Occupational health specialists Pippa Stanford and Anne Harriss outline a case study that considers the impact of a lumbar disc prolapse on a professional horse rider in relation to his fitness to work.
Musculoskeletal disorders (MSDs), including back pain, are the most commonly reported cause of work-related ill health in the UK. They affected around one million people in 2005/06, with time off work estimated at 9.5 million working days (Bevan, 2007). Palmer et al (2007) suggested that between 60% and 80% of the population will experience low back pain at some point in their lifetime, with between 14% and 40% having symptoms of sciatic leg pain. It is therefore a significant workplace issue.
Risk factors for MSDs include manual handling of loads, awkward postures and a prior or current injury (Health and Safety Executive, 2004; Adams and Dolan, 2005). Kumar and Clark (2009) suggest that acute lumbar disc prolapse occurs suddenly through mechanical factors, such as bending, twisting and lifting. Notwithstanding this, there is evidence to show that personal risk factors may predispose individuals to low back pain and spinal tissue damage (Adams and Dolan, 2005).
Adams and Dolan (2005) found that most people in high-risk occupations tend to be unaffected by back pain, proposing that those who are physically active have stronger discs and vertebrae. However, changes in spinal tissues, including the discs, occur with age and may result in less resistance to high compressive stress potentially arising during heavy manual handling tasks (Adams et al, 1996; Bogduk, 2002; Oliver and Middleditch, 2004).
Disc degeneration may result from hereditary factors (Oliver and Middleditch, 2004) and smoking (Adams and Dolan, 2005) compounding an injury to a vertebral body, with males aged between 30 and 50 years at higher risk of disc prolapse (Adams et al, 2006). Further, individuals who are overweight may be at higher risk of disc disease (Kasper et al, 2005).
Psychosocial factors, including negative feelings about work or a tendency towards depression, may also contribute or exacerbate MSDs (Health and Safety Executive, 2004; Adams and Dolan, 2005).
This case study examines the impact of intervertebral disc prolapse on the ability of a professional horse rider to carry out his work. It includes the assessment of fitness to work with a view to resuming his work responsibilities. It also explores the pathophysiology of inflammatory changes associated with this disc prolapse and then highlights the assessment of the client's fitness to work.
Sam (pseudonym) is aged 48 and has been a professional horse rider since his late teens, loves his work and has a positive attitude to life. As a consequence of a prolapsed intervertebral disc he was experiencing pain in his lower right leg and foot preventing him from riding. He was referred to the OH nurse for an assessment of his fitness for work.
Sam had no previous history of MSDs and minimal previous sickness absence. He is slim, physically active and a non-smoker; smoking is a risk factor for inter-vertebral disc pathology. Predisposing factors included his age and features of his job requiring awkward postures and heavy manual handling tasks.
Sam identified no specific trigger to his symptoms. An MRI scan revealed a large L4/5 intervertebral disc prolapse, with a sequestrated fragment and right L5/S1 radicular pain. This resulted in both sensory and motor deficits, as described by Porth (2007), with pain in his outer right calf and foot, plus numbness into his toes, combined with generalised lethargy.
Musculoskeletal disorders, including back pain, are the most commonly reported cause of work-related ill health in the UK."
Sam's ability to carry out activities of daily living, such as household chores and caring for himself, was not significantly impaired by his symptoms as he could perform these at his own pace. Most significantly, his sleep was poor due to his pain, which increased on changing position.
However, in relation to the very physical demands of his work, Sam's symptoms posed a significant problem preventing him from riding, walking quickly and running when leading horses.
Lumbar intervertebral disc
In the structure of the intervertebral disc, the inner layers of the lumbar intervertebral discs lack innervation. The sinuvertebral nerve, which is a mixed autonomic and somatic nerve, supplies the posterior and posterolateral annulus fibrosus predominating in the outer third of the annulus fibrosus, with fewer nerves on the middle third and none in the inner third and nucleus pulposus (Bogduk, 2002; Adams et al, 2006). It is therefore possible that Sam had sustained an asymptomatic annular tear present prior to the development of his pain, consistent with the findings of MRI studies, of Jensen et al (1994). Up to one-third of people will have an asymptomatic disc herniation. Ohnmeiss (1999) proposed that a full annular tear would result in an absence of intra-discal pressure, thereby resulting in an absence of pain.
