Alison H. McGregor

Lower limb involvement in spinal function and low back pain.

AIMnTo evaluate evidence for involvement of the lower limb in spinal function and low back pain (LBP).nnnDESIGNnA hypothesis based on a critical review of the relevant biomechanical and clinical literature.nnnRESULTSnThe spine resembles an inverted pendulum that supports the weight of the upper body; its stability requires a moving base that is provided by the joints of the lower limb, especially the hip. However, the sacroiliac joints are unlikely to be important for spinal function. The changing pattern of gait and development of lumbar lordosis, in early childhood, provide evidence for the inter-dependence of spinal curvature and lower limb action. Clinical signs associated with LBP may be associated with an inability to rotate the trunk about the hips. These include disorientation of the pelvis and weakness or tightness of muscles around the hip. The sway back posture seen in LBP involves flexion of the hip, knee and ankle to compensate for abdominal and back muscle weakness.nnnCONCLUSIONSnIn order to understand the varied clinical presentation of LBP patients, the function of the spine should be considered in the context of the whole body, especially the lower limb.

The development of an evidence-based patient booklet for patients undergoing lumbar discectomy and un-instrumented decompression

Post-operative management after lumbar surgery is inconsistent leading to uncertainty amongst surgeons and patients about post-operative restrictions, reactivation, and return to work. This study aimed to review the evidence on post-operative management, with a view to developing evidence-based messages for a patient booklet on post-operative management after lumbar discectomy or un-instrumented decompression. A systematic literature search produced a best-evidence synthesis of information and advice on post-operative restrictions, activation, rehabilitation, and expectations about outcomes. Evidence statements were extracted and developed into patient-centred messages for an educational booklet. The draft text was evaluated by peer and patient review. The literature review found little evidence for post-operative activity restrictions, and a strong case for an early active approach to post-operative management. The booklet was built around key messages derived from the literature review and aimed to reduce uncertainty, promote positive beliefs, encourage early reactivation, and provide practical advice on self-management. Feedback from the evaluations were favourable from both review groups, suggesting that this evidence-based approach to management is acceptable and it has clinical potential.

National audit of post-operative management in spinal surgery

BackgroundThere is some evidence from a Cochrane review that rehabilitation following spinal surgery may be beneficial.MethodsWe conducted a survey of current post-operative practice amongst spinal surgeons in the United Kingdom in 2002 to determine whether such interventions are being included routinely in the post-operative management of spinal patients.The survey included all surgeons who were members of either the British Association of Spinal Surgeons (BASS) or the Society for Back Pain Research. Data on the characteristics of each surgeon and his or her current pattern of practice and post-operative care were collected via a reply-paid postal questionnaire.ResultsUsable responses were provided by 57% of the 89 surgeons included in the survey. Most surgeons (79%) had a routine post-operative management regime, but only 35% had a written set of instructions that they gave to their patients concerning this. Over half (55%) of surgeons do not send their patients for any physiotherapy after discharge, with an average of less than two sessions of treatment organised by those that refer for physiotherapy at all. Restrictions on lifting, sitting and driving showed considerable inconsistency both between surgeons and also within the recommendations given by individual surgeons.ConclusionDemonstrable inconsistencies within and between spinal surgeons in their approaches to post-operative management can be interpreted as evidence of continuing and significant uncertainty across the sub-speciality as to what does constitute best care in these areas of practice. Conducting further large, rigorous, randomised controlled trials would be the best method for obtaining definitive answers to these questions.

Establishment of a protocol to test fatigue of the trunk muscles

Background: Muscle fatigue has high relevance in human performance yet little research has evaluated how it should be assessed. Objective: To perform a pilot study to identify suitable methods of generating and assessing fatigue of the trunk flexor and extensor muscles. Methods: Sixteen university rugby players (mean (SEM) age 21.9 (0.2) years) were recruited and subjected to four protocols (A, B, C, D), separated by a week to allow recovery, with peak torque being recorded during each test: A, isokinetic measurements before and after fatigue, with a 10 repetition isokinetic fatigue period; B, isokinetic measurements before and after fatigue with a 45 second isometric fatigue period; C, isometric measurements before and after fatigue with a 10 repetition isokinetic fatigue period; D, isometric measurements before and after fatigue with a 45 second isometric fatigue period. All were conducted during flexion and extension of the trunk on the Cybex Norm Isokinetic Dynamometer trunk flexion-extension unit. Results: All subjects completed all four protocols. Fatigue induction appeared more effective in flexion than extension. Significant differences in mean peak torque before and after fatigue were seen in protocols A, B, and D in flexion and only in protocol D for extension. In flexion, protocol D produced the greatest fatigue, peak torque being 16.2% less after than before fatigue, suggesting greatest sensitivity. Conclusions: Protocol D, which incorporates isometric testing and fatigue protocols, appears to be able to produce fatigue most effectively, and therefore may provide the most valid assessment of fatigue in the trunk flexor and extensor muscles.

