During ambulation, lower-extremity joint angles and net moments influence knee joint load. It is unclear which mechanical variables most strongly correlate with acute articular cartilage (AC) catabolism in response to ambulation. Purpose: To determine which mechanical variables are most strongly correlated to acute AC catabolism, and to test the acute effect of ambulation speed on AC catabolism, while controlling for load frequency. Methods: 18 able-bodied subjects (9 male, 9 female; age = 23 ± 2 y; mass = 68.3 ± 9.6 kg; height = 1.70 ± 0.08 m) completed three separate ambulation sessions: slow (preferred walking speed), medium (+50% of walking speed), and fast (+100% of walking speed). For each session, subjects completed 4000 steps on an instrumented treadmill while ten high-speed cameras recorded synchronized video data. Various, discrete, three-dimensional joint kinematic and kinetic variables were averaged across 20 total stance phases (5 stance phases at 1000, 2000, 3000, and 4000 steps). Blood samples were collected pre-, post-, 30-min post-, and 60-min post-ambulation. Serum cartilage oligomeric matrix protein (COMP) concentration was determined using an enzyme-linked immunosorbent assay. A stepwise multiple linear regression analysis was used to evaluate the relationships between serum COMP change and lower-extremity joint angles and moments. A mixed model ANCOVA was used to evaluate serum COMP concentration between sessions across time. Results: Peak ankle inversion, knee extension, knee abduction, hip flexion, hip extension, and hip abduction moment, and knee flexion angle at impact, explained 61.4% of the total variance in serum COMP change (p < 0.001), due to ambulation. COMP concentration increased 28%, 18%, and 5% immediately after ambulation for the running, jogging, and walking sessions, respectively. All sessions were significantly different immediately post-ambulation (p < 0.01). Conclusion: Certain lower-extremity joint mechanics are associated with acute AC catabolism, due to ambulation. Several key mechanical variables (e.g., peak knee extension, knee abduction, and hip abduction moments) explain much regarding the variance in serum COMP increase. These lower-extremity variables can be used to predict acute AC catabolism, allowing researchers and clinicians to better predict and/or understand AC catabolism. Additionally, when load frequency is controlled, increased ambulation speed acutely results in increased AC catabolism. Ambulation speed does not, however, influence serum COMP elevation duration. Joint mechanics and load frequency appear to be responsible for the magnitude of COMP increase, while duration of COMP elevation post-ambulation is dictated by load frequency.

Thesis (Ph. D.)--University of Missouri--Columbia, 1998. / "May 1998." Typescript. Vita. Includes bibliographical references (leaves 104-107). Also available on the Internet.

The ability to successfully negotiate stairs and steps is an important factor for functional independence. While work has been undertaken to understand the biomechanics of gait in lower-limb amputees, little is known about how amputees negotiate stairs and steps. This study aimed to determine the mechanics of landing in unilateral lower-limb amputees when stepping down to a new level. A secondary aim was to assess the effects of using a shank-mounted shock-absorbing device (Tele-Torsion Pylon) on the mechanics of landing. Methods Ten unilateral amputees (five transfemoral and five transtibial) and eight able-bodied controls performed single steps down to a new level (73 and 219 mm). Trials were repeated in amputees with the Tele-Torsion Pylon active and inactive. The mechanics of landing were evaluated by analysing peak limb longitudinal force, maximal limb shortening, lower extremity stiffness, and knee joint angular displacement during the initial contact period, and limb and ankle angle at the instant of ground-contact. Data were collected using a Vicon 3D motion analysis system and two force platforms. Findings Amputees landed on a straightened and near vertical limb. This limb position was maintained in transfemoral amputees, whereas in transtibial amputees knee flexion occurred. As a result lower extremity stiffness was significantly greater in transfemoral amputees compared to transtibial amputees and able-bodied controls (P < 0.001). The Tele-Torsion Pylon had little effect on the mechanics of landing in transtibial amputees, but brought about a reduction in lower extremity stiffness in transfemoral amputees (P < 0.05). Interpretation Amputees used a stepping strategy that ensured the direction of the ground reaction force vector was kept anterior of the knee joint centre. Using a Tele-Torsion Pylon may improve the mechanics of landing during downward stepping in transfemoral amputees.

