No description available.

Dynamic surface topography is a method to quantify the surface and locations of features acquired from moving and distorting shapes against time. This thesis describes the application of the technique to the potential evaluation of adolescent idiopathic scoliosis patients. Scoliosis or curvature of the spine is one of the major skeletal diseases in adolescents where in the majority of cases the cause is unknown or idiopathic. The progression of the disease occurs in three dimensions with the spine simultaneously curving towards the arms and rotating as it collapses with the first indications usually being changes in body symmetry and back surface shape. Following diagnosis, most children do not exhibit any significant worsening of their condition and are routinely monitored using radiography as frequently as every three months whilst vertebral growth potential remains. In a small number of patients, the lateral curvature can unpredictably worsen requiring, in some cases, surgical intervention to prevent further deterioration and to diminish the deformity. Earlier work by many researchers concentrated on attempting to reduce patient exposure to ionizing radiation by investigating if there was a reliable correlation between progression of the scoliosis and changes in surface topography. The techniques have not gained acceptance as the relational algorithms were found to be insufficiently robust in all cases and measurements acquired from available technologies were prone to artefacts introduced by stance, breathing, 'posture and sway. For many patients the motivation in seeking treatment is for the improvement of their appearance rather than to correct the underlying deformity, so cosmetic concerns and an understanding of the psychosocial and physical impacts of the disease and treatments remain important factors in the clinical decision-making process. In the current environment of evidence based medicine there is a growing need to quantify back surface shape, general body asymmetry and patient capability with the objective of producing an agreed scoring to be used in developing treatment plans and assessing outcomes but to date many clinics continue to rely on qualitative methods to describe cosmetic deformity and ability. The aim of the research was to develop an original, low cost and inherently safe apparatus using well understood video based motion capture technology that overcame the disadvantages of earlier work by simultaneously acquiring multiple samples of back surface shape and the locations of bony landmarks to provide averaged results for a quantitative and reliable analysis of cosmetic defect and physical impairment. 172,650 data samples were acquired from thirty skeletally mature subjects not exhibiting any musculoskeletal disease to define normality limits for Page 2 established morphological measurements and to compare the specificity of the approach with existing single sample techniques. Three novel calculations of back paraspinous volumetric asymmetry were tested of which two were found to be potentially useful clinical indicators of deformity and an index was proposed and tested using simulated data that could offer a single value to describe patient back shape asymmetry. Previous research has found that there is a loss of trunk ranges of motion among postoperative patients that has a direct impact on their quality of life, function and physical capability. Data were acquired from the mature subjects and similar results were observed when compared with published data for preoperative scoliosis patients. This thesis has shown that using averaged tri-dimensional morphological and back shape data combined with measurement of dynamic capability acquired using an inherently safe apparatus have the potential to be clinically useful. The opportunity to routinely and safely quantify the cosmetic defect and trunk ranges of motion of adolescent idiopathic scoliosis patients should stimulate more important research to help improve the quality of life of many affected children throughout the world.

Introduction: The aims of the current investigations were to modulate muscle-tendon complex (MTC - vastus lateralis [VL] & patella tendon [PT]) adaptations through mechanical stress and strain. Groups performed resistance training (8 weeks) with the MTC placed in a shortened (SL) or a lengthened position (LL) with internal loading standardised. A third group trained over an entire ROM (LX) with the external loading matched to that in SL. MTC response to detraining (4 weeks) was also measured. A control, untrained group was measured during this 12-week period. Methods: Measurements using ultrasonography, dynamometry, electromyography and dual energy absorptiometry were made at baseline (week 0), post-training (week 8), detraining 1 (week 10) and detaining 2 (week 12). VL measurements included volume, cross-sectional area (CSA), and architecture. PT properties included stiffness and Young’s Modulus. Quadriceps MTC function was measured by isometric maximal voluntary contractions (MVC) over a range of joint –angles. Circulating levels of a growth factor (IGF-I) and cytokines (TGF-β1, TNF-α) were measured using enzyme-linked immuno-sorbant assay. Main Results: VL volume, CSA, fascicle length, PT stiffness, modulus, quadriceps MVCs and IGF-I (LL only) were significantly greater (p<0.05) in both LL and LX groups compared to SL post-training. During detraining, CSA, fascicle length, stiffness, modulus, IGF-I (LL only) remained significantly elevated in the LL and LX groups compared to SL. There was no significant change in the control group in any measurement during the study period (p>0.05). Conclusion: Training with the MTC in a lengthened position is more effective for inducing (and retaining) enhanced training MTC adaptations, owing to internal mechanical and physiological stress in this position. This loading method should therefore be incorporated into a structured resistance training program for a range of populations such as athletic, recreationally active, clinical or elderly individuals.

