Papers by Tamara Scerpella
Pediatric Exercise Science
Purpose: We assessed maintenance of skeletal advantages 3 years after completion of a 2-year, sch... more Purpose: We assessed maintenance of skeletal advantages 3 years after completion of a 2-year, school-based, controlled exercise trial in adolescent girls. Method: Middle-school girls participated in a resistance training program embedded in physical education classes. Effort groups (low-effort group [LO] and high-effort group [HI]) were identified; the control group (CON) participated in standard physical education at a separate school. Baseline and follow-up (FU) assessments at 6, 18, and 54 (FU3) months included densitometry, anthropometry, and questionnaires assessing physical maturity and nonintervention organized physical activity. Linear mixed effects models were fit to evaluate bone outcomes across all FU time points for CON versus LO/HI. Results: Sixty-eight girls (23 CON/25 HI/20 LO) were 11.6 (0.3) years at baseline. Bone parameters did not differ at baseline, except femoral neck bone mineral density (LO < HI/CON, P < .05). Forty-seven participants provided FU3 asses...
The American Journal of Sports Medicine
Background: Osteoarthritis (OA) is a significant long term concern after anterior cruciate ligame... more Background: Osteoarthritis (OA) is a significant long term concern after anterior cruciate ligament (ACL) reconstruction (ACLR). A low bone mineral density (BMD), particularly in the subchondral region, has been associated with the development of OA and is evident at the knee in patients long after ACLR. It is unknown if persistent BMD deficits are present in high level collegiate athletes. Purpose/Hypothesis: The purpose of this study was to evaluate bilateral changes in the BMD of the femur and tibia from before the injury to 24 months after ACLR in collegiate athletes. We hypothesized that the BMD of both the distal femur and the proximal tibia would be significantly reduced within the surgical limb initially postoperatively but return to preinjury levels by 24 months after ACLR. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 33 Division I collegiate athletes were identified between 2010 and 2021 (13 female) who underwent total body dual-energy X-ray absorp...
BMC Musculoskeletal Disorders, 2022
Background Anterior cruciate ligament (ACL) rupture in humans is a common condition associated wi... more Background Anterior cruciate ligament (ACL) rupture in humans is a common condition associated with knee pain, joint instability, and secondary osteoarthritis (OA). Surgical treatment with an intraarticular graft provides reasonable outcomes at mid and long-term follow-up. Non-modifiable and modifiable factors influence risk of ACL rupture. The etiology, mechanobiology, causal biomechanics, and causal molecular pathways are not fully understood. The dog model has shared features of ACL rupture that make it a valuable spontaneous preclinical animal model. In this article, we review shared and contrasting features of ACL rupture in the two species and present information supporting spontaneous canine ACL rupture as a potentially useful preclinical model of human ACL rupture with a very large subject population. Results ACL rupture is more common in dogs than in humans and is diagnosed and treated using similar approaches to that of human patients. Development of OA occurs in both spec...
Journal of Musculoskeletal & Neuronal Interactions, 2015
Objectives: Youth exercise is associated with improved body composition, but details regarding ti... more Objectives: Youth exercise is associated with improved body composition, but details regarding timing and persistence are limited. We examined pre- and circum-menarcheal organized physical activity exposure (PA) as a factor in development of early post-menarcheal lean mass, fat mass and muscle strength. Methods: Participants in a longitudinal study of musculoskeletal growth using dual energy X-ray absorptiometry (DXA) were included based on: 1) Whole body DXA scans: 0.5-1.5 years pre-menarche, 0.5-1.5 years post-menarche; 2) PA records for ≥6 months preceding the first DXA (PREPA) and for the inter-DXA interval (CIRCUMPA). Dominant arm grip strength and sit-ups tests coincided with DXA scans; PA, height and maturity were recorded semi-annually. Regressions correlated PA with lean mass/fat mass/strength, accounting for maturity, body size, and baseline values. Results Seventy girls [baseline: 11.8 yrs (sd 1.0), follow-up: 13.9 years (sd 1.0)] demonstrated circum-menarcheal gains of 2...
