RESUMEN
The aim of this study was to evaluate tracking performance when an extra reference block is added to a basic block-matching method, where the two reference blocks originate from two consecutive ultrasound frames. The use of an extra reference block was evaluated for two putative benefits: (i) an increase in tracking performance while maintaining the size of the reference blocks, evaluated using in silico and phantom cine loops; (ii) a reduction in the size of the reference blocks while maintaining the tracking performance, evaluated using in vivo cine loops of the common carotid artery where the longitudinal movement of the wall was estimated. The results indicated that tracking accuracy improved (mean = 48%, p < 0.005 [in silico]; mean = 43%, p < 0.01 [phantom]), and there was a reduction in size of the reference blocks while maintaining tracking performance (mean = 19%, p < 0.01 [in vivo]). This novel method will facilitate further exploration of the longitudinal movement of the arterial wall.
Asunto(s)
Arteria Carótida Común/diagnóstico por imagen , Ultrasonografía/métodos , Algoritmos , Arteria Carótida Común/fisiología , Simulación por Computador , Procesamiento de Imagen Asistido por Computador/métodos , Movimiento/fisiología , Fantasmas de ImagenRESUMEN
BACKGROUND: Impaired hand function is common in patients with arthritis and it affects performance of daily activities; thus, hand exercises are recommended. There is little information on the extent to which the disease affects activation of the flexor and extensor muscles during these hand-dexterity tasks. The purpose of this study was to compare muscle activation during such tasks in subjects with arthritis and in a healthy reference group. METHODS: Muscle activation was measured in m. extensor digitorium communis (EDC) and in m. flexor carpi radialis (FCR) with surface electromyography (EMG) in women with rheumatoid arthritis (RA, n = 20), hand osteoarthritis (HOA, n = 16) and in a healthy reference group (n = 20) during the performance of four daily activity tasks and four hand exercises. Maximal voluntary isometric contraction (MVIC) was measured to enable intermuscular comparisons, and muscle activation is presented as %MVIC. RESULTS: The arthritis group used a higher %MVIC than the reference group in both FCR and EDC when cutting with a pair of scissors, pulling up a zipper and-for the EDC-also when writing with a pen and using a key (p < 0.02). The exercise "rolling dough with flat hands" required the lowest %MVIC and may be less effective in improving muscle strength. CONCLUSIONS: Women with arthritis tend to use higher levels of muscle activation in daily tasks than healthy women, and wrist extensors and flexors appear to be equally affected. It is important that hand training programs reflect real-life situations and focus also on extensor strength.
Asunto(s)
Artritis Reumatoide/fisiopatología , Mano/fisiopatología , Músculo Esquelético/fisiopatología , Osteoartritis/fisiopatología , Actividades Cotidianas , Anciano , Electromiografía , Ejercicio Físico , Femenino , Fuerza de la Mano , Humanos , Contracción Isométrica , Persona de Mediana Edad , Movimiento , Fuerza Muscular , Servicio Ambulatorio en HospitalRESUMEN
OBJECTIVE: Balance between flexor and extensor muscle activity is essential for optimal function. The purpose of this pilot study was to compare the relationship between maximum finger flexion force and maximum finger extension force in women with rheumatoid arthritis and healthy women. METHODS: Twenty healthy women (median age 61 years) and 20 women with rheumatoid arthritis (median age 59.5 years, median disease duration 16.5 years) were included in the study. Finger extension force was measured with an electronic device, EX-it, and finger flexion force using Grippit. The Grip Ability Test and the score from the patient-reported outcome Disability Arm Shoulder and Hand were used to evaluate activity limitations. RESULTS: Patients with rheumatoid arthritis showed significantly decreased hand function compared with healthy controls. A correlation was found between extension force and flexion force in the healthy group (r = 0.65, p = 0.002),but not in the rheumatoid arthritis group (r = 0.25, p = 0.289). CONCLUSION: Impaired hand function appears to influence the relationship between maximum finger flexion and extension force. This study showed a difference in the relationship between maximum finger flexion and extension force in healthy controls and those with rheumatoid arthritis.
Asunto(s)
Artritis Reumatoide/patología , Dedos/fisiología , Fuerza Muscular/fisiología , Rango del Movimiento Articular/fisiología , Actividades Cotidianas , Adulto , Anciano , Femenino , Dedos/patología , Encuestas Epidemiológicas , Humanos , Persona de Mediana Edad , Músculo Esquelético , Estadística como Asunto , Factores de Tiempo , Salud de la MujerRESUMEN
Equipment used in sports is of great importance, especially when the equipment is in direct contact with the athlete or is important for safety. In the sport kitesurfing environmental factors and the equipment design are crucial for the comfort and safety. The participants' choice and opinion of equipment can show which factors are considered most important for the performance and to reduce risk for injury. This study has evaluated self-reported information from the participants about what equipment they use, comfort of the equipment and if the equipment has contributed to any injuries. The methods used were questionnaires (n=206) and interviews (n=17), which in combination allows to assess the problem both quantitatively and qualitatively. The results showed that supported leading edge kites are most frequently used, with a waist harness and foot straps to attach the feet. The choice of kite type was mainly based on the discipline of riding for the respondent. Some issues concerning comfort of riding and injury risk the respondents did relate to the design of harness and foot straps. The information from this study can be used for development strategies for industry manufacturers and for further studies in the area of equipment design and biomechanics.
