Audrey Zucker-Levin

Effects of a 6-Week, Individualized, Supervised Exercise Program for People With Bleeding Disorders and Hemophilic Arthritis

Background People with bleeding disorders may develop severe arthritis due to joint hemorrhages. Exercise is recommended for people with bleeding disorders, but guidelines are vague and few studies document efficacy. In this study, 65% of people with bleeding disorders surveyed reported participating in minimal exercise, and 50% indicated a fear of exercise-induced bleeding, pain, or physical impairment. Objective The purpose of this study was to examine the feasibility, safety, and efficacy of a professionally designed, individualized, supervised exercise program for people with bleeding disorders. Design A single-group, pretest-posttest clinical design was used. Methods Thirty-three patients (3 female, 30 male; 7–57 years of age) with mild to severe bleeding disorders were enrolled in the study. Twelve patients had co-existing illnesses, including HIV/AIDS, hepatitis, diabetes, fibromyalgia, neurofibromatosis, osteopenia, osteogenesis imperfecta, or cancer. Pre- and post-program measures included upper- and lower-extremity strength (force-generating capacity), joint range of motion, joint and extremity circumference, and distance walked in 6 minutes. Each patient was prescribed a 6-week, twice-weekly, individualized, supervised exercise program. Twenty participants (61%) completed the program. Results Pre- and post-program data were analyzed by paired t tests for all participants who completed the program. No exercise-induced injuries, pain, edema, or bleeding episodes were reported. Significant improvements occurred in joint motion, strength, and distance walked in 6 minutes, with no change in joint circumference. The greatest gains were among the individuals with the most severe joint damage and coexisting illness. Limitations Limitations included a small sample size with concomitant disease, which is common to the population, and a nonblinded examiner. Conclusions A professionally designed and supervised, individualized exercise program is feasible, safe, and beneficial for people with bleeding disorders, even in the presence of concomitant disease. A longitudinal study with a larger sample size, a blinded examiner, and a control group is needed to confirm the results.

Antidepressant Use and Recurrent Falls in Community-Dwelling Older Adults Findings From the Health ABC Study

Background: Few studies have compared the risk of recurrent falls across various antidepressant agents—using detailed dosage and duration data—among community-dwelling older adults, including those who have a history of a fall/fracture. Objective: To examine the association of antidepressant use with recurrent falls, including among those with a history of falls/fractures, in community-dwelling elders. Methods: This was a longitudinal analysis of 2948 participants with data collected via interview at year 1 from the Health, Aging and Body Composition study and followed through year 7 (1997-2004). Any antidepressant medication use was self-reported at years 1, 2, 3, 5, and 6 and further categorized as (1) selective serotonin reuptake inhibitors (SSRIs), (2) tricyclic antidepressants, and (3) others. Dosage and duration were examined. The outcome was recurrent falls (≥2) in the ensuing 12-month period following each medication data collection. Results: Using multivariable generalized estimating equations models, we observed a 48% greater likelihood of recurrent falls in antidepressant users compared with nonusers (adjusted odds ratio [AOR] = 1.48; 95% CI = 1.12-1.96). Increased likelihood was also found among those taking SSRIs (AOR = 1.62; 95% CI = 1.15-2.28), with short duration of use (AOR = 1.47; 95% CI = 1.04-2.00), and taking moderate dosages (AOR = 1.59; 95% CI = 1.15-2.18), all compared with no antidepressant use. Stratified analysis revealed an increased likelihood among users with a baseline history of falls/fractures compared with nonusers (AOR = 1.83; 95% CI = 1.28-2.63). Conclusion: Antidepressant use overall, SSRI use, short duration of use, and moderate dosage were associated with recurrent falls. Those with a history of falls/fractures also had an increased likelihood of recurrent falls.

