Whole body frontal plane mechanics across walking, running, and sprinting in young and older adults.

This study investigated the whole body frontal plane mechanics among young (26 ± 6 years), early old (61 ± 5 years), and old (78 ± 4 years) adults during walking, running, and sprinting. The age-groups had similar walking (1.6 m/s) and running (4.0 m/s) speeds, but different maximal sprinting speed (young 9.3 m/s, early old 7.9 m/s, and old 6.6 m/s). Surprisingly, although the old group exerted much lower vertical ground reaction force during running and sprinting, the hip frontal plane moment did not differ between the age-groups. Kinematic analysis demonstrated increased hip adduction and pelvis drop, as well as reduced trunk lateral flexion among old adults, especially during sprinting. These alterations in the hip and pelvis motions may reflect insufficient force production of hip abductors to stabilize the pelvis during single-limb support, while limited trunk lateral flexion may enhance control of the mediolateral balance. On the other hand, larger trunk side-to-side movement among the young and early old adults may provide a mechanism to prevent the increase of the hip frontal moment despite greater vertical ground reaction force. This, in turn, can assist hip abductors to maintain stability of the pelvis during sprinting while allowing powerful force generation by a large adductor muscle group.

Reconstruction of the vulva with sensate gluteal fold flaps.

BACKGROUND AND AIMS: Soft-tissue reconstruction of the vulva following resection of malignancies is challenging. The function of perineal organs should be preserved and the reconstructed area should maintain an acceptable cosmetic appearance. Reconstruction with local flaps is usually sufficient in the primary phase after a radical vulvectomy. Numerous flaps have been designed for vulvar reconstruction usually based on circulation from the internal pudendal artery branches. In this paper we introduce our modification of the gluteal fold V-Y advancement flap as a primary reconstruction after a radical vulvectomy. PATIENTS AND METHODS: Twenty-two patients were operated with a radical vulvectomy because of vulvar malignancies. The operation was primary in eight and secondary in 14 patients. The reconstruction of the vulva was performed in the same operation for each patient. RESULTS: All flaps survived completely. Wound complications were registered in three patients. Late problems with urinary stream were corrected in two patients. A local recurrence of the malignancy was observed in six patients during the follow-up period. CONCLUSIONS: Gluteal fold flap is easy to perform, has a low rate of complications and gives good functional results. Even a large defect can be reconstructed reliably with this method. A gluteal fold V-Y advancement flap is sensate and our modification allows the flap to be transposed with lesser dissection as presented before.

A full body musculoskeletal model based on flexible multibody simulation approach utilised in bone strain analysis during human locomotion.

Load-induced strains applied to bone can stimulate its development and adaptation. In order to quantify the incident strains within the skeleton, in vivo implementation of strain gauges on the surfaces of bone is typically used. However, in vivo strain measurements require invasive methodology that is challenging and limited to certain regions of superficial bones only such as the anterior surface of the tibia. Based on our previous study [Al Nazer et al. (2008) J Biomech. 41:1036-1043], an alternative numerical approach to analyse in vivo strains based on the flexible multibody simulation approach was proposed. The purpose of this study was to extend the idea of using the flexible multibody approach in the analysis of bone strains during physical activity through integrating the magnetic resonance imaging (MRI) technique within the framework. In order to investigate the reliability and validity of the proposed approach, a three-dimensional full body musculoskeletal model with a flexible tibia was used as a demonstration example. The model was used in a forward dynamics simulation in order to predict the tibial strains during walking on a level exercise. The flexible tibial model was developed using the actual geometry of human tibia, which was obtained from three-dimensional reconstruction of MRI. Motion capture data obtained from walking at constant velocity were used to drive the model during the inverse dynamics simulation in order to teach the muscles to reproduce the motion in the forward dynamics simulation. Based on the agreement between the literature-based in vivo strain measurements and the simulated strain results, it can be concluded that the flexible multibody approach enables reasonable predictions of bone strain in response to dynamic loading. The information obtained from the present approach can be useful in clinical applications including devising exercises to prevent bone fragility or to accelerate fracture healing.

Flexible multibody simulation approach in the analysis of tibial strain during walking.

Strains within the bone tissue play a major role in bone (re)modeling. These small strains can be assessed using experimental strain gage measurements, which are challenging and invasive. Further, the strain measurements are, in practise, limited to certain regions of superficial bones only, such as the anterior surface of the tibia. In this study, tibial strains occurring during walking were estimated using a numerical approach based on flexible multibody dynamics. In the introduced approach, a lower body musculoskeletal model was developed by employing motion capture data obtained from walking at a constant velocity. The motion capture data were used in inverse dynamics simulation to teach the muscles in the model to replicate the motion in forward dynamics simulation. The maximum and minimum tibial principal strains predicted by the model were 490 and -588 microstrain, respectively, which are in line with literature values from in vivo measurements. In conclusion, the non-invasive flexible multibody simulation approach may be used as a surrogate for experimental bone strain measurements and thus be of use in detailed strain estimations of bones in different applications.