The purpose of this study was to determine the effects of cessation of a 12-month thrice-weekly body-weight supported treadmill training (BWSTT) program on functional ambulation and aspects of health-related quality of life (HRQL) in individuals with incomplete SCI. Twelve men and women (aged 22-55) with chronic (> 1 year post-injury) incomplete SCI (ASIA B or C) returned for follow-up (FOL) testing 37 weeks (SD 2.1) following their final scheduled BWSTT session. Functional ambulation was compared based on: i) required percentage of body-weight support (%BWS) on the treadmill, ii) preferred treadmill speed and iii) overground walking. Evaluation of HRQL included measures of: i) satisfaction with life, ii) perceived ability to perform activities of daily living (ADL), iii) perceptions of health, and iv) depressive symptomology. Participants were invited to participate in once-weekly BWSTT and twice-weekly fitness training during the FOL period (37 sessions); the actual number of BWSTT sessions attended was only 11.6 (range 0-29) and the total days of exercise was 29.1 (range 0-75). The 12-month BWSTT program resulted in a decrease in the required %BWS (73±10% to 19±12%; p<.01), an increase in treadmill speed (0.5±0.3 to 1.4±0.8 km/h; p<.01), improved overground walking in 4 individuals, and improved group satisfaction with life (p<.05). At FOL, %BWS increased to 35±14% (p<.01), but was still less than at pre-training (p<.01). There were no differences between 12-month and FOL scores on any HRQL-related measures. High exercise adherence during the FOL period had a strong correlation with a positive percent change in perceived ability to perform ADL (r = .70; p<.05), as well as non-significant trends with positive percent change in perceptions of health and negative percent change in depressive symptomology (r = .49; p=.13 and r = .51; p=.ll, respectively). Therefore, even with very limited access to the BWS treadmill, much of the improvement in treadmill walking ability and satisfaction with life following long-term BWSTT in individuals with incomplete SCI can be retained for at least 8 months. Continued exercise participation, however, may contribute to maintain or further improve aspects of HRQL in this population. / Thesis / Master of Science (MS)

Purpose: To determine the timing of first ambulation during hospitalization among patients admitted for acute myocardial infarction (AMI) and to identify the predictors of first ambulation. Methods: This retrospective cohort study included 500 AMI patients admitted during 2004 to one of three hospitals that form the Hamilton Health Sciences Corporation in Hamilton, Ontario, Canada. The patients were randomly selected from a total of 1,014 charts from the Hamilton Health Sciences Computerized Health Records (SOVERA). Using a chart abstraction tool, the following data were collected from each patient's chart: demographic information, past medical history, treatment, complications, and patterns of ambulation while in hospital. The primary outcome was first ambulation, defined as the first time patients walked during their hospital stay. Secondary outcomes included heart rate at discharge and mortality during hospitalization. The relationship between patient and care-related factors and the time of first ambulation after AMI was explored through a time to event analysis using Cox regression; the associations were expressed as hazard ratios. The fit for the proportional hazard model was assessed and a stratified proportional hazard model was performed for age. Results: Of the 500 charts, 60 were excluded. Of the 440 patients who were included in the final analysis, 340 (77.3%) walked during hospitalization. One hundred fifteen (26.1 %) walked during the first 48 hours (early walking), 98 (22.3%) walked between 49-96 hours (intermediate walking), and 127 (28.9%) walked after 96 hours (late walking). A total of 100 patients (22.7%) were categorized as non-walkers. Factors that emerged in the survival analysis that were positively associated with early ambulation after AMI and that proved the proportionality on the assessment of the fit of the model were: having a family history of cardiovascular disease (HR 1.33; 95% Cl 1.00, 1.44; p=0.05), receiving thrombolysis (HR 1.47; 95% Cl 1.11, 1.49; p=0.007), receiving nitroglycerin (HR 1.51; 95% Cl 1.19, 1.93; p<0.001 ), and taking calcium channel blockers (HR 1.58; 95% Cl 1.22, 2.05; p<0.001 ). Factors that were negatively associated with early ambulation after AMI were age >59 years (HR 0.98; 95% Cl 0.97, 0.99; p<0.001 ), having an arrhythmia in-hospital (HR 0.48; 95% Cl 0.22, 0.94; p=0.04), taking inotropic drugs (HR 0.72; 95% Cl 0.53, 0.98; p<0.001 ), and undergoing coronary artery bypass surgery (HR 0.51; 95% Cl 0.33, 0.78; p=0.002). Conclusion: There is variability in the timing of first ambulation among patients hospitalized with an AMI. Furthermore, those who walked early were more likely to have a family history of cardiovascular disease, have received thrombolysis, and be taking nitroglycerin or calcium channel blockers. Those least likely to walk early were older (>59 years), were more likely to have had an arrhythmia inhospital, to be taking inotropic drugs, and to have undergone coronary artery bypass surgery. / Thesis / Doctor of Philosophy (PhD)