Introduction: Exercise-induced muscle damage (EIMD) is an accepted consequence of eccentric exercise. Sex differences in EIMD are attributed to tendon properties, fascicle lengthening and direct hormonal influences, however these remain unreported in vivo. Furthermore, the classical definition of eccentric contractions omits the role of the elastic tendon in determining eccentric fascicle lengthening and subsequent EIMD. Aim: The overall aims of the current thesis were, to investigate the role of the patella tendon during eccentric contractions, to investigate whether muscle and tendon properties are determinants of EIMD and investigate group differences (sex and oral contraceptive (OCP)use) in EIMD. Materials and method: In brief, vastus lateralis (VL) and patella tendon properties were measured in males, females and female OCP users, using a combination of ultrasonography, electromyography and dynamometry. During maximal voluntary eccentric knee extensions ((MVEKE) 12 reps × 6 sets), VL fascicle lengthening and MVEKE torque was recorded every 10 of knee joint angle (20 - 90). Maximal isometric voluntary knee extensor (MVCKE) torque loss, creatine kinase (CK) and muscle soreness were measured pre, post, 48, 96 and 168 hours post damage as markers of EIMD. Main findings: Patella tendon properties appear to act as a mechanical buffer on VL fascicle lengthening during MVEKE in vivo. Furthermore, due to significantly higher patella tendon stiffness, VL fascicle lengthening was significantly greater in males compared to females. Despite evidencing an attenuating role of the patella tendon on VL fascicle lengthening, patella tendon properties did not correlate with any indirect markers of EIMD, nor did they explain group differences in EIMD. Furthermore, MVEKE torque, MVEKE torque made relative to estimated total quadriceps anatomical cross-sectional area and VL fascicle lengthening did not correlate with any functional indirect marker of EIMD, nor did they explain group differences in EIMD. Within the current thesis CK was the only indirect marker of EIMD to be significantly different between the groups (males > females < OCP users). Creatine kinase was consistently lower in the groups with lower circulating oestrogen levels. Therefore, it was concluded that the antioxidant and membrane stabilising role of oestrogen might explain the group differences in CK reported in the current thesis. Conclusion: In agreement with the historical definition, VL fascicles lengthen during MVEKE. Furthermore, it is evident from the current thesis that patella tendon properties determine the magnitude of VL fascicle lengthening during MVEKE, but do not appear to explain the variability or group differences in EIMD.