Asunto(s)
Seguridad , Equipo Deportivo , Deportes , Adolescente , Adulto , Traumatismos en Atletas/etiología , Comportamiento del Consumidor , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Equipo Deportivo/efectos adversos , Adulto JovenRESUMEN
OBJECTIVE: To evaluate the effects of hand exercise in patients with rheumatoid arthritis, and to compare the results with healthy controls. METHODS: Forty women (20 patients with rheumatoid arthritis and 20 healthy controls) performed a hand exercise programme. The results were evaluated after 6 and 12 weeks with hand force measurements (with a finger extension force measurement device (EX-it) and finger flexion force measurement with Grippit). Hand function was evaluated with the Grip Ability Test (GAT) and with patient relevant questionnaires (Disability of the Arm, Shoulder, and Hand (DASH) and Short Form-36). Ultrasound measurements were performed on m. extensor digitorum communis for analysis of the muscle response to the exercise programme. RESULTS: The extension and flexion force improved in both groups after 6 weeks (p < 0.01). Hand function (GAT) also improved in both groups (p < 0.01). The rheumatoid arthritis group showed improvement in the results of the DASH questionnaire (p < 0.05). The cross-sectional area of the extensor digitorum communis increased significantly in both groups measured with ultrasound. CONCLUSION: A significant improvement in hand force and hand function in patients with rheumatoid arthritis was seen after 6 weeks of hand training; the improvement was even more pronounced after 12 weeks. Hand exercise is thus an effective intervention for rheumatoid arthritis patients, leading to better strength and function.
Asunto(s)
Artritis Reumatoide/rehabilitación , Terapia por Ejercicio , Adulto , Anciano , Artritis Reumatoide/diagnóstico por imagen , Artritis Reumatoide/fisiopatología , Femenino , Mano/fisiopatología , Fuerza de la Mano/fisiología , Humanos , Persona de Mediana Edad , Músculo Esquelético/diagnóstico por imagen , Evaluación de Resultado en la Atención de Salud , Encuestas y Cuestionarios , Factores de Tiempo , Resultado del Tratamiento , UltrasonografíaRESUMEN
BACKGROUND: The aim of this study was to evaluate the usefulness of an ultrasound-based method of examining extensor muscle architecture, especially the parameters important for force development. This paper presents the combination of two non-invasive methods for studying the extensor muscle architecture using ultrasound simultaneously with finger extension force measurements. METHODS: M. extensor digitorum communis (EDC) was examined in 40 healthy subjects, 20 women and 20 men, aged 35-73 years. Ultrasound measurements were made in a relaxed position of the hand as well as in full contraction. Muscle cross-sectional area (CSA), pennation angle and contraction patterns were measured with ultrasound, and muscle volume and fascicle length were also estimated. Finger extension force was measured using a newly developed finger force measurement device. RESULTS: The following muscle parameters were determined: CSA, circumference, thickness, pennation angles and changes in shape of the muscle CSA. The mean EDC volume in men was 28.3 cm3 and in women 16.6 cm3. The mean CSA was 2.54 cm2 for men and 1.84 cm2 for women. The mean pennation angle for men was 6.5 degrees and for women 5.5 degrees . The mean muscle thickness for men was 1.2 cm and for women 0.76 cm. The mean fascicle length for men was 7.3 cm and for women 5.0 cm. Significant differences were found between men and women regarding EDC volume (p < 0.001), CSA (p < 0.001), pennation angle (p < 0.05), muscle thickness (p < 0.001), fascicle length (p < 0.001) and finger force (p < 0.001). Changes in the shape of muscle architecture during contraction were more pronounced in men than women (p < 0.01). The mean finger extension force for men was 96.7 N and for women 39.6 N. Muscle parameters related to the extension force differed between men and women. For men the muscle volume and muscle CSA were related to extension force, while for women muscle thickness was related to the extension force. CONCLUSION: Ultrasound is a useful tool for studying muscle architectures in EDC. Muscle parameters of importance for force development were identified. Knowledge concerning the correlation between muscle dynamics and force is of importance for the development of new hand training programmes and rehabilitation after surgery.