Work related musculoskeletal disorders (WMSD) are an important occupational health issue among all health care workers. WMSD is a collective and descriptive term for the symptoms caused or aggravated by work and characterized by discomfort, impairment, disability or persistent pain [1]. Epidemiological and ergonomic WMSD research has captured a prominent position in the arena of occupational health due to the substantial financial cost and decreased productivity among employers and employees [2]. Nurses are part of the multi-disciplinary medical team at hospitals and other medical centers that are susceptible to WMSD [3,4].

Consequences of WMSD among professional nurses are increased number of sick days per year, premature retirement and poor health [3,4]. Grabbe et al. reported that 56% of all sick days among professional nurses were due to WMSD5. Trinkoff et al. reported that nurses cite WMSD, strenuous work and psychology demands are the key triggers to premature retirement [5,6]. The lower back has been identified as the most vulnerable anatomical site of WMSD among the nursing fraternity [7,8]. In the last two years (2012-2013) there has been four systematic reviews published relevant to this topic [6-9]. Yassi and Lockhart systematic review concluded a causal relationship between nursing tasks and lower back pain [9]. Their systematic review scrutinized studies published during 1980-2012 (89 articles) [9]. Whilst Schlossmacher and Amaral systematically reviewed the methods of evaluating low back injury caused by unfavorable working conditions among nurses [7]. Schlossmacher and Amaral review examined only 12 articles [7]. Long et al. reviewed the risk factors and functional consequences of work related upper quadrant musculoskeletal disorders among midwives, nurses and physicians [6]. Long et al. examined 18 studies published during 1993-2010 [6]. The aim of this paper was to review current literature pertaining to WMSD among nurses at all anatomical sites during 2003 to 2013. This is the only systematic review that describes the kinesiology of prolonged vertebral flexion adopted by nurses during patient transfer activities. Further, the gynoid somatotype is discussed as a primary intrinsic predisposing risk factor of lower back pain and injury among nurses. Exclusive to this systematic review is the examination of different intervention strategies adopted to curb the occurrence of work related musculoskeletal disorders among nurses, specifically physical exercise/ therapy. Authors’ reviews of the findings of physical therapy as a treatment modality of WMSD among nurses are most favorable. Although this feasible solution may have been uncovered, due to the multi-factorial nature of the nursing profession, it may not be suitable.

The authors followed standard practices for systematic reviews (PRIMSA) [10]. In regards to defining the participants, interventions, comparisons, outcomes and study designs (PICOS) according to PRIMSA checklist guidelines, the participants were professional nurses, the intervention is not a therapeutic intervention but is interpreted as an exposure; namely performing nursing duties, the comparison in various articles in this review were comparisons to the general population at large, outcome of interest was (i) WMSD symptoms, musculoskeletal disorders, incidence and prevalence of WMSD in the previous 12 months and point prevalence, (ii) functional consequences of these symptoms on the affected individual in relation to their occupational, and, (iii) symptoms attributable to the individual’s occupational activities and environment (not to trauma sustained from leisure activities). Reporting of the associations to WMSD was; risk factors associated to WMSD and anatomical site of injury and/or pain. The exclusion criteria were; (i) publications prior 2003, and (ii) publications of healthcare personnel and/or staff, who were not nurses.

A literature search and selection of peer-reviewed and professional journal publications were conducted, in the following search engines; PubMed, Medline, Science Direct, Ebscohost, Biomed, CINAHL and Embase (Figure 1). Key search words were: nurses, WMSD, occupational injury, musculoskeletal disorders, musculoskeletal symptoms, occupational epidemiology and intervention. The inclusion criteria for publication selection were: professional nurses.

Figure 1: Study selection process

Forty-eight English publications were identified, however after stringent evaluation according to the exclusion criteria only 27 publications were utilized for this review. The sum of the all nurses involved in these investigations was 13317. There was 71.85% prevalence of WMSD. The result of the literature search is synthesized into five tables. Table 1 describes the systematic review of the last four publications [6-9]. Table 2 describes the chronological overview of WMSD among nurses specific to anatomical sites and identifying predisposing risk factors during the period of 2003-2013 [10-23].

Table 1: Systematic review of WMSD among nurses (2012-2013)

Table 2: Chronological overview of the WMSD among nurses specific to anatomical sites, identifying predisposing risk factors (2003-2013)

Table 3 provides an overview of the comparative studies between nurses and other populations in relation to WMSD during the period 2006-2013 [24,25]. Table 4 defines the overview of the longitudinal studies of WMSD among nurses during 2003-2008 [3,26,27]. Table 5 describes the different intervention studies that attempted to curb WMSD among nurses during 2003-2013 [28-31].

Table 3: Overview of the comparative studies between nurses and other population in relation to WMSD (2006-2013)

Table 4: Overview of the longitudinal studies of WMSD among nurses (2003-2008)

Table 5: Overview of the intervention studies that attempted to curb WMSD among nurses (2003-2013)

The results will be discussed in the following headings; anatomical site of WMSD, risk factors predisposing nurses to WMSD and physical activity intervention programs.

Anatomical sites of WMSD

The most vulnerable anatomical site of WMSD were; vertebral column, followed by shoulders, neck, knee, ankles/feet, wrist, thighs and elbow [11-23]. Further stratification of the prevalence of the vertebral column revealed the lower back to most susceptible to WMSD followed by the neck, upper back and pelvic complex (hips) [13-18]. Lower back WMSD had 53.24% prevalence among the publications. The predisposing mechanism of lower back WMSD will be discussed later.