It has previously been established that individuals with mild chronic low back pain (CLBP) have a delayed rate of post-exercise stature recovery compared to asymptomatic controls, and that this is associated with increased paraspinal muscle activity, pain and disability. The purpose of this thesis was to explore these relationships further in NHS patients with CLBP and to establish if links exist between these measures and a number of psychological factors known to play an important role in the development of the condition. Forty seven patients were recruited from the waiting list for two physiotherapist-led rehabilitation programmes. Paraspinal muscle activity was assessed via surface EMG while standing at rest and stature recovery over a 40-minute unloading period was measured on a precision stadiometer. Self-report of pain was noted and patients were asked to complete a questionnaire booklet assessing disability, anxiety, depression, pain-related anxiety, fear of movement, self-efficacy, catastrophising and defensiveness. Where possible, patients returned for a second testing session after completing the rehabilitation programme (n = 23) and again after a further six months (n = 14). The effect of superficial heat treatment was additionally assessed via a similar testing session (n = 24), but on this occasion the participant put on a heat wrap two hours before the time of the appointment. Significant correlations were found between baseline muscle activity and both pain and disability. Pain was a significant mediator in the relationship between muscle activity and disability. Muscle activity also demonstrated links with self-efficacy, depression, anxiety, pain-related anxiety and catastrophising and was a significant mediator in the relationship between self-efficacy and pain. Stature recovery was not significantly related to any of the other baseline measures, perhaps reflecting the heterogeneous nature of the patients involved. A high prevalence of defensive high anxious individuals was found in the patient group. Changes in stature recovery immediately following the programme were significantly linked to improvements in pain and disability, although a significant increase in stature recovery was only observed by the end of the follow-up period. Resting EMG was not reduced following the rehabilitation programme. The heat wrap resulted in a significant decrease in non-normalised EMG levels and a positive effect on self-report of disability, self-efficacy, catastrophising and pain-related anxiety. In conclusion, the relationship between stature change and muscle activity appears to be more complex than originally hypothesized. However, six months after a rehabilitation programme, the rate of stature recovery had increased to levels similar to asymptomatic individuals, suggesting that the delayed recovery seen in CLBP patients is not primarily the result of pathology. The findings confirm that muscle activity plays an important role in CLBP, in particular as a pathway by which psychological factors may impact on clinical outcome. The role of muscle activity as a mediator between psychological factors and pain suggests that interventions that are able to reduce muscle activity may be of particular benefit to patients demonstrating characteristics such as low self-efficacy, which may help in the targeting of treatment for CLBP. The results also highlight that an immediate decrease in EMG levels following active treatment may not always be the optimal response for long-term improvements in clinical outcome and that a period of adaptation might be expected. The unexpectedly high prevalence of a defensive high anxious coping style suggests that this may represent a risk factor for CLBP, a predictor of poor outcome or an adaptation to a chronic condition.

No description available.

Rheumatoid arthritis (RA) is a chronic, progressive and systemic auto-immune disease. However, there is very little research on how patients experience daily symptoms and their impact on life, nor how patients self-manage their symptoms on current treatment regimes. Flares of RA lead to major drug treatment decisions, yet there is no standardised definition of flare to support these decisions. Further, there is a dearth of literature addressing the decision-making process surrounding flare help-seeking. A mixed methods, pragmatic approach was taken to address these issues, employed iteratively in three studies: semi-structured interviews, Q-methodology and a longitudinal survey of daily symptoms for three months, alongside self-management and flare help-seeking. The interviews identified that even on current aggressive medication, in daily life patients experience continuing symptoms that vary within and between patients, and can be significant. When discussing their RA, patients used metaphors to enhance their explanations of inexplicable phenomena, such as flare. They fluctuate between living with their RA in the background, moving into the foreground, and at times having to deal with RA in the foreground. Each day patients attempt to balance the physical and emotional impact of RA with independence, a sense of normality and identity, by employing a stepped approach to self-management (“Mediation Ladder”), which leads to a life of Fluctuating Balances. When self-management is difficult, the Fluctuating Balances Model tips and their RA shifts into the foreground. The interview themes informed the two Q-methodology studies, which demonstrated four different experiences of daily life: “Feeling Good”, “Taking Active Control”, “Keeping RA in its Place” and “Struggling Through” (reported predominantly by men) and two ways in which patients differed in their decision-making process for seeking medical help for an RA flare: “Definite Decision” and “Cautious Indecision”. Items ranked as important were used to inform the survey studies, which identified that patients do not necessarily experience their highest symptoms when they are in flare. Thus two different flare-types have been identified: “Inflammatory Flare” (defined by pain and inflammation) and “Avalanche Flare” (defined by the cascading effect of inflammatory symptoms, emotions and life events). Patients are prompted to seek help when the impact of the flare becomes unmanageable. These findings have implications for clinical practice. First, the improved understanding of daily life with RA can be used to talk realistically with new patients about levels of symptoms and the Fluctuating Balances of daily life. Second, there is a need for agreed terminology between patients and professionals to define flare. Third, clinicians need to be aware that men are “struggling through” with their RA. Fourth, using or responding to metaphors may facilitate communication between patients and professionals. Future research needs to develop a greater understanding of men’s experiences of RA and support needs; to design an outcome measure for the novel concept of “Avalanche Flare”; and a fully-powered study to identify daily symptom patterns and potentially predict future symptom/flare patterns that might inform treatment decisions.