Medicine & Science in Sports & Exercise, 2021
Exogenous hormone exposure in adolescence may affect lifetime fracture risk, as ~30% of bone mass... more Exogenous hormone exposure in adolescence may affect lifetime fracture risk, as ~30% of bone mass is accrued from menarche to peak bone mass. PURPOSE: We investigated associations of hormonal contraceptive (HC) use with bone accrual rates from circum-menarche (MEN) to peak bone mass (PBM) in gymnasts (GYM) and non-gymnasts (NON). METHODS: A 20-year prospective longitudinal study of bone accrual in GYM vs. NON yielded annual DXA data for bone mineral content (BMC) and areal bone mineral density (BMD) at key sites: 1/3 radius (1/3), ultra-distal radius (UD), lumbar spine (LS) and femoral neck (FN). A subset of data was analyzed to evaluate annualized BMC and BMD gains from MEN (-1.0 to +1.0 yrs post-menarche) to PBM (+4.0 to +6.67 yrs post-menarche). Inclusion criteria were ≥1 qualifying scan per site during each maturity stage (MEN & PBM) and self-reported data on HC use for the inter-scan interval. HC use from MEN to PBM was categorized as no HC use, ≤2 yrs HC use or >2 yrs HCuse...
Medicine & Science in Sports & Exercise, 2018
PURPOSE: To evaluate differences in objectively measured PA, overall and by time of day, between ... more PURPOSE: To evaluate differences in objectively measured PA, overall and by time of day, between younger and older adults. METHODS: Physical activity (PA) was measured using wrist-worn ActiGraph accelerometers continuously over 7 days in 58 older adults (50% women, aged 72±6 yrs) and 56 younger adults (54% women, age 21±2 yrs), and body composition was measured using dual energy x-ray absorptiometry. PA data was smoothed into one-minute intervals and expressed as the vector magnitude of counts (VMC) per minute across the three axes. Diurnal patterns of activity were modeled as the average VMC over six 4-hour time bins. Subjects were categorized by age group (young or old), and the association between the mean of the VMC and age group was modeled overall and across each time bin using linear regression, adjusting for sex, fat-free mass, and fat mass. RESULTS: Total 24-h PA was lower in older adults compared to younger adults (2.1x10±0.8x10 vs. 2.8x10±0.9x10 VMC, p < 0.0001). However, when examining diurnal patterns, early morning (4:00am8:00am) and morning (8:00am-noon) PA was higher in older adults compared to younger adults (p<0.001 for each period) in fully adjusted models. In the remaining time bins, younger adults had higher PA than older adults (p<0.01 for each period). CONCLUSION: Consistent with previous studies, total daily PA was lower in older adults compared to younger adults. Importantly, examining PA across the day highlighted significant differences in activity volumes between younger and older adults that provide evidence to inform future interventions to improve PA profiles in both younger and older individuals.