Increased hip abduction in high body mass index subjects during sit-to-stand

Obesity is associated with increased risk of total hip arthroplasty (THA) dislocation. Differences in kinematics and kinetics at the hip during activities of daily living such as sit-to-stand (STS) may contribute to this risk. Nine high body mass index (BMI) subjects (mean BMI 31.2) and ten normal BMI control subjects (mean BMI 22.1) were analyzed using force plates and an optoelectronic motion capture camera system during controlled STS movement. Flexion/extension, abduction/adduction, and internal/external rotation angles and moments at the hip and knee were calculated using a musculoskeletal model. No differences were found at the knee. Peak hip abduction angles were on average 50% greater in the high BMI group compared to the normal group (p=0.038). The hip was roughly 50% more abducted throughout the entire STS cycle in the high BMI group. Peak normalized hip abduction moments were approximately twice as large in the high BMI group (p=0.005). Further research is required to determine if this increase in abduction angle and moment observed during STS is a contributor to risk for complications following THA in obese subjects.

LC-MS/MS identification of the one-carbon cycle metabolites in human plasma

The one‐carbon cycle is composed of four major biologically important molecules: methionine (l‐Met), S‐adenosylmethionine (SAM), S‐adenosylhomocysteine (SAH), and homocysteine (Hcy). In addition to these key metabolites, there are multiple enzymes, vitamins, and cofactors that play essential roles in the cascade of the biochemical reactions that convert one metabolite into another in the cycle. Simultaneous quantitative measurement of four major metabolites can be used to detect possible aberrations in this vital cycle. Abnormalities in the one‐carbon cycle might lead to hyper‐ or hypomethylation, homocystinemia, liver dysfunction, and accumulation of white‐matter hyperintensities in the human brain. Previously published methods describe evaluation of several components of the one‐carbon cycle, but none to our knowledge demonstrated simultaneous measurement of all four key molecules (l‐Met, SAM, SAH, and Hcy). We describe a novel analytical method suitable for simultaneous identification and quantification of l‐Met, SAM, SAH, and Hcy with LC‐MS/MS. Moreover, we tested this method to identify these metabolites in human plasma collected from patients with multiple sclerosis and healthy individuals. In a pilot feasibility study, our results indicate that patients with multiple sclerosis showed abnormalities in the one‐carbon cycle.

Diffuse Idiopathic Skeletal Hyperostosis Association With Thoracic Spine Kyphosis A Cross-sectional Study for the Health Aging and Body Composition Study

Study Design. A descriptive study of the association between diffuse idiopathic skeletal hyperostosis (DISH) and kyphosis. Objective. To investigate the association of DISH with Cobb angle of kyphosis in a large cohort of older subjects from the Health Aging and Body Composition Study. Summary of Background Data. DISH and thoracic kyphosis are well-defined radiographical findings in spines of older individuals. Characteristics of DISH (ossifications between vertebral segments) reflect changes of spine anatomy and physiology that may be associated with Cobb angle of kyphosis. Methods. Using data from 1172 subjects aged 70 to 79 years, we measured DISH and Cobb angle of kyphosis from computed tomographic lateral scout scans. Characteristics of participants with and without DISH were assessed using the &khgr;2 and t tests. Association between DISH and Cobb angle was analyzed using linear regression. Cobb angle and DISH relationship was assessed at different spine levels (thoracic and lumbar). Results. DISH was identified on computed tomographic scout scan in 152 subjects with 101 cases in only the thoracic spine and 51 in both thoracic and lumbar spine segments. The mean Cobb angle of kyphosis in the analytic sample was 31.3° (standard deviation = 11.2). The presence of DISH was associated with a greater Cobb angle of 9.1° and 95% confidence interval (95% CI) (5.6–12.6) among African Americans and a Cobb angle of 2.9° and 95% CI (0.5–5.2) among Caucasians compared with those with no DISH. DISH in the thoracic spine alone was associated with a greater Cobb angle of 10.6° and 95% CI (6.5–14.7) in African Americans and a Cobb angle of 3.8° and 95% CI (1.0–6.5) in Caucasians compared with those with no DISH. Conclusion. DISH is associated with greater Cobb angle of kyphosis, especially when present in the thoracic spine alone. The association of DISH with Cobb angle is stronger within the African American population. Level of Evidence: 3

