Accelerometer-measured physical activity is associated with knee breadth in middle-aged Finns - a population-based study

Background: Articular surface size is traditionally considered to be a relatively stable trait throughout adulthood. Increased joint size reduces bone and cartilage tissue strains. Although physical activity (PA) has a clear association with diaphyseal morphology, the association between PA and articular surface size is yet to be confirmed. This cross-sectional study aimed to clarify the role of moderate-to-vigorous PA (MVPA) in knee morphology in terms of tibiofemoral joint size. Methods: A sample of 1508 individuals from the population-based Northern Finland Birth Cohort 1966 was used. At the age of 46, wrist-worn accelerometers were used to monitor MVPA (≥3.5 METs) during a period of two weeks, and knee radiographs were used to obtain three knee breadth measurements (femoral biepicondylar breadth, mediolateral breadth of femoral condyles, mediolateral breadth of the tibial plateau). The association between MVPA and knee breadth was analyzed using general linear models with adjustments for body mass index, smoking, education years, and accelerometer weartime. Results: Of the sample, 54.8% were women. Most individuals were non-smokers (54.6%) and had 9-12 years of education (69.6%). Mean body mass index was 26.2 (standard deviation 4.3) kg/m2. MVPA was uniformly associated with all three knee breadth measurements among both women and men. For each 60 minutes/day of MVPA, the knee breadth dimensions were 1.8-2.0% (or 1.26-1.42 mm) larger among women (p < 0.001) and 1.4-1.6% (or 1.21-1.28 mm) larger among men (p < 0.001). Conclusions: Higher MVPA is associated with larger tibiofemoral joint size. Our findings indicate that MVPA could potentially increase knee dimensions through similar biomechanical mechanisms it affects diaphyseal morphology, thus offering a potential target in reducing tissue strains and preventing knee problems. Further studies are needed to confirm and investigate the association between articulation area and musculoskeletal health.Peer reviewe

Physical activity, vertebral size and lumbar Modic changes in midlife

Abstract Physical activity (PA) influences bone tissue throughout the lifespan and is believed to have a positive effect on vertebral size also during adulthood, thus potentially improving vertebral strength and reducing fracture risk. Modic changes (MC), divided in three subgroups (MC1, MC2, MC3), are vertebral bone marrow changes visible in magnetic resonance imaging (MRI) that are associated with non-specific low back pain (LBP). This thesis includes three population-based cohort studies (I, II, III) which aim was to investigate the association between device-measured moderate to vigorous intensity PA (MVPA, ≥ 3.5 METs), vertebral cross-sectional area (CSA) (I), and lumbar MC (II), and to determine the relationship between vertebral dimensions and lumbar MC (III), using a subsample (n = 1202–1374) of the Northern Finland Birth Cohort 1966. Participants aged 46 to 48 underwent lumbar MRI from which vertebral dimensions and lumbar MC were assessed, and their daily MVPA was determined by a wrist-worn activity monitor. The results showed that MVPA was positively associated with vertebral CSA among both sexes. Among men, a higher amount of MVPA was associated with increased odds of any lumbar MC, particularly MC2, whereas among women no such association was found. Exploration of the relationship between vertebral dimensions and lumbar MC revealed that vertebral height was positively associated with the presence of lumbar MC2, whereas vertebral CSA and volume were not associated with MC. The results of this thesis propose that MVPA has a positive impact on vertebral size among both sexes at midlife, thus lifelong MVPA might be a preventive action for reducing future vertebral fractures. Lumbar MC seem to be associated with higher vertebrae. MVPA seems to be associated with an increased likelihood of lumbar MC, but only among men and especially with MC2, strengthening the hypothesis that changed mechanical conditions due to hyperloading are connected to MC2. Further studies are needed to verify these findings and to clarify their clinical importance. For more profound comprehension, the significance of total daily PA and sedentary time should also be investigated.Tiivistelmä Alaselkäkipu on yleisin työikäisten toimintakykyä heikentävä sairaus, ja nikamamurtumat ovat merkittävä ikääntyvän väestön liikuntakykyä ja elämänlaatua heikentävä tekijä maailmanlaajuisesti. Fyysinen aktiivisuus vaikuttaa luustoon läpi elämän, ja sillä on mahdollisesti positiivinen vaikutus nikaman kokoon vielä aikuisiässäkin vahvistaen nikamaa ja ennaltaehkäisten murtumia. Modic-muutokset (MC:t, alaryhmät MC1, MC2, MC3) ovat magneettikuvauksessa nähtäviä selkänikamien luuydinmuutoksia, jotka ovat yhteydessä pitkittyneeseen alaselkäkipuun. Väitöstutkimuksen (osatyöt I, II, III) tavoitteena oli selvittää kiihtyvyysanturiin perustuvalla ranteessa pidettävällä aktiivisuusmittarilla mitatun vähintään kohtuullisesti kuormittavan fyysisen aktiivisuuden (≥ 3.5 METs) yhteyttä nikaman poikkipinta-alaan (I) ja lannerangan MC:n riskiin (II). Lisäksi selvitettiin nikaman koon ja MC:n välistä yhteyttä (III). Tutkimusaineistona oli väestöpohjainen Pohjois-Suomen syntymäkohortti 1966. Tutkittavien (n = 1202–1374) ollessa 46–48-vuotiaita, he osallistuivat fyysisen aktiivisuuden mittauksiin ja lannerangan magneettikuvaukseen. Tulokset osoittivat, että vähintään kohtuullisesti kuormittava fyysinen aktiivisuus oli positiivisesti yhteydessä nikaman poikkipinta-alaan molemmilla sukupuolilla. Miehillä suurempi määrä päivittäistä vähintään kohtuukuormitteista fyysistä aktiivisuutta oli positiivisesti yhteydessä lannerangan MC:n, erityisesti MC2:n, naisilla yhteyttä ei havaittu. Nikaman korkeus oli positiivisesti yhteydessä lannerangan MC2:n, nikaman poikkipinta-ala ja tilavuus eivät sen sijaan olleet yhteydessä MC:n. Tutkimustulosten perusteella voidaan todeta, että vähintään kohtuukuormitteisella fyysisellä aktiivisuudella on positiivinen vaikutus nikaman kokoon keski-iässä molemmilla sukupuolilla ja sitä voidaan pitää yhtenä varteenotettavana nikamamurtumien ennaltaehkäisykeinona. Lannerangan MC:t saattavat olla yhteydessä korkeampaan nikamaan, ja miehillä vähintään kohtuukuormitteinen fyysinen aktiivisuus näyttäisi olevan yhteydessä lannerangan MC2:n suurempaan todennäköisyyteen vahvistaen teoriaa mekaanisen ylikuormituksen ja MC2:n yhteydestä. Tulosten vahvistamiseksi tarvitaan lisää tutkimuksia, jotta voidaan kehittää täsmällisempiä ja tehokkaampia menetelmiä selkäsairauksien ennaltaehkäisyyn ja hoitoon sekä väestön työ- ja toimintakyvyn ja hyvinvoinnin edistämiseen