Pretreatment plasma testosterone and estradiol levels in patients with locally advanced or metastasized prostatic cancer. FINNPROSTATE Group.

BACKGROUND: Studies concerning pretreatment plasma hormonal environment in relation to stage of prostatic cancer have given conflicting results. The aim of the present study was to compare the pretreatment plasma testosterone (T), free T (fT), estradiol (E2), and free E2 (fE2) levels in patients with locally advanced (T3-4 M0) and metastatic (T1-4 M1) prostatic cancer, and to further examine the effect of the patients' general condition on these levels. METHODS: The present series consisted of 238 patients (Finnprostate 6 study). The variables analyzed were E2, fE2, T, fT, age, body mass index (BMI), sex hormone binding globulin capacity (SHBG), prostate-specific antigen (PSA), alkaline phosphatase (ALP), hemoglobin concentration (Hb), erythrocyte sedimentation rate (ESR), and performance status (PS). RESULTS: The E2 and fE2 levels were significantly higher in M0 patients than in M1 patients, with no significant differences in T and fT levels. In multivariate analyses, a decline in performance status (PS), an increase in ESR, or a decrease in Hb, were related to a decrease in T, fT, E2, or fE2 levels. CONCLUSIONS: Pretreatment plasma estradiol was significantly lower in M1 patients than in M0 patients, but there were no significant differences in T levels, although the poor general condition was related to a decrease in the pretreatment levels of both testosterone and estradiol.

The role of parenteral polyestradiol phosphate in the treatment of advanced prostatic cancer on the threshold of the new millennium.

Orchiectomy and estrogens have been used for over 50 years in the treatment of advanced prostatic cancer. Although orchiectomy is a simple procedure, it may cause psychological stress. Oral estrogen therapy is as effective as orchiectomy in terms of cancer inhibitory effect, but its acceptance as primary hormonal treatment is overshadowed by an increased risk of cardiovascular complications. Parenteral estrogen, polyestradiol phosphate (PEP), is effective, but also associated with cardiovascular complications, although to a lesser extent. During the last 20 years, well tolerated luteinizing hormone releasing hormone (LHRH) analogues have been replacing orchiectomy and estrogens. Efforts have been made to increase the efficacy of the treatment by adding antiandrogens to LHRH analogues and also to orchiectomy (combined androgen blockade, CAB). However, the efficacy of LHRH analogues and CAB has not proved to be superior to that of simple orchiectomy and, moreover, they are expensive treatment modalities. Orchiectomy and LHRH analogues are associated with negative effects on bone mass and may cause osteoporosis, whereas PEP treatment has an opposite effect. Parenteral polyestradiol phosphate is still a cheap potential treatment for advanced prostatic cancer, but further studies should be conducted to establish its future role, e.g. combining acetylsalicylic acid to prevent cardiovascular complications.

Parenteral polyoestradiol phosphate vs orchidectomy in the treatment of advanced prostatic cancer. Efficacy and cardiovascular complications: a 2-year follow-up report of a national, prospective prostatic cancer study. Finnprostate Group.

OBJECTIVE: To evaluate the clinical efficacy and cardiovascular complications of orchidectomy or polyoestradiol phosphate (PEP) in the treatment of advanced prostatic cancer. PATIENTS AND METHODS: In a prospective, randomized study 444 patients (mean age 73 years, range 45-91) with T3-4 M0 or T1-4 M1 prostatic cancer were treated either by orchidectomy (group 1, n = 217) or parenteral PEP (group 2, n = 227; 240 mg/month). The patients were examined at 3 and 6 months after start of the therapy and thereafter every 6 months; they were also assessed whenever they had symptoms indicating progression. Possible cardiovascular complications included myocardial infarction, cerebrovascular accident, pulmonary embolism and deep vein thrombosis. RESULTS: After a follow-up of 2 years there was no statistically significant difference between the groups in progression-free time; 65 of 217 (30%) patients in group 1 showed evidence of progression, including seven (3%) who died from prostate cancer. In group 2, 64 of 227 (28%) patients showed progression and eight (3.5%) died from prostatic cancer. There were 10 (5%) cardiovascular complications in patients in group 1, including five (2%) cardiovascular deaths; in group 2 there were 24 (11%) and 14 (6%), respectively. During the first year of treatment there were three (1.4%) cardiovascular complications in group 1 and 14 (6%) in group 2 (P < 0.05), and during the second year, seven (4%) and 10 (6%), respectively. CONCLUSION: Parenteral PEP (240 mg/month) seems to be as efficient as orchidectomy in inhibiting disease in patients with advanced prostatic cancer (T3-4 M0 and T1-4 M1). There were more cardiovascular complications in patients treated with PEP than after orchidectomy; the difference was statistically significant during the first year of treatment.