Objetivos: O objetivo do presente estudo foi avaliar o efeito de um programa pósoperatório de mobilização precoce na capacidade funcional e na incidência de complicações clínicas em pacientes submetidos à cirurgia oncológica abdominal de grande porte, quando comparado a uma estratégia de reabilitação pósoperatória convencional. Desenho: Estudo fase III de superioridade, unicêntrico, randomizado e controlado. Local: Unidades de internação (enfermarias e Unidade de Terapia Intensiva) do Instituto do Câncer do Estado de São Paulo, Faculdade de Medicina da Universidade de São Paulo, Brasil. Participantes: Pacientes adultos do Instituto do Câncer do Estado de São Paulo, submetidos à cirurgia oncológica abdominal de grande porte. Intervenção: Após assinarem o termo de consentimento livre e esclarecido e antes do procedimento cirúrgico, os pacientes foram aleatoriamente alocados para um protocolo de mobilização precoce pós-operatório, supervisionado, com treino aeróbico e resistido, que seguia um protocolo de progressão específico, realizado 2x/dia ou para um grupo controle, sem treino aeróbico e resistido específico, realizado 1x/dia. Desfecho primário: Inabilidade para atravessar o quarto do hospital ou andar três metros, sem ajuda de terceiros, na ocasião do 5° dia de pós-operatório. Resultados: Foram incluídos 108 pacientes na análise final; destes, 54 foram alocados no grupo intervenção e 54 no grupo controle. O desfecho primário ocorreu em 16,7% (95% Intervalo de confiança [IC] 7,9 - 29,3) dos pacientes do grupo submetido ao protocolo de mobilização precoce e em 38,9% (95% IC 25,9 - 53,1) dos pacientes do grupo controle (p= 0,010). Comparado com a reabilitação convencional, o protocolo de mobilização precoce no pós-operatório resultou em redução do risco absoluto do desfecho primário em 22,2% (95% IC 5,9 - 38,6) e um número necessário para tratar de 4,5 (95% IC 2,5 - 17,1). Conclusões: Um programa de mobilização precoce pós-operatório resultou em redução da perda funcional em pacientes submetidos à cirurgia oncológica abdominal de grande porte para tratamento do câncer quando comparado a um programa de reabilitação pós-operatória convencional / Objectives: The aim of this study was to evaluate the effect of early mobilization program performed in the postoperative in the functional capacity and incidence of clinical complications in patients undergoing major elective oncologic abdominal surgery. Design: Phase III, randomised, unicentric, controlled, parallel-group, superiority trial. Setting: Regular ward and Intensive Care Unit of Instituto do Cancer do Estado de São Paulo, Faculdade de Medicina da Universidade de São Paulo, a tertiary oncology university hospital in Sao Paulo, Brazil. Participants: Adult patients with cancer who underwent major abdominal oncologic surgery were included. Interventions: After signing informed consent and before surgery, patients were randomly assigned to a group of early postoperative mobilization program, with a specific aerobic and resistance training twice a day or to a control group (standard rehabilitation care, once a day). Main outcome measure: Inability to cross the room or walk 3 meters without human assistance, at 5th postoperative day. Results: A total of 108 patients were included in the final analysis. Fifty four were randomized to the intervention group and 54 to standard group. The primary endpoint occurred in 16.7% (95% confidence interval [CI] 7,9 - 29,3) of patients in the intervention group and in 38.9% (95%CI 25,9 - 53,1) of patients in the standard group (p=.010). Compared to the standard group, the early mobilization program in postoperative resulted in an absolute risk reduction for the outcome of 22.2% (95%CI 5.9 - 38.6) and a number needed to treat of 4.5 (95%CI 2.5 - 17.1). Conclusions: An early mobilization program resulted in greater postoperative functional capacity in patients undergoing major cancer surgery compared with a standard rehabilitation Trial registration: NCT01693172