Previous work on the acute compartment syndrome has concentrated on its effect on the soft tissues. A retrospective study demonstrated an increased likelihood of delayed union in tibial diaphyseal fractures complicated by acute compartment syndrome and its was suggested that this could be due to an effect on the bone blood flow. Bone blood flow using microspheres, bone union histologically and the strength of bone healing with biomechanical testing were examined in a series of New Zealand white rabbits after tibial osteotomy with or without an induced acute compartment syndrome. Six weeks after osteotomy bone blood flow is significantly elevated in the group with acute compartment syndrome while the tibial blood flow in the control group has returned to normal indicating a delay in the normal progression of the recovery of bone blood flow after osteotomy. This is reflected in the biomechanical testing which demonstrated significantly weaker bone union at six weeks in the compartment syndrome group. Histologically at this stage the callus in the experimental group is less mature than in the control groups. In the clinical study data was collected on 68 patients with acute compartment syndromes. Tibial diaphyseal fractures with clinical evidence of muscle necrosis took more than twice as long to unite as those without complications and delay to fasciotomy also caused a significant increase in union times. The clinical study also examined the use of compartment pressure monitoring and validated the use of a P measurement (diastolic pressure minus compartment pressure) of less than 30mm Hg as a threshold for decompression. Continuous compartment monitoring was shown to have a highly significant influence on the reduction of complications after acute compartment syndrome.

The two most important elements in the clinical management of long bone fractures are generally considered to be the state of the vascular supply to the bone fragments and the requirement for mechanical stability. The contribution of each of these factors has been extensively studied independently, but their relative significance in the early phase of the healing process remains poorly defined. Recent evidence that intermittent micromovement at the fracture site may enhance the rate of union under experimental conditions has yet to be effectively demonstrated in clinical practice, particularly in high velocity injuries where bony comminution and soft tissue damage may be prominent. The objective of this thesis was to quantify the role of the vascular response to different mechanical environments, with and without suppression of musculoperiosteal collateral blood flow, after a transverse two-millimetre osteotomy of the ovine tibia which was held in an instrumented external fixation device. Three groups of skeletally mature three year old female Scottish blackface sheep were used for the study. In the well-vascularised groups the axial fixation stiffness was 460 N/mm and 240 N/mm respectively; in the devascularised group it was 240 n/mm and after subperiosteal exposure, a silicone rubber sleeve was interposed circumferentially between cortex and muscle. Outcome was assessed by in vivo measurement of fixator axial load and group reaction force, calculation of axial interfragmentary gap strain and external counting of dynamic uptake of Technetium-99m methylene diphosphonate at the osteotomy site. Regional blood flow was determined using the radioactive tracer microsphere technique at 14 and 42 days after osteotomy. Post-mortem, the isolated tibiae were mechanically tested in torsion and cross sections taken adjacent to the interfragmentary zone, from which area, perimeter, porosity and mineral apposition rate in cortex and callus were calculated.

In these studies, the primary afferent neuronal response to peripheral inflammation with respect to neuropeptide mRNA expression, and the role of the primary afferent and its neuropeptides in the spread of arthritis have been examined. The regulation of neuropeptide genes in DRG during inflammation is not well understood. Blockage of the increase in primary afferent spontaneous activity known to be observed within hours of the onset of inflammation using local anaesthetic prevented the increase in PPT and CGRP mRNA seen in DRG 8 hours after adjuvant injection. While endogenous glucocorticoids have been shown to regulate neuropeptide levels in DRG, adrenalectomy had no effect on the degree or spread of arthritis and had only subtle effects on the expression of PPT and CGRP mRNA. Expression of transcription factors in DRG on noxious stimulation has not been demonstrated, and this has been substantiated in these experiments as expression of NGFI-A, NGFI-B and c-jun was not detectable in DRG innervating inflamed or uninflamed joints. AP-2 mRNA, encoding a transcription factor constitutively expressed in tissue of neural crest origin, showed a rapid increase in expression one hour after injection, returning to control levels within 2 hours. The possible involvement of AP-2 in the regulation of these neuropeptides remains to be determined. In conclusion, these data support the hypothesis that polymodal nociceptors and the neuropeptides they express are closely associated with the maintenance and spread of arthritis. Changes in neuropeptide mRNA expression may be regulated through many mechanisms, including neuronal activity, and transcription factor induction.