Sam's ensuing disc prolapse became symptomatic during the period in which he was breaking in yearlings, possibly resulting from fatigue failure of the anterior and posterior longitudinal ligaments compounded by sustained spinal flexion (Waddell, 2004). Body tissue responds to injury through inflammation, resulting in swelling, pain and loss of function (Woolf, 2000; Porth, 2007).
Signs and symptoms of a herniated disc are localised to the area innervated by the affected nerve roots (Porth, 2007). However, it is possible that lumbar disc herniation may irritate or compress more than one root. This is because the lower level lumbar nerve roots, collectively known as the cauda equina, are structured closely together so that more than one nerve root may be irritated or compressed. This can result in pain radiating along the sensory distribution or dermatome of the nerve root, which may not match the exact spinal root dermatomal distribution (Gillard, 2005) as in Sam's case.
Assessment of fitness to work
Sam consented to a prompt management referral to the OH nurse in order to limit his sickness absence and devise an active rehabilitation programme at the appropriate time, as advocated by Palmer et al (2007).
The aim of the assessment was to ensure Sam was able to carry out work tasks without risking his health and safety or that of others. It incorporated a general framework which took account of Sam's job requirements (Palmer et al, 2007). The assessment framework of Murugiah et al (2002) was utilised in the assessment.
This model considers four variables (see box): personal attributes; work characteristics; work environment; and legal aspects. It supports a comprehensive and fair approach to assessment, facilitates clear decision-making and takes into account the needs of both the employer and employee.
All four variables were addressed and with regard to personal attributes, factors including past medical history were recorded and there were no obvious links to the existing diagnosis. Sam's positive attitude to life and work and his desire to return to riding were noted. Ignoring psychosocial factors may have resulted in a longer absence from work should Sam have become low in mood or had concerns over his work.
The location of his pain was recorded and it was noted that he had no "red flag" problems associated with micturition (urination), faecal incontinence or saddle anaesthesia, constituting some of the features of cauda equine syndrome (Palmer et al, 2007). Such symptoms would have initiated immediate onward referral by the OH nurse for urgent medical attention.
Sam's GP had already referred him for physiotherapy and to a spinal specialist who ordered an MRI scan, giving rise to his diagnosis. His treatment plan involved a spinal injection for symptom relief. Sam had also been prescribed Diclofenac and Tramadol. As his symptoms settled, the need to reduce medications with the potential to mask symptoms was discussed, as were the sedative effects of Tramadol as this medication could put Sam at risk when he needed to be alert to maintain his safety.
Detailed notes of advice given by the various healthcare practitioners involved in Sam's care were documented, demonstrating collaborative working and joint decision-making (Murugiah et al, 2002). The importance of collaborative working is highlighted by both the Department of Health (2003) and the Department for Work and Pensions (2008).
The spinal specialist indicated that following the spinal injection Sam should take a minimum of seven days to recuperate prior to returning to work. Sam's physiotherapist was consulted when planning the phased and graded return-to-work plan that was discussed with Sam and agreed by his manager. A further occupational health review date was identified.
Fitness to work: framework of assessment
- Skill levels.
- Technique, speed, etc.
- Past experience.
- Physical attributes.
- Psychological attributes.
- Task posture(s).
- Mechanical load.
- Sedentary, active.
- Work-pause sequence.
- Potential risks of exposure to workplace hazards.
- Ambient temperature.
- Welfare facilities, catering.
- Characteristics of the workplace.
- Common law.
- Statutory law.
- Regulations, eg Equality Act, health and safety legislation.
- Codes of practice.
