A randomized controlled trial of a shared decision making intervention for diabetes prevention for women with a history of gestational diabetes mellitus: The Gestational diabetes Risk Attenuation for New Diabetes (GRAND study).

BACKGROUND: Gestational diabetes mellitus (GDM) is a risk factor for the development of type 2 diabetes. Metformin and lifestyle change through a Diabetes Prevention Program (DPP) are equally effective in preventing diabetes in patients with a GDM history, so women can choose a strategy based on their preferences. This study aims to test whether shared decision making (SDM) can help women with a history of GDM increase adoption of evidence-based strategies and lose weight to lower their risk of incident diabetes in real-world settings. METHODS: This pragmatic randomized controlled trial (RCT) will test the effectiveness of SDM for diabetes prevention among 310 overweight/obese women with a history of GDM and prediabetes from two large health care systems (n = 155 from UCLA Health and n = 155 from Intermountain Healthcare). The primary outcome is the proportion of participants who lose ≥5% body weight at 12 months. Secondary outcomes include uptake of DPP and/or metformin and other patient-reported outcomes such as patient activation and health-related quality of life. Rates of GDM in a subsequent pregnancy will be an exploratory outcome. A descriptive analysis of costs related to SDM implementation will also be conducted. CONCLUSION: This is the first RCT to examine the effectiveness of SDM on weight loss, lifestyle change and/or metformin use, and other patient-reported outcomes in participants with a GDM history at risk of developing diabetes. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03766256. Registered on 6 December 2018.

High knee valgus in female subjects does not yield higher knee translations during drop landings: a biplane fluoroscopic study.

The goal of this study was to determine the effects of peak knee valgus angle and peak knee abductor moment on the anterior, medial, and lateral tibial translations (ATT, MTT, LTT) in the "at risk" female knee during drop landing. Fifteen female subjects performed drop landings from 40 cm. Three-dimension knee motion was simultaneously recorded using a high speed, biplane fluoroscopy system, and a video-based motion analysis system. Valgus knee angles and knee abduction moments were stratified into low, intermediate, and high groups and peak ATT, MTT, and LTT were compared between these groups with ANOVA (α = 0.05). Significant differences were observed between stratified groups in peak knee valgus angle (p < 0.0001) and peak knee abduction moment (p < 0.0001). However, no corresponding differences in peak ATT, LTT, and MTT between groups exhibiting low to high-peak knee valgus angles (ATT: p = 0.80; LTT: p = 0.25; MTT: p = 0.72); or, in peak ATT (p = 0.61), LTT (p = 0.26) and MTT (p = 0.96) translations when stratified according to low to high knee abduction moments, were found. We conclude that the healthy female knee is tightly regulated with regard to translations even when motion analysis derived knee valgus angles and abduction moments are high.

Relationship of knee shear force and extensor moment on knee translations in females performing drop landings: a biplane fluoroscopy study.

BACKGROUND: Research has linked knee extensor moment and knee shear force to the non-contact anterior cruciate ligament injury during the landing motion. However, how these biomechanical performance factors relate to knee translations in vivo is not known as knee translations cannot be obtained with traditional motion capture techniques. The purpose of this study was to combine traditional motion capture with high-speed, biplane fluoroscopy imaging to determine relationships between knee extensor moment and knee shear force profiles with anterior and lateral tibial translations occurring during drop landing in female athletes. METHODS: 15 females performed drop landings from a height of 40 cm while being recorded using a high speed, biplane fluoroscopy system and simultaneously being recorded using surface marker motion capture techniques to estimate knee joint angle, reaction force and moment profiles. FINDINGS: No significant statistical relationships were observed between peak anterior or posterior knee shear force and peak anterior and lateral tibial translations; or, between peak knee extensor moment and peak anterior and lateral tibial translations. Although differences were noted in peak shear force (P=0.02) and peak knee extensor moment (P<0.001) after stratification into low and high shear force and moment cohorts, no differences were noted in anterior and lateral tibial translations (all P ≥ 0.18). INTERPRETATION: Females exhibiting high knee extensor moment and knee shear force during drop landings do not yield correspondingly high anterior and lateral tibial translations.

Measurements of tibiofemoral kinematics during soft and stiff drop landings using biplane fluoroscopy.