Objetivos: O objetivo do presente estudo foi avaliar o efeito de um programa pósoperatório de mobilização precoce na capacidade funcional e na incidência de complicações clínicas em pacientes submetidos à cirurgia oncológica abdominal de grande porte, quando comparado a uma estratégia de reabilitação pósoperatória convencional. Desenho: Estudo fase III de superioridade, unicêntrico, randomizado e controlado. Local: Unidades de internação (enfermarias e Unidade de Terapia Intensiva) do Instituto do Câncer do Estado de São Paulo, Faculdade de Medicina da Universidade de São Paulo, Brasil. Participantes: Pacientes adultos do Instituto do Câncer do Estado de São Paulo, submetidos à cirurgia oncológica abdominal de grande porte. Intervenção: Após assinarem o termo de consentimento livre e esclarecido e antes do procedimento cirúrgico, os pacientes foram aleatoriamente alocados para um protocolo de mobilização precoce pós-operatório, supervisionado, com treino aeróbico e resistido, que seguia um protocolo de progressão específico, realizado 2x/dia ou para um grupo controle, sem treino aeróbico e resistido específico, realizado 1x/dia. Desfecho primário: Inabilidade para atravessar o quarto do hospital ou andar três metros, sem ajuda de terceiros, na ocasião do 5° dia de pós-operatório. Resultados: Foram incluídos 108 pacientes na análise final; destes, 54 foram alocados no grupo intervenção e 54 no grupo controle. O desfecho primário ocorreu em 16,7% (95% Intervalo de confiança [IC] 7,9 - 29,3) dos pacientes do grupo submetido ao protocolo de mobilização precoce e em 38,9% (95% IC 25,9 - 53,1) dos pacientes do grupo controle (p= 0,010). Comparado com a reabilitação convencional, o protocolo de mobilização precoce no pós-operatório resultou em redução do risco absoluto do desfecho primário em 22,2% (95% IC 5,9 - 38,6) e um número necessário para tratar de 4,5 (95% IC 2,5 - 17,1). Conclusões: Um programa de mobilização precoce pós-operatório resultou em redução da perda funcional em pacientes submetidos à cirurgia oncológica abdominal de grande porte para tratamento do câncer quando comparado a um programa de reabilitação pós-operatória convencional / Objectives: The aim of this study was to evaluate the effect of early mobilization program performed in the postoperative in the functional capacity and incidence of clinical complications in patients undergoing major elective oncologic abdominal surgery. Design: Phase III, randomised, unicentric, controlled, parallel-group, superiority trial. Setting: Regular ward and Intensive Care Unit of Instituto do Cancer do Estado de São Paulo, Faculdade de Medicina da Universidade de São Paulo, a tertiary oncology university hospital in Sao Paulo, Brazil. Participants: Adult patients with cancer who underwent major abdominal oncologic surgery were included. Interventions: After signing informed consent and before surgery, patients were randomly assigned to a group of early postoperative mobilization program, with a specific aerobic and resistance training twice a day or to a control group (standard rehabilitation care, once a day). Main outcome measure: Inability to cross the room or walk 3 meters without human assistance, at 5th postoperative day. Results: A total of 108 patients were included in the final analysis. Fifty four were randomized to the intervention group and 54 to standard group. The primary endpoint occurred in 16.7% (95% confidence interval [CI] 7,9 - 29,3) of patients in the intervention group and in 38.9% (95%CI 25,9 - 53,1) of patients in the standard group (p=.010). Compared to the standard group, the early mobilization program in postoperative resulted in an absolute risk reduction for the outcome of 22.2% (95%CI 5.9 - 38.6) and a number needed to treat of 4.5 (95%CI 2.5 - 17.1). Conclusions: An early mobilization program resulted in greater postoperative functional capacity in patients undergoing major cancer surgery compared with a standard rehabilitation Trial registration: NCT01693172