The return-to-work strategy that was devised matched Sam's job requirements and involved a risk assessment that took account of the tasks he undertook. It recognised the ergonomic elements of his job requirements, including "work-associated" postures and tasks associated with equine management such as riding and the handling of loads. A clear audit trail of correspondence between the OH nurse and the employer reporting on Sam's progress in relation to his fitness to work was maintained. All advice took into account both the business objectives (Oakley, 2008) and the essential job requirements of a rider/groom.
The assessment included the impact of Sam's pain on activities of daily living, home and working life; having an overall picture of the client's abilities underpins advice that is given by the OH nurse. Not only were his pain and lethargy affecting his ability to carry out his job, but he was also unable to walk his dogs and could drive only short distances.
An understanding of the work environment was achieved by workplace visits; a risk assessment of his job role underpinned the assessment of Sam's health status. The implications of Sam's inability to move quickly, putting both Sam and his colleagues at risk in the event of an incident with a "badly behaving" horse requiring restraint were documented.
In Sam's organisation, it is a requirement that a rider is able to ride "'one lot" minimum per day on return to work following sickness absence, a "lot" constituting exercising or breaking in a particular horse and lasting approximately forty-five minutes. A key consideration therefore is the significant level of fitness that the rehabilitating rider needs to have on returning to work. "Lighter duties" are not a feature of such work and temporary redeployment to an office setting is generally not an accepted option.
The phased return-to-work plan was structured over a four-week timeframe, building up by one lot per week to the maximum four "lots" daily by week four, as long as Sam experienced no adverse reactions. In this event the plan would have been reviewed in consultation with his doctor. Ongoing communication and explanation to Sam's manager were important, so that the gradual reintroduction to riding was accepted with the view that it was likely that Sam would be able to fulfil the substantive requirements of his job description by the end of this period.
Regular contact was maintained with Sam until his return to work, helping him to avoid feelings of isolation and promote an effective return-to-work strategy. As his symptoms settled, basic physical and functional assessments were undertaken to establish if he could achieve postures relating to the job requirements, for example crouching to bandage a horse's leg. Comparisons could be then be made at subsequent reviews.
Safer postures were taught via job-specific manual-handling training, carried out by the OH nurse in her role as educator (World Health Organisation, 2001). This was recorded in the notes and notified in a review sent to the employer. The outcome was successful with Sam returning to his role as rider groom after a period of three months.
Sam's initial assessment and subsequent reviews were documented in detail. He had consented to reports being submitted to HR and management. He was given a copy of this report, which was discussed with him, and he consented to the release of this information, which included information regarding his health status in relation to being able to carry out his job requirements safely and effectively.
A successful phased return to work was possible only by effective communication and consultations."
Clinical assessment relating to Sam's fitness for his job was quite detailed and the rationale was evident at initial assessment and subsequent reviews for the OH nurse's decisions in relation to his ability to carry out the essential tasks of his job. There was a clear audit trail showing that Sam was consistently involved in the assessment process, his signature being on his notes to show agreement along with a signed consent form for the release of reports to management, which were also copied to him. Additionally, there was evidence of collaborative working and joint decision-making both with HR, management and those involved in his care.
Assessment and advice given to both Sam and his manager took into account legal duties, relating to the employer and employee meeting the requirements of the Health and Safety at Work Act (Great Britain Parliament, 1974) and other relevant health and safety Regulations, including the management Regulations and moving and handling Regulations. These were of particular importance given the demands and hazardous nature of Sam's work responsibility.
A successful phased return to work was possible only by effective communication and consultations with Sam, members of his healthcare team and his manager. The strategy that was developed was matched to Sam's improving functional capacity, taking careful consideration of his job requirements. This approach was integral to a successful return to work. Meeting both the organisation's business needs and demonstrating that good occupational health support adds value to the organisation reinforces the fact that good health is good business.
Pippa Stanford, RGN AssocCIPD CertEd MIfL FRSPH, is a freelance occupational health nurse and occupational health adviser, and managing director of Health 1st Ltd.
Anne Harriss is programme director - occupational health nursing and workplace health management - and reader in educational development, London South Bank University.
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