Minimum toe clearance and tripping probability in people with unilateral transtibial amputation walking on ramps with different prosthetic designs.

BACKGROUND: Minimum Toe Clearance (MTC) is defined as the minimum vertical distance between the lowest point under the front part of the foot and the ground, during mid-swing. Low values of MTC and walking on inclines are both related to higher probability of tripping and falling in lower limb amputees. New prosthetic designs aim at improving MTC, especially on ramps, however the real effect on MTC still needs investigation. The objective of this study was then to evaluate the effect of different prosthetic designs on MTC in inclined walking. METHODS: Thirteen transtibial amputees walked on a ramp using three different prostheses: non articulating ankle (NAA), articulating hydraulic ankle (AHA), and articulating hydraulic ankle with microprocessor (AHA-MP). Median MTC, coefficient of variation (CV), and tripping probability (TP) for obstacles of 10 and 15 mm were compared across ankle type in ascent and descent. FINDINGS: When using AHA-MP, larger MTC median values for ascending (P ≤ 0.001, W = 0.58) and descending the ramp (P = 0.003, W = 0.47) were found in the prosthetic limb. Also significantly lower CV was found on the prosthetic limb for both types of AHA feet when compared to NAA for descending the ramp (P = 0.014, W = 0.45). AHA-MP showed the lowest TP for the prosthetic leg in three conditions evaluated. On the sound limb results showed the median MTC was significantly larger (P = 0.009, W = 0.43) and CV significantly lower (P = 0.005, W = 0.41) when using an AHA in ascent. INTERPRETATION: Both AHA prosthetic designs help reduce the risk of tripping of the prosthetic limb by increasing the median MTC, lowering its variability and reducing TP for both legs when ascending and descending the ramp. For most of the conditions, AHA-MP showed the lowest TP values. Findings suggest that AHA prostheses, especially AHA-MP could reduce the risk of tripping on ramps in amputees.

Recuperación de la frecuencia cardíaca post ejercicio en enfermos respiratorios crónicos

Las enfermedades respiratorias crónicas se asocian frecuentemente con disfunción autonómica cardíaca y esta se puede evaluar midiendo la recuperación de la frecuencia cardíaca (RFC) post ejercicio. Existen evidencias que la RFC calculada luego de un minuto de reposo después de la prueba de marcha de seis minutos (PM6M) puede predecir mortalidad y exacerbaciones agudas en pacientes con enfermedades respiratorias crónicas. El objetivo de este trabajo fue comparar la recuperación de la frecuencia cardíaca al finalizar una prueba del escalón de tres minutos de duración (PE3M) en enfermos respiratorios crónicos con la obtenida al finalizar la PM6M. La PE3M se realizó sin dificultad en un consultorio de reducidas dimensiones y todos los pacientes pudieron terminarlo. Aplicando el índice de correlación de Pearson se obtuvo como resultado 0,84 al comparar la RCF al minuto de detenerse en ambas pruebas lo que muestra una buena correlación entre ellas. En el gráfico de Bland Altman, se observa que los resultados están dentro de los límites de confianza mostrando concordancia a pesar de ser una muestra pequeña de pacientes. La PE3M se realiza con facilidad en un pequeño consultorio. Los resultados de la RCF después de esta prueba son comparables a los obtenidos al finalizar la PM6M.

Post-exercise Heart Rate Recovery in Patients with Chronic Respiratory Disease

Chronic respiratory diseases are frequently associated with cardiac autonomic dysfunction and this can be evaluated by measuring post-exercise heart rate recovery (HRR). There is evidence that the HRR calculated after one minute of rest following a Six-Minute Walk Test (6MWT) can predict mortality and acute exacerbations in patients with chronic respiratory diseases. The purpose of this study is to compare the heart rate recovery after finishing a Three-Minute Step Test (3MST) in chronic respiratory patients with that obtained after the 6MWT. The 3MST was performed without difficulty in a small doctor's office and all the patients were able to finish it. Applying the Pearson Correlation Index, the result was 0.84 when comparing the HRR one minute after stopping in both tests, showing a good correlation between them. In the Bland-Altman Plot, we can see that the results are within the confidence limits and show concordance despite being a small sample of patients. The 3MST is easily done in a small doctor's office. The results of the HRR after the 3MST are comparable to those obtained after finishing the 6MWT.