BACKGROUND: Previous laboratory studies of landing have defined landing techniques in terms of soft or stiff landings according to the degree of maximal knee flexion angle attained during the landing phase and the relative magnitude of the ground-reaction force. Current anterior cruciate ligament injury prevention programs are instructing athletes to land softly to avoid excessive strain on the anterior cruciate ligament. PURPOSE: This study was undertaken to measure, describe, and compare tibiofemoral rotations and translations of soft and stiff landings in healthy individuals using biplane fluoroscopy. STUDY DESIGN: Controlled laboratory study. METHODS: The in vivo, lower extremity, 3-dimensional knee kinematics of 16 healthy adults (6 male and 10 female) instructed to land softly and stiffly in different trials were collected in biplane fluoroscopy as they performed the landing from a height of 40 cm. RESULTS: Average and maximum relative anterior tibial translation (average, 2.8 ± 1.2 mm vs 3.0 ± 1.4 mm; maximum, 4.7 ± 1.6 mm vs 4.4 ± 0.8 mm), internal/external rotation (average, 3.7° ± 5.1° vs 2.7° ± 4.3°; maximum, 5.6° ± 5.5° vs 4.9° ± 4.7°), and varus/valgus (average, 0.2° ± 1.2° vs 0.2° ± 1.0°; maximum, 1.7° ± 1.2° vs 1.6° ± 0.9°) were all similar between soft and stiff landings, respectively. The peak vertical ground-reaction force was significantly larger for stiff landings than for soft landings (2.60 ± 1.32 body weight vs 1.63 ± 0.73; P < .001). The knee flexion angle total range of motion from the minimum angle at contact to the maximum angle at peak knee flexion was significantly greater for soft landings than for stiff (55.4° ± 8.8° vs 36.8° ± 11.1°; P < .01). CONCLUSION: Stiff landings, as defined by significantly lower knee flexion angles and significantly greater peak ground-reaction forces, do not result in larger amounts of anterior tibial translation or knee rotation in either varus/valgus or internal/external rotation in healthy individuals. CLINICAL RELEVANCE: In healthy knees, the musculature and soft tissues of the knee are able to maintain translations and rotations within a small, safe range during controlled landing tasks of differing demand. The knee kinematics of this healthy population will serve as a comparison for injured knees in future studies. It should be stressed that because the authors did not compare how the loads were distributed over the soft tissues of the knee between the 2 landing styles, the larger ground-reaction forces and more extended knee position observed during stiff landings should still be considered dangerous to the anterior cruciate ligament and other structures of the lower extremities, particularly in competitive settings where movements are often unanticipated.

Knee kinematic profiles during drop landings: a biplane fluoroscopy study.

INTRODUCTION: The six degrees of freedom knee motion during dynamic activities is not well understood. PURPOSE: Biplane fluoroscopy was used to measure the three-dimensional rotations and translations of healthy knees during stiff drop landings and to determine the relationships between three-dimensional rotations and anterior (ATT) and lateral tibial translations (LTT). METHODS: Six males performed stiff drop landings from 40 cm while being filmed using a high-speed, biplane fluoroscopy system. Initial, peak, and excursions for rotations and translations were calculated, and relationships and changes in these variables were assessed (α = 0.05). RESULTS: Knee flexion at contact was 13.9° ± 9.2° (mean ± SD) and increased to a peak of 44.0° ± 17.2° with an excursion of 31.5° ± 14.1°. Knee varus/valgus angle at contact was -0.3° ± 1.8° varus; subjects progressed into a mean peak valgus position of 1.5° ± 0.9° with total excursion of 2.5° ± 0.9°. Four of six subjects landed externally rotated (2.5° ± 3.0°); two landed internally rotated (-4.9° ± 1.5°), yielding a contact angle of -2.4° ± 3.0° of internal rotation, a peak internal rotation of -5.5° ± 6.0°, and excursion of 3.1° ± 5.5°. Peak ATT were 4.3 ± 0.7 mm (excursion = 2.1 ± 0.9 mm), occurring within 50 ms after contact. Peak LTT were 1.5 ± 1.4 mm (excursion = 2.6 ± 1.6 mm). Significant regressions were found between ATT and knee valgus angle (r2 = 0.39, P = 0.006), between LTT and internal rotation (r2 = 0.96, P < 0.0001), and between LTT and knee valgus angle (quadratic, r2 = 0.90, P < 0.0001). CONCLUSION: This study provides a direct correlation between knee valgus angle with knee ATT and LTT during drop landings.