The purpose of this dissertation was to explore the physical and psychological responses to the combination of major trauma (Injury Severity Score [ISS] > 15) and variable periods of immobility. Specific aims were to: 1) develop a conceptual model that illustrates physiological and psychological alterations that occur after injury and subsequent immobility, and their association with skeletal muscle responses and recovery; 2) evaluate daily measures of skeletal muscle strength (bicep and quadricep) using dynamometry and skeletal muscle (rectus femoris and biceps brachii) muscle thickness measured with ultrasound in patients after major trauma; and 3) assess the predictive ability of anxiety and depressive symptoms after traumatic injury on delayed ambulation (> 48 hours) following hospital admission. Specific Aim 1 was addressed by development of a conceptual model to describe the association between injury responses, immobility and skeletal muscle after trauma based on a comprehensive review of the state of the science. This model guided the research reported in Aims 2 and 3. The second specific aim was addressed with the conduct of an observational study in which we evaluated daily skeletal muscle strength with dynamometry and muscle thickness with ultrasound to evaluate the impact of trauma and immobility on skeletal muscle in patients after major trauma (n = 19). Participants with delayed ambulation after trauma (more than 48 hours immobility) demonstrated significantly less muscle strength compared with those who had early ambulation (bicep: delayed ambulation 12.9 ± 3.8, early ambulation 17.7 ± 4.7, p = 0.004; quadriceps: delayed ambulation 9.9 ± 3.1, early ambulation 17.1 ± 4.6, p = 0.001). Muscle thickness was unchanged over time in those with delayed ambulation; however, in those who ambulated early, muscle thickness significantly increased by 0.17 cm (p = 0.008) from baseline to day 5. The third specific aim was addressed with data collected during the same observational study of patients after trauma (n = 19). Participants provided measures of anxiety and depressive symptoms at baseline. Anxiety was not a predictor of delayed ambulation; however, depressive symptoms increased the likelihood of delayed ambulation by 67% (Odds Ratio [OR]: 1.67, 95% CI: 1.02 – 2.72, p = 0.041). Early ambulation was associated with significantly greater muscle strength and thickness as determined by dynamometry and muscle ultrasound, and depressive symptoms significantly increased the likelihood of delayed ambulation. Systematic evaluation of the association between trauma injury, immobility, skeletal muscle function and structure, and psychological state will provide an opportunity for the appropriate evaluation after injury and development of effective, tailored interventions to improve short- and long-term physiological and psychological recovery.

Thesis (Ph. D.)--University of Missouri--Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves: 104-107). Also available on the Internet.

Yes / Purpose: A recent randomised controlled trial indicated that providing long-term multifocal wearers with a pair of distance single-vision spectacles for use outside the home reduced falls risk in active older people. However, it also found that participants disliked continually switching between using two pairs of glasses and adherence to the intervention was poor. In this study we determined whether intermediate addition multifocals (which could be worn most of the time inside and outside the home and thus avoid continual switching) could provide similar gait safety on stairs to distance single vision spectacles whilst also providing adequate ‘short-term’ reading and near vision. Methods: Fourteen healthy long-term multifocal wearers completed stair ascent and descent trials over a 3-step staircase wearing intermediate and full addition bifocals and progression-addition lenses (PALs) and single-vision distance spectacles. Gait safety/caution was assessed using foot clearance measurements (toe on ascent, heel on descent) over the step edges and ascent and descent duration. Binocular near visual acuity, critical print size and reading speed were measured using Bailey-Lovie near charts and MNRead charts at 40 cm. Results: Gait safety/caution measures were worse with full addition bifocals and PALs compared to intermediate bifocals and PALs. The intermediate PALs provided similar gait ascent/descent measures to those with distance single- vision spectacles. The intermediate addition PALs also provided good reading ability: Near word acuity and MNRead critical print size were better with the intermediate addition PALs than with the single-vision lenses (p < 0.0001), with a mean near visual acuity of 0.24 0.13 logMAR (~N5.5) which is satisfactory for most near vision tasks when performed for a short period of time. Conclusions: The better ability to ‘spot read’ with the intermediate addition PALs compared to single-vision spectacles suggests that elderly individuals might better comply with the use of intermediate addition PALs outside the home. A lack of difference in gait parameters for the intermediate addition PALs compared to distance single-vision spectacles suggests they could be usefully used to help prevent falls in older well-adapted full addition PAL wearers. A randomised controlled trial to investigate the usefulness of intermediate multifocals in preventing falls seems warranted.