Search results for "ALK"
showing 10 items of 4314 documents
Walking and Running Require Greater Effort from the Ankle than the Knee Extensor Muscles.
2016
The knee and ankle extensors as human primary antigravity muscle groups are of utmost importance in a wide range of locomotor activities. Yet, we know surprisingly little about how these muscle groups work, and specifically, how close to their maximal capacities they function across different modes and intensity of locomotion. Therefore, to advance our understanding of locomotor constraints, we determined and compared relative operating efforts of the knee and ankle extensors during walking, running, and sprinting.Using an inverse dynamics biomechanical analysis, the muscle forces of the knee and ankle extensors during walking (1.6 m·s), running (4.1 m·s), and sprinting (9.3 m·s) were quant…
Osteogenic differentiation of periodontal fibroblasts is dependent on the strength of mechanical strain
2012
Abstract Objective During orthodontic therapy the correct strength of mechanical strain plays a key role for bone remodelling during tooth movement. Aim of this study was to investigate the osteogenic differentiation of human periodontal ligament fibroblasts (HPdLF) depending on the applied strength of mechanical strain compared to osteoblasts (HOB). Design HPdLF and HOB were loaded with different strengths (1%, 5% and 10%) of static mechanical strain (SMS) for 12 h in vitro. Viability was verified by MTT and apoptosis by TUNEL assay. Gene expression of cyclin D1, collagen type-1 (COL-I), alkaline phosphatase (ALP), osteocalcin, osteoprotegerin (OPG) and receptor activator of the NF-κB liga…
Neridronate prevents bone loss in patients receiving androgen deprivation therapy for prostate cancer.
2004
Today, androgen deprivation therapy is a cornerstone of treatment for advanced prostate cancer, although it presents important complications such as osteoporosis. Neridronate, a relatively new bisphosphonate, is able to prevent bone loss in patients with prostate cancer during androgen ablation. Introduction: Androgen-deprivation therapy (ADT) is a cornerstone of treatment for advanced prostate cancer. This therapy has iatrogenic complications, such as osteoporosis. The aim of our study was to evaluate the efficacy of neridronate, a relatively new bisphosphonate, to prevent bone loss during androgen ablation. Materials and Methods: Forty-eight osteoporotic patients with prostate cancer, tre…
Knee extensor and flexor muscle power explains stair ascension time in patients with unilateral late-stage knee osteoarthritis: a cross-sectional stu…
2014
To determine the extent of asymmetrical deficits in knee extensor and flexor muscles, and to examine whether asymmetrical muscle deficits are associated with mobility limitations in persons with late-stage knee osteoarthritis (OA).Cross-sectional.Research laboratory.A clinical sample (N=56; age range, 50-75y) of eligible persons with late-stage knee OA awaiting knee replacement.Not applicable.Knee extensor and flexor power and torque assessed isokinetically; thigh muscle cross-sectional area (CSA) assessed by computed tomography; mobility limitation assessed by walking speed and stair ascension time; and pain assessed with the Western Ontario and McMaster Universities Osteoarthritis Index q…
Biomechanical effectiveness of a distraction-rotation knee brace in medial knee osteoarthritis: preliminary results.
2013
Abstract Background Non-pharmacological therapies are recommended for the care of knee osteoarthritis patients. Unloader knee braces provide an interesting functional approach, which aims to modulate mechanical stress on the symptomatic joint compartment. We aimed to confirm the biomechanical effects and evaluate functional benefits of a new knee brace that combines a valgus effect with knee and tibial external rotation during gait in medial osteoarthritis patients. Methods Twenty patients with unilateral symptomatic medial knee osteoarthritis were included and they performed two test sessions of 3D gait analysis with and without the brace at the initial evaluation (W0) and after 5weeks (W5…
Muscle deficits persist after unilateral knee replacement and have implications for rehabilitation.
2009
BackgroundKnee joint arthritis causes pain, decreased range of motion, and mobility limitation. Knee replacement reduces pain effectively. However, people with knee replacement have decreases in muscle strength (“force-generating capacity”) of the involved leg and difficulties with walking and other physical activities.Objective and DesignThe aim of this cross-sectional study was to determine the extent of deficits in knee extensor and flexor muscle torque and power (ability to perform work over time) and in the extensor muscle cross-sectional area (CSA) after knee joint replacement. In addition, the association of lower-leg muscle deficits with mobility limitations was investigated.Methods…
Does the increase in body weight change the knee and ankle joint loading in walking and running?
2015
Previous obese studies showed that there is a correlation of weight to joint load in the knee joint during walking. In load-carrying studies, there are several studies but no consistent findings in the knee joint loads in walking and running. Our aim was to investigate how the joint load changes in body weight gaining, using added vest that was 10% of the body weight to mimic the conditions. We used Vicon eight-camera system and five force platforms with inverse dynamics to calculate the peak ground reaction forces(GRFs), joint angle, joint moments, and patellofemoral contact forces(PFCF), patellafemoral stress(PFS), peak patellofemoral tendon force(PTF) and peak Achilles tendon force (ATF)…
Impaired geometric properties of tibia in older women with hip fracture history.
2007
This study evaluated side-to-side differences in tibial mineral mass and geometry in women with previous hip fracture sustained on average 3.5 years earlier. Both tibial mineral mass and geometry were found to be reduced in the fractured leg. INTRODUCTION: The purpose of this study was to evaluate side-to-side differences in tibial mineral mass and geometry after hip fracture and to assess the determinants of such differences. METHODS: Thirty-eight 60- to 85-year-old women with a previous hip fracture and 22 same-aged control women without fractures participated in the study. Bone characteristics of the distal tibia and tibial shaft of both legs were assessed using pQCT in order to compare …
Does hysterectomy with ovarian conservation affect bone metabolism and density?
2002
We evaluated whether hysterectomy with ovarian conservation (HYX) has an effect on bone metabolism and density in 176 healthy Caucasian postmenopausal women aged 48-59 years. Bone properties of the hip, spine, radius, tibia, and calcaneus were measured using different bone assessment modalities. In addition, bone turnover was assessed using serum bone-specific alkaline phosphatase (BAP), osteocalcin (OC), and tartrate-resistant acid phosphatase (TRAP) 5b as biomarkers. Our results showed that women having HYX had a significantly lower level of OC ( P = 0.017) and a marginally lower level of TRAP 5b ( P = 0.051) and higher bone mineral density (BMD) of the femoral neck ( P = 0.037) and lumba…
Speed-Related Energy Flow and Joint Function Change During Human Walking.
2021
During human walking, mechanical energy transfers between segments via joints. Joint mechanics of the human body are coordinated with each other to adapt to speed change. The aim of this study is to analyze the functional behaviors of major joints during walking, and how joints and segments alter walking speed during different periods (collision, rebound, preload, and push-off) of stance phase. In this study, gait experiment was performed with three different self-selected speeds. Mechanical works of joints and segments were determined with collected data. Joint function indices were calculated based on net joint work. The results show that the primary functional behaviors of joints would n…