2 0 Shoulders
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
50 44.4 44.4 22.2
31.3 60 20 0 Upper Back
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
38.9 28.6 28.6 42.9
50 62.5 50 12.5 Elbows
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
0 0 0 0
5.6 0 0 0 Forearms
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
5.6 0 0 0
12.5 50 50 50 Wrists/Hands
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
44.4 25 25 0
50 25 25 12.5
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Table 5. Prevalence of MSD by lower body region. Reported MSD (% Students) Cohort
BOH1
BOH3
DDS1
DDS4
44.7 50 29.4 5.9
64 62.5 25 18.8
6.6 60 60 40
3.8 0 0 0
14.5 63.6 45.5 18.2
7.7 100 0 0
3.9 33.3 33.3 0
11.5 33.3 0 0
6.25 100 0 0
15.4 100 25 25
Lower Back Any symptoms Persisted > 2 Days Affected daily life Needed treatment
33.3 66.7 66.7 33.3
62.5 50 30 20 Hips/Thighs
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
0 0 0 0
18.8 100 66.7 33.3 Knees
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
11.1 50 50 50
6.25 100 100 100 Calves/Lower Leg
Any symptoms Persisted > 2 Days Affected daily life Needed treatment
5.6 0 0 0
0 0 0 0 Ankles/Feet
Any symptoms Persisted > 2 Days Affected daily life Healthcare 2016, 4, 13 Needed treatment
5.6 100 100 0
5.3 75 25 0
7 of 14
MSD Prevalence between Cohorts 80
*
No. of Students (%)
70 60 50 40
*
30 20 10 0 Neck
Shoulder
Upper Back
Wrist/Hands
Lower Back
Body region BOH1
BOH3
DDS1
DDS4
Figure 1. MSD prevalence of body regions between the cohorts studied. * p-value < 0.05. Figure 1. MSD prevalence of body regions between the cohorts studied. * p-value < 0.05.
Statistical Statistical correlates correlates of of MSD MSD were were differentiated differentiated into into two two tables, tables, with with the the predictors predictors shown shown in in Table 6 and the protective factors shown in Table 7. Table 6 and the protective factors shown in Table 7. Table 6. Statistical correlates and predictors of MSD. Body Region
Predictor Female DDS course
OR * 1.98 1.83
(95% CI) 0.98–3.99 1.22–2.75
SEM 0.71 0.38
p-Value 0.05 0.003
Healthcare 2016, 4, 13
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Table 6. Statistical correlates and predictors of MSD. Body Region
Predictor
OR *
(95% CI)
SEM
p-Value
Neck
Female DDS course DDS1 cohort BOH3 cohort No Loupes Computer type (Laptop) No previous practitioner experience Usage environment (Desk) Low preclinical hrs/week
1.98 1.83 4.08 4.4 1.52 1.64 1.54 1.73 1.88
0.98–3.99 1.22–2.75 1.37–12.14 1.04–18.59 1.03–2.25 1.14–2.35 1.04–2.28 1.07–2.80 1.16–3.05
0.71 0.38 2.27 3.24 0.3 0.3 0.31 0.43 0.47
0.05 0.003 0.012 0.044 0.034 0.008 0.032 0.026 0.011
Low clinical hrs/week Female Usage environment (Table) Stress (high) High clinic hrs/week
1.7 2.27 1.35 5.19 2.29
1.08–2.67 1.12–4.61 1.02–1.79 1.86–14.54 1.13–4.62
0.39 0.82 0.19 2.73 0.82
0.021 0.022 0.038 0.002 0.021
Shoulder Upper Back Wrists/Hands Lower Back
Note: *Odds ratio.
Table 7. Statistical correlates and predictors for non-reporting of MSD. Body Region
Predictor
OR *
(95% CI)
SEM
p-Value
Shoulder
Male Low computer usage (hrs/week)
0.49 0.37
0.28–0.84 0.15–0.88
0.14 0.16
0.01 0.024
Upper Back
DDS course Male Low alcohol consumption No previous practitioner experience Low clinical hrs/week No Loupes Usage environment (Desk)
0.52 0.53 0.52 0.58 0.5 0.58 0.43
0.35–0.79 0.31–0.90 0.35–0.79 0.39–0.86 0.32–0.79 0.39–0.86 0.27–0.68
0.11 0.15 0.11 0.12 0.12 0.12 0.1
0.002 0.02 0.002 0.007 0.003 0.007