HIP, KNEE AND ANKLE JOINT FORCES IN HEALTHY WEIGHT, OVERWEIGHT AND OBESE INDIVIDUALS DURING WALKING

Worldwide in 2008, more than 1.4 billion adults, age 20 and older, were overweight. Overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health. The World Health Organization defines overweight as having a body mass index (BMI) greater than or equal to 25 kg/m2 and obese as a BMI greater than or equal to 30 kg/m2. The aim of this study was to compare peak hip, knee, and ankle joint compressive loads during gait at self-selected speed between overweight and healthy weight individuals and to examine the functional relationship between body mass and peak joint forces. Twelve subjects, six high BMI subjects and six normal BMI control subjects, participated in this investigation. Absolute peak hip, knee, and ankle joint forces were 40 %, 43 %, and 48 % greater, respectively, for the high-BMI versus normal group. Joint loads were found to increase approximately linearly with body mass. Body mass accounted for 70–80 % of the variation in the peak compressive load at the hip, knee, and ankle during gait. These findings support the link that increased body mass leads to increased biomechanical loading of the joints and could be a factor linking obesity to osteoarthritis.

Assessing lower extremity coordination and coordination variability in individuals with anterior cruciate ligament reconstruction during walking

BACKGROUND Despite our knowledge of several biomechanical risk factors related to anterior cruciate ligament (ACL) injury, such as decreased knee flexion, increased knee abduction, and increased hip flexion, adduction and internal rotation during walking, jogging, and landing from a jump, the incidence of ACL tears remains high. Quantifying variability in the lower extremity provides a continuous measure of joint coordination and function that may elicit an additional aspect of ACL injury mechanisms. RESEARCH QUESTION The aim of this study was to assess joint coordination patterns and variability in individuals following ACL reconstruction (ACLR). METHODS Twenty participants with unilateral ACLR and twenty uninjured participants matched by sex and body mass index (BMI) walked over-ground at self-selected speed. Two force plates embedded in the walking platform recorded ground reaction forces (GRF), and a motion capture system collected kinematic data. Vector coding was used to describe coordination patterns and measure coordination variability in hip-knee and knee-ankle coupled motion. RESULTS Individuals with ACLR had greater variability in hip-knee coordination compared to their healthy counterparts for both the reconstructed and contralateral limbs. The individuals with ACLR also exhibited altered coordination patterns, one of which was characterized by constrained hip motion. SIGNIFICANCE These results are evidence that differences in joint coordination exist between individuals with and without ACLR, even after the former are cleared to return to sport. This new insight into coordinative function after ACLR may be useful for improving rehabilitation strategies as well as identifying those at risk of injury during return to sport testing.

Lower Limb Kinematics and Metabolic Cost During Elliptical Exercises and Treadmill Running

The purpose of this study was to compare knee and hip joint kinematics previously associated with anterior knee pain and metabolic cost among conditions including treadmill running (TR), standard elliptical (SE), and lateral elliptical (LE) in healthy runners. Joint kinematics and metabolic parameters of 16 runners were collected during all 3 modalities using motion capture and a metabolic system, respectively. Sagittal knee range of motion (ROM) was greater in LE (P < .001) and SE (P < .001) compared with TR. Frontal and transverse plane hip ROM were greater in LE compared with SE (P < .001) and TR (P < .001). Contralateral pelvic drop ROM was smaller in SE compared with TR (P = .002) and LE (P = .005). Similar oxygen consumption was found during LE and TR (P = .39), but LE (P < .001) and TR (P < .001) required greater oxygen consumption than SE. Although LE yields similar metabolic cost to TR and produces hip kinematics that may help strengthen hip abductors, greater knee flexion and abduction during LE may increase symptoms in runners with anterior knee pain. The findings suggest that research on the implications of elliptical exercise for injured runners is needed.