Medicine & Science in Sports & Exercise, 2020
2.1yr (sd 0.3) and +2.1yr (sd 0.3), respectively. For CIRCAPHV & POSTMEN comparisons, n=108, with... more 2.1yr (sd 0.3) and +2.1yr (sd 0.3), respectively. For CIRCAPHV & POSTMEN comparisons, n=108, with mean gynecological ages-1.1yr (sd 0.7) and +0.6yr (sd 0.3) and mean SITARMO-0.1yr (sd 0.4) and +1.6yr (sd 0.7), respectively. Except POSTMEN, on average, MO1 underestimated SITARMO [PREPHV-1.5yr, POSTPHV-2.8yr; CIRCAPHV=-2.3yr, POSTMEN= +0.5yr]. Mean discrepancies for MO2 vs. SITARMO were subtle, near zero [PREPHV= +0.4yr, POSTPHV= +0.1yr; CIRCAPHV=-0.1yr, POSTMEN=-0.01yr]. CONCLUSION: MO1 maturity estimates are flawed; <50% of estimates were within 1yr of SITARMO for assessed maturity ranges. MO2 provides better SITARMO estimates using cross-sectional data. However, it is unclear whether MO2 is an improvement over chronological age for most individuals, as MO2 effectively assesses whether girls are short or tall for their age. In many cases, height for age may primarily reflect genetic height potential rather than maturity status, particularly at older maturity stages. Supported by funding from NIH/NIAMS (R03 AR047613-03; R01 AR54145-5);
Journal of biomechanics, Jan 17, 2018
Mechanical loading through youth exercise is highly modifiable and represents a strategy to maxim... more Mechanical loading through youth exercise is highly modifiable and represents a strategy to maximize peak adult bone mass, with the potential for broad implementation across the population to lower fracture risk. For girls, circum-menarcheal growth is critical, with around 50% of adult bone acquired over a 4-year period. Here, we prospectively followed 10 gymnasts and 12 age-matched non-gymnasts across approximately 4 years circum-menarche. A combination of pQCT and subject-specific finite element models were used to measure differences in bone acquisition and structure between the groups, and to determine the degree to which specific mechanical factors predict change in bone structure. At baseline, gymnasts had stronger bone, including 26% higher BMC, 51% greater compressive strength, and 21% higher trabecular density. Over the study period, both groups more than doubled their bone strength. Pre-menarcheal principal stresses predicted change in pQCT variables for non-gymnasts, but ...
Orthopaedic journal of sports medicine, 2017
Recent evidence shows a delayed return to sport in children and delayed quadriceps recovery in bo... more Recent evidence shows a delayed return to sport in children and delayed quadriceps recovery in both adults and children who have undergone anterior cruciate ligament (ACL) reconstruction with concomitant femoral nerve blockade (FNB) compared with those who had no blockade. We evaluated the use of adductor canal blockade (ACB), as an alternative to FNB, at the time of ACL reconstruction. Patients who receive ACB will have greater isokinetic strength at 6 months postoperative compared with patients who receive FNB at the time of ACL reconstruction. Cohort study; Level of evidence, 3. A retrospective record review was performed at a single academic medical center to identify all patients aged ≥16 years who had undergone ACL reconstruction with blockade between January 2010 and January 2015. Exclusion criteria included (1) non-sports medicine fellowship-trained surgeon performing the procedure, (2) continuous nerve catheter or concurrent epidural used, (3) revision ACL reconstruction or...
Journal of Clinical Densitometry, 2017
Background-Consistency of DXA scan results is critical for data integrity. For pediatric subjects... more Background-Consistency of DXA scan results is critical for data integrity. For pediatric subjects, the extent to which cross-calibration of DXA scanners alleviates model to model scanner differences is unclear. In the current study, DXA bone outcomes were compared for same-day measurements performed using different scanners, cross-calibrated to alleviate discrepancies (Hologic: Discovery A (DISCO); QDR 4500W (QDR)). Methods-Inter-scanner differences were evaluated in approximately 130 females, age 8 to 24 years. Scans were performed in a single session on both QDR and DISCO scanners to compare projected area, bone mineral content (BMC), and areal bone mineral density (BMD) output for whole body (total, sub-head, head, arm, leg), forearm (1/3 and ultradistal radius), lumbar spine (vertebra L3; L1-L4) and proximal femur (femoral neck). Paired t-tests evaluated inter-scanner differences; concordance correlation coefficients evaluated inter-scanner correlations. Root mean square error coefficients of variation (RMSECVs) were compared to same-day duplicate DISCO scan RMSECVs for approximately 30 adult females. Deming regression equations were generated for conversion of QDR to DISCO results and vice versa. Results-Inter-scanner correlations were very high (95% CI for CCC > 0.90), for all outcomes except femoral neck area and sub-head area, (95% CI for CCC = 0.83 to 0.94; 0.57 to 073). However, QDR values were systematically lower than Discovery values (p < 0.05), except head area, head BMC, head BMD, ultradistal BMD (QDR > Discovery, p ≤ 0.05) and L1-L4 area, L3 area, femoral neck BMD (no differences). Most Bland-Altman and Deming regression plots indicated good inter-scanner agreement, with little systematic variation based on bone/body size.