Fracture healing in HIV-positive populations

Highly active anti-retroviral therapy has transformed HIV into a chronic disease with a long-term asymptomatic phase. As a result, emphasis is shifting to other effects of the virus, aside from immunosuppression and mortality. We have reviewed the current evidence for an association between HIV infection and poor fracture healing. The increased prevalence of osteoporosis and fragility fractures in HIV patients is well recognised. The suggestion that this may be purely as a result of highly active anti-retroviral therapy has been largely rejected. Apart from directly impeding cellular function in bone remodelling, HIV infection is known to cause derangement in the levels of those cytokines involved in fracture healing (particularly tumour necrosis factor-alpha) and appears to impair the blood supply of bone. Many other factors complicate this issue, including a reduced body mass index, suboptimal nutrition, the effects of anti-retroviral drugs and the avoidance of operative intervention because of high rates of wound infection. However, there are sound molecular and biochemical hypotheses for a direct relationship between HIV infection and impaired fracture healing, and the rewards for further knowledge in this area are extensive in terms of optimised fracture management, reduced patient morbidity and educated resource allocation. Further investigation in this area is overdue.

Rehabilitation control strategies for a gait robot via EMG evaluation

Therapists often emphasize selection and design of proper training programs for individual patients in different situations and rehabilitation stages. Thus, in order to cater different patient groups, this paper proposes four assistant control strategies for robotic rehabilitation of gait locomotion: (1) orthosis-free, (2) totally-passive, (3) optimal assistance and (4) resistance exercise. A robotic gait system with pelvic control (PC) is also designed by integrating body weight support (BWS), robotic orthosis (RO), parallelogram arm (PA), and mobile platform (MP). This paper also investigates the electromyography (EMG) signals from the eight major muscles of the leg and compares them to those created by our robotic device. The initial results of clinical trials indicate the potential for robotic rehabilitation in patients with gait impairments.

The outcome of spinal decompression surgery 5 years on

Decompression surgery is an increasingly common operation for the treatment of lumbar spinal stenosis. Although good relief from leg pain is expected after surgery, long term results of pain relief and function are more uncertain. This study prospectively followed a cohort of patients presenting with the signs and symptoms of spinal stenosis, who underwent decompression surgery to ascertain the long term outcome with respect to pain and function using visual analogue pain scores, the Oswestry Disability Index, and the Short Form 36, a general health questionnaire. From an initial pool of 84 recruited patients, 7 withdrew from surgical intervention; of the remaining 77, 51 (66%) returned for follow up assessments at 5xa0years. In these responders, a significant improvement was observed in back and leg pain, which was sustained for at least 1xa0year (Pxa0<xa00.01). A significant improvement was also seen in physical function (Pxa0<xa00.05) as assessed by Oswestry and SF-36. Although an initial improvement was noted in social function, this was not observed at 5xa0years. This study has demonstrated that decompression surgery is successful in relieving symptoms of lumbar spinal stenosis. Physical function, back and leg pain are significantly improved after 5xa0years but initial significant improvements in social function diminish over time.

Do men and women row differently? a spinal kinematic and force perspective

Performance differences have been noted between male and female rowers; the aim of this study was to determine if these are due to differences in rowing technique. An electromagnetic motion measurement device in conjunction with a load cell was used to compare the ergometer rowing kinematics of female and male elite national rowers. Male rowers generated significantly greater peak force during the stroke, (p < 0.0001) and greater power. Although there was no difference in stroke length, females demonstrated a more optimal lumbopelvic rhythm due to a greater anterior pelvic rotation during the stroke (p < 0.05). This is likely to account for the lack of difference in stroke length. In conclusion, gender differences do exist in kinematic parameters of rowing technique. With a greater mass and height, the male athletes are more powerful than the females; however, females appear to optimize their kinematics in an attempt to enhance performance.

Trunk muscle responses following unpredictable loading of an abducted arm.

This study investigated if asymmetry exists in the responses of trunk muscles to a perturbation of the trunk induced by loading of an outstretched arm. Nineteen healthy right-handed subjects were recruited into the study. Electromyographic recordings were made from trunk muscles (erector spinae and rectus abdominus) and upper limb muscles (deltoid). A weight was dropped into a receptacle held out laterally by the subjects. The perturbation induced a rise in EMG activity in the deltoid at a latency which was not different between the dominant and non-dominant arms. It also induced a rise in EMG activity in the contralateral trunk muscles. Although not significantly different, there was a trend for the responses from the right trunk to be longer than those from the left trunk. Furthermore, there were higher levels of EMG activity in the trunk muscles opposite the dominant arm than those in the trunk muscles opposite the non-dominant arm. This study reveals a pattern of trunk muscle activation following movement in the arm induced by loading of an outstretched hand that is different on the side of the back opposite the dominant arm than on the side of the back opposite the non-dominant arm. These results may have implications in terms of mechanisms contributing to low back pain and further work is warranted to examine these responses in left-handed individuals.

Modulation of weight off-loading level over body-weight supported locomotion training

With the evolution of robotic systems to facilitate overground walking rehabilitation, it is important to understand the effect of robotic-aided body-weight supported loading on lower limb muscle activity, if we are to optimize neuromotor recovery. To achieve this objective, we have collected and studied electromyography (EMG) data from key muscles in the lower extremity from healthy subjects walking over a wide range of body-weight off-loading levels as provided by a bespoke gait robot. By examining the impact of body-weight off-loading, it was found that muscle activation patterns were sensitive to the level of off-loading. In addition, a large off-loading might introduce disturbance of muscle activation pattern, led to a wider range of motion in terms of dorsiflexion/plantarflexion. Therefore, any future overground training machine should be enhanced to exclude unnecessary effect of body off-loading in securing the sustaining upright posture and providing assist-as-needed BWS over gait rehabilitation.