Dan K. Ramsey

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BACKGROUND Temporal-spatial gait parameters improve following total knee arthroplasty (TKA) but lower limb kinematics and moments fail to match those of age-matched healthy individuals. The aim of this study was to determine whether quadriceps strength, clinical measures of knee function, lower limb kinematics, and joint moments improve following(More)
We investigated the accuracy of a linear soft tissue artefact (STA) model in human movement analysis. Simultaneously recorded bone-mounted pin and skin marker data for the thigh and shank during walking, cutting and hopping were used to measure and model the motion of the skin marker clusters within anatomical reference frames (ARFs). This linear model(More)
Eight healthy male subjects had intra-cortical bone-pins inserted into the proximal tibia and distal femur. Three reflective markers were attached to each bone-pin and four reflective markers were mounted on the skin of the tibia and thigh, respectively. Roentgen-stereophotogrammetric analysis (RSA) was used to determine the anatomical reference frame of(More)
BACKGROUND Evidence that knee braces used for the treatment of osteoarthritis mediate pain relief and improve function by unloading the joint (increasing the joint separation) remains inconclusive. Alternatively, valgus-producing braces may mediate pain relief by mechanically stabilizing the joint and reducing muscle cocontractions and joint compression. In(More)
The purpose of this review article is twofold: to report on the use of intracortical pins to measure three-dimensional tibiofemoral and patellofemoral joint kinematics and highlight methodological concerns associated with this procedure. Tibiofemoral and patellofemoral kinematics has been extensively investigated using reflective markers attached to the(More)
The purpose of this study was to investigate postural control in women with and without premenstrual symptoms (PMS) in three hormonally verified phases of the menstrual cycle. Thirty-two women were recruited to participate in the study and 25 of these women were included in the results. Menstrual cycle phases were determined by sex hormone analyses in serum(More)
OBJECTIVE To determine whether knee flexion influenced bony contact movements during flexion. DESIGN Accurate three-dimensional (3D) measurements of tibiofemoral bony contact points in vivo was performed using magnetic resonance imaging technology at 0 degrees, 30 degrees and 60 degrees of flexion. BACKGROUND Magnetic resonance imaging is an accurate(More)
OBJECTIVE Individuals with medial compartment knee osteoarthritis (OA) and genu varum use different movement and muscle activation patterns to increase joint stability during gait. The purpose of this study was to ascertain whether opening-wedge high-tibial osteotomy (OW-HTO) corrected pathomechanical abnormalities associated with the progression of knee(More)
The goal of opening wedge high tibial osteotomy (HTO) is to reduce excessive loading on the medial compartment of the knee by correcting varus deformity, thereby reducing pain and improving function. Although surgical outcome is reportedly poor in cases of under- or overcorrection, the recommended alignment varies. The aim of this study was to investigate(More)
We investigated the effects of including kinematic constraints in the analysis of knee kinematics from skin markers and compared the result to simultaneously recorded trajectories of bone pin markers during gait of six healthy subjects. The constraint equations that were considered for the knee were spherical and revolute joints, which have been frequently(More)