The American Journal of Sports Medicine, 2003
Journal of musculoskeletal & neuronal interactions
This review addresses bone geometry and indices of skeletal strength associated with exposure to ... more This review addresses bone geometry and indices of skeletal strength associated with exposure to gymnastic loading during growth. A brief background characterizes artistic gymnastics as a mechanical loading model and outlines densitometric techniques, skeletal outcomes and challenges in assessment of skeletal adaptation. The literature on bone geometric adaptation to gymnastic loading is sparse and consists of results for disparate skeletal sites, maturity phases, gender compositions and assessment methods, complicating synthesis of an overriding view. Furthermore, most studies assess only females, with little information on males and adults. Nonetheless, gymnastic loading during growth appears to yield significant enlargement of total and cortical bone geometry (+10 to 30%) and elevation of trabecular density (+20%) in the forearm, yielding elevated indices of skeletal strength (+20 to +50%). Other sites exhibit more moderate geometric and densitometric adaptations (5 to 15%). Mode...
Journal of musculoskeletal & neuronal interactions
Muscular forces are an important determinant of bone strength, but bone may also adapt to non-mus... more Muscular forces are an important determinant of bone strength, but bone may also adapt to non-muscular loading. We tested the hypothesis that loads associated with childhood gymnastics yield high arm bone mass (BMC), bone size and bone strength, independent of arm lean mass (FFM) and muscle cross-sectional area (CSA). Total body DXA and distal radius pQCT scans were performed on 33 post-menarcheal girls (19 ex/gymnasts, 14 non-gymnasts). Physical activity and calcium intake were assessed by questionnaire. For the non-dominant arm, pQCT measured bone strength indices and bone CSA (total, cortical) (4%, 33% sites); DXA measured arm FFM, arm BMC and skull BMC. Multiple regression analyses assessed gymnastic exposure, arm FFM, gynecological age and stature as predictors of bone parameters. Bone outcomes at loaded upper extremity sites were 10-42% greater in ex/gymnasts than non-gymnasts. Gymnastic exposure remained a consistent, significant predictor of upper extremity skeletal paramete...
Osteoporosis International, 2010
Development of optimal skeletal strength should decrease adult bone fragility. Nongymnasts (NON) ... more Development of optimal skeletal strength should decrease adult bone fragility. Nongymnasts (NON) were compared with girls exposed to gymnastics during growth (EX/GYM), using peripheral quantitative computed tomography (pQCT) to evaluate postmenarcheal bone geometry, density, and strength. Pre-and perimenarcheal gymnastic loading yields advantages in indices of postmenarcheal bone geometry and skeletal strength. Introduction-Two prior studies using pQCT have reported bone density and size advantages in Tanner I/II gymnasts, but none describe gymnasts' bone properties later in adolescence. The current study used pQCT to evaluate whether girls exposed to gymnastics during late childhood growth and perimenarcheal growth exhibited greater indices of distal radius geometry, density, and skeletal strength. Methods-Postmenarcheal subjects underwent 4% and 33% distal radius pQCT scans, yielding: 1) vBMD and cross-sectional areas (CSA) (total bone, compartments); 2) polar strength-strain index; 3) index of structural strength in axial compression. Output was compared for EX/GYM vs. NON, adjusting for gynecological age and stature (maturity and body size), reporting means, standard errors, and significance. Results-Sixteen postmenarcheal EX/GYM (age 16.7 years; gynecological age 3.4 years) and 13 NON (age 16.2 years; gynecological age 3.6 years) were evaluated. At both diaphysis and metaphysis, EX/GYM exhibited greater CSA and bone strength indices than NON; EX/GYM exhibited 79% larger intramedullary CSA than NON (p<0.05). EX/GYM had significantly higher 4% trabecular vBMD; differences were not detected for 4% total vBMD and 33% cortical vBMD. Conclusions-Following pre-/perimenarcheal gymnastic exposure, relative to nongymnasts, postmenarcheal EX/GYM demonstrated greater indices of distal radius geometry and skeletal strength (metaphysis and diaphysis) with greater metaphyseal trabecular vBMD; larger intramedullary cavity size was particularly striking.