Risk factors predisposing nurses to WMSD

Risk factors were divided into extrinsic and intrinsic factors. The extrinsic factors included the following:

i) Physical demands of the nursing profession include bending and twisting [23,24]

ii) Physical demands of nurse-patient interaction include; turning, bathing, dressing, seating the patient in the bed and/or chair and transferring the patient. There were different tasks: stretcher to bed, bed to chair, bed to toilet [21,22].

Anap et al. postulated that the above mentioned physical tasks do contribute to the prevalence of WMSD [24]. Many of the above tasks require the nurse to alter her body position from the anatomical ideal posture to ensure that the task is completed successfully [23]. In addition many tasks require the nurse to maintain these deviated postural alignments for prolonged periods of time which increases the risk of WMSD [16,23,25]. Transferring of patients requires the nurse to flex their vertebral column for prolonged duration, exerting isometric muscle contraction to maintain their static posture or to slowly lower a heavier patient to the chair (eccentric muscle contractions) [30].

Maintaining these deviated postures for prolonged periods daily, produces abnormal force couple relationships among the paraspinal musculature, producing muscle damage [8,26]. Many nurses do not practice proper lifting techniques when transferring patient (they do not bend their knees and brace their lower back) [30,31]. Poor lifting technique practiced by nurses when transferring patients, places excessive stress on their lower back facilitating lower back musculoskeletal injuries [13,14].

Intrinsic risk factors pertain to nurse’s characteristics.

The primary intrinsic risk factor is obesity of nurses [17,19],

A second intrinsic risk is the poorly conditioned status of nurses [19]

The primary intrinsic predisposing risk factor of lower back injury among nurse is related to their genoid somatotype of obesity [30]. Gynoid somatotype is commonly described as a pear shaped, where the increased accumulation of body fat is found around the waist and hips. Literature reports that nurses’ average body mass index is 31.7 kg/m² that exceed the ACSM guidelines [19]. Naidoo and Coopoo correlated the genoid somatotype of obese nurses to the prevalence of lower back injuries which is supported by Choobineh et al. [17,19]. The excess body fat around the waist and hip causes anterior pelvic tilt which produces an abnormal force couple relationship between the hip extensors and flexors. Hip flexors became tight while the hip extensors are elongated and weaker [33]. Smedley et al. reported that nurses were poorly conditioned when compared to general population [30]. In a physically demanding occupation poor physical condition increases the risk of WMSD [19,30].

Physical activity intervention programs

There is limited literature pertaining to the impact that physical activity acts as a protective measure against WMSD when adhered to by nurses [29-32]. Yuan et al. documented that nurses who regularly participate in physical activity and exercise lower their risk of WMSD [32]. Proper et al. and Warming et al. supported the notion that physical therapy (exercises) is a strong therapeutic modality to resolve the symptoms of lower back injuries and enhances quality of life [29,31]. However the primary limitation to adherence to regular physical activity participation among nurses due to their lack of time [3,4]. Generally nurses work long hours each day (ranges from 8-12 hours) thereby providing limited or no time for physical activity [20]. It has been recommended by Proper et al.to implement health and wellness programs at the nurses’ occupational environment [29]. In addition the employer should make provision in the nurses’ daily occupational activity to adhere to a well prescribed physical activity programs [29].

The efficacy of lumbar stabilization exercises for patients with musculoskeletal lower back pain (MLBP)

Common signs and symptoms of MLBP are para-spinal and abdominal muscle atrophy, deceased lumbo-pelvic hip complex (core) strength and endurance, decreased and poor synchronization of neural firing, poor proprioception [34-37]. In order for lumbar stabilization exercises to be considered an effective therapeutic intervention to combat MLBP, it has to negate the aforementioned common signs and symptoms.

Lumbar stabilization exercises are instrumental in producing paraspinal muscle hypertrophy, increased strength and endurance [35-37]. Hides et al. demonstrated that lumbar stabilization exercises prevent recurrent MLBP by nine-time less in patients who adhere to core stabilization programs in comparison to those patients who do not [36]. O’ Sullivan et al. reported when spondlylolysis and spondlyliothesis patients adhered to a lumbar stabilization exercise programs, their lower back pain was decreased, function and quality of life improved [37].

One of the earliest benefits derived from an exercise stability programs is enhanced neuromuscular efficiency [34]. In fact improvements in neuromuscular efficiency occur before muscle hypertrophy. Exercise physiologists attribute the early gains in muscle strength and endurance is due to enhanced neuromuscular efficiency [34]. The enhanced neuromuscular efficiency occur due to; (i) increase in the number of motor units being recruited during muscle contractions, (ii) increased firing rate of each motor unit, and, (iii) improved synchronization of motor units firing [33].

Other intervention to combat WMSD among nurses

Smith et al. reported that Chinese nurses resorted to regular alcohol consumption to help cope with pain of WMSD [13]. This intervention has its obvious malady to alcoholism and chronic diseases.

Ergonomic-education on the application of proper patient transfer techniques has been an idea which received considerable attention. Engkvist et al. has identified poor patient transfer technique has the primary culprit of lower back pain among nurses [17,28]. However, Warming et al. reported that education on the application of proper patient transfer to nurses did not eliminate the incidence of lower back pain [31]. There is a need for other intervention studies to be conducted to provide clinical empirical evidence of its value in combating WMSD.

This systematic review has identified that nurses are vulnerable to WMSD, especially lower back pain and injury. The predisposing risk factors of lower back pain and injury are poor patient transfer technique, high physical demand of the nursing profession, poor conditioning status of the nurses, obesity. A primary limitation of this review is the limited number experimental intervention studies that have been conducted to combat the WMSD among nurses. The only intervention that seems to alleviate lower back pain and injury among nurses is the adherence to a regular supervised exercise programs however nurses are not keen to adopt this intervention strategy. Further research should be conducted to determine other intervention strategies to negate WMSD among nurse, which they will adhere too.