Osteoporosis International, 2010
Preliminary prospective, longitudinal results suggest that pre-menarcheal exposure to artistic gy... more Preliminary prospective, longitudinal results suggest that pre-menarcheal exposure to artistic gymnastics is associated with greater radius BMC, aBMD, and projected area throughout growth and into early adulthood, more than 4 years after activity cessation. Any loss of benefit associated with de-training appears to be temporary. Introduction-Mechanical loading may enhance bone accrual during growth, but prospective evidence of benefit retention is limited. This prospective, longitudinal cohort study tests whether gymnastics is linked to distal radius advantages during growth and four or more years posttraining cessation. Methods-Semi-annually, female ex/gymnasts and non-gymnasts underwent height and weight measurements; questionnaires assessed calcium intake, physical activity, and maturation. Annual dual energy X-ray absorptiometry scans (Hologic QDR 4500W) measured total body fat-free mass, skull areal density (aBMD), and bone mineral content (BMC); forearm scans measured ultradistal and 1/3 radius area, BMC, and aBMD. Analysis inclusion criteria were: (1) achievement of gynecological age >4 years and (2) for gymnasts, >2 years of pre-menarcheal training (>6 h/week), ceasing between 0.5 year pre-menarche and 1 year post-menarche. Hierarchical linear modeling (HLM v6.0) evaluated outcomes for ex/gymnasts versus nongymnasts; a slope/intercept discontinuity evaluated de-training effects. Results-Data from 14 non-gymnasts and six ex/gymnasts represented outcomes from 4 years pre-menarche to 9 years post-menarche. All adjusted distal radius parameters were higher in ex/ gymnasts than non-gymnasts (p<0.02). Ultradistal BMC, ultradistal aBMD, and 1/3 aBMD temporarily decreased with gymnastic cessation (p<0.04); ultradistal area, 1/3 area, and 1/3 BMC did not change significantly. Skull outcomes did not differ between groups or change with activity cessation. Conclusion-Gymnastic exposure during childhood and early puberty is associated with greater radius bone mass, size, and aBMD. Despite brief de-training losses in density and mass, significant skeletal benefits are manifested throughout growth and at least 4 years beyond activity cessation into early adulthood.
Medicine & Science in Sports & Exercise, 2014
Purpose-Muscle forces influence development of bone mass and structure, but dynamic loading via i... more Purpose-Muscle forces influence development of bone mass and structure, but dynamic loading via impact exercise is considered particularly osteogenic. We hypothesized that indices of local muscle function AND physical activity exposure would predict femoral neck structure in pre-menarcheal females. Methods-We tested this hypothesis in 76 healthy, pre-menarcheal girls (46 gymnasts, 30 nongymnasts). Height, weight, Tanner breast stage (TB) and prior year non-aquatic, organized physical activity (PAL) were recorded semi-annually. Hologic DXA scans (whole body, left femoral neck (FN)) yielded total body non-bone lean mass and bone outcomes, including narrow neck (NN) hip structural analysis data. Dynamometers assessed non-dominant hand grip (GR) and left hip flexion/extension indices. Parsimonious regression models tested the following as predictors of bone outcomes: local muscle function, PAL, gymnast status and lean mass, accounting for Tanner breast stage and height, as appropriate. Results-Hip flexion indices were significantly correlated with indices of femoral neck mass, density, structure and strength (p<0.05). However, entry of PAL, gymnast status and lean mass into regression models supplanted local muscle function explanatory value. In contrast, for many variables, the significant association of gymnast status persisted after accounting for physical maturity, body size/lean mass and PAL. For all skeletal indices except FNArea, NNwidth, NN endosteal diameter and NN buckling ratio, gymnast status was more strongly associated with bone outcomes than PAL.
Medicine & Science in Sports & Exercise, 2010
adiposity was measured with magnetic resonance imaging and muscle strength was expressed as the s... more adiposity was measured with magnetic resonance imaging and muscle strength was expressed as the sum of one-repetition maximum weight lifted during a leg curl, extension and press. RESULTS: In bivariate correlations, SM and CSA were positively related to femoral BMD, weight, fat mass, lean mass and abdominal subcutaneous fat (r's ranged from 0.42 to 0.92) and negatively related to age (r=-0.33) in women. In men, femoral BMD, weight, lean mass and strength correlated with SM and CSA (r's ranged from 0.28 to 0.90), (all p's < 0.05). Using stepwise regression in women, femoral BMD was the strongest predictor of SM (R2= 0.44) and CSA (R2= 0.86). Lean mass accounted for an additional 1% of the variance in CSA. In men, femoral BMD was the strongest predictor of SM (R2= 0.49) and CSA (R2= 0.82) and lean mass explained an additional 10% and 3% of the variance in SM and CSA, respectively. Since increased BMD may not protect against hip fracture, in a final model without BMD, increased lean mass independently predicted increased SM (R2= 0.22 in women, R2= 0.28 in men) and increased CSA (R2= 0.27 in both sexes). CONCLUSIONS: Increased body weight and femoral BMD were associated with greater SM and CSA among men and women. However, independent of femoral BMD, lean mass was a modest yet independent determinant of bone strength. These data suggest that interventions that increase lean muscle mass in T2DM may prove to be a useful strategy for fracture prevention.
Medicine & Science in Sports & Exercise, 2010
To verify the prevalence of the metabolic syndrome (MetS) in Brazilian overweight adolescents. ME... more To verify the prevalence of the metabolic syndrome (MetS) in Brazilian overweight adolescents. METHODS: A random sample of 236 girls (mean age, 14.5 ± 1.7 years) and 203 boys (mean age, 14.7±1.8 years) was selected for the study. Body mass index was calculated by weight /height2. BMI was classified using the NCHS growth charts. Abdominal obesity was considered as waist circumference ≥ 90th for age and gender. Hypertension was considered as having an average SBP or DBP> 90th by age and gender. Adolescents were considered to have excessive total triglyceride levels if blood concentrations were ≥ 110 mg/dL. HDL-C levels were considered low at a level of ≤ 40 mg/dL, while fasting blood glucose levels ≥ 110 mg/dL were considered indicative of hyperglycemia. MetS was diagnosed when three or more of the five individual elements were found together in the same individual. RESULTS: The general prevalence of MetS was 7.8% (males 9.4%; females 6.4%). The prevalence of MetS in overweight subjects (BMI ≥ 85th percentile) was 31.1% (42.4% in males; 22% in females). Overweight adolescents showed a higher chance to present MetS than normal weight adolescents (males:
European Journal of Clinical Nutrition, 2000
Diet and physical activity are two major lifestyle factors that play a role in the prevention or ... more Diet and physical activity are two major lifestyle factors that play a role in the prevention or management of debilitating conditions affecting older people. Both under-and overnutrition predispose to diseases. Low sodium and high potassium intakes, as well as the consumption of fruits and vegetables are associated with a reduction of hypertension and diseases arising from hypertension such as stroke and dementia. Dietary patterns (consumption of quantity and types of fats, cholesterol, vegetable oils, ®sh) are important in the prevention of coronary heart disease. Calcium and vitamin D intakes are important factors in the development of osteoporosis, while various dietary factors have been linked to the development of cancer. Physical activity is important in the prevention of functional decline and increased survival, reduced incidence of falls and fractures, and has various cardiovascular health bene®ts. Apart from prevention of diseases, exercise also has an important role in improving function in some chronic diseases such as heart failure or chronic obstructive pulmonary disease. Both diet and exercise interact, so that public health recommendations often take the form of lifestyle modi®cation advice in the prevention of disease and disability.
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Papers by Tamara Scerpella