Accelerometer-measured physical activity is associated with knee breadth in middle-aged Finns:a population-based study

Abstract Background: Articular surface size is traditionally considered to be a relatively stable trait throughout adulthood. Increased joint size reduces bone and cartilage tissue strains. Although physical activity (PA) has a clear association with diaphyseal morphology, the association between PA and articular surface size is yet to be confirmed. This cross-sectional study aimed to clarify the role of moderate-to-vigorous PA (MVPA) in knee morphology in terms of tibiofemoral joint size. Methods: A sample of 1508 individuals from the population-based Northern Finland Birth Cohort 1966 was used. At the age of 46, wrist-worn accelerometers were used to monitor MVPA (≥3.5 METs) during a period of two weeks, and knee radiographs were used to obtain three knee breadth measurements (femoral biepicondylar breadth, mediolateral breadth of femoral condyles, mediolateral breadth of the tibial plateau). The association between MVPA and knee breadth was analyzed using general linear models with adjustments for body mass index, smoking, education years, and accelerometer weartime. Results: Of the sample, 54.8% were women. Most individuals were non-smokers (54.6%) and had 9—12 years of education (69.6%). Mean body mass index was 26.2 (standard deviation 4.3) kg/m2. MVPA was uniformly associated with all three knee breadth measurements among both women and men. For each 60 minutes/day of MVPA, the knee breadth dimensions were 1.8—2.0% (or 1.26—1.42 mm) larger among women (p &lt; 0.001) and 1.4—1.6% (or 1.21—1.28 mm) larger among men (p &lt; 0.001). Conclusions: Higher MVPA is associated with larger tibiofemoral joint size. Our findings indicate that MVPA could potentially increase knee dimensions through similar biomechanical mechanisms it affects diaphyseal morphology, thus offering a potential target in reducing tissue strains and preventing knee problems. Further studies are needed to confirm and investigate the association between articulation area and musculoskeletal health

Association between device-measured physical activity and lumbar Modic changes

Abstract Background: Modic changes (MC) in the lumbar spine are considered one potential etiological factor behind low back pain (LBP). Multiple risk factors for MC have been suggested, including male gender, smoking and factors affecting hyperloading and mechanical stress such as high body mass index (BMI), strenuous physical work and high occupational and leisure-time physical activity (PA). So far, the effect of PA on the occurrence of MC has remained under debate due to contradictory findings. The purpose of this study was to investigate the possible association between device-measured moderate-to-vigorous PA (MVPA) (≥ 3.5 METs) and lumbar MC. Methods: The study had 1374 participants from the Northern Finland Birth Cohort 1966. At the age of 46–48, PA was measured by a wrist-worn accelerometer, and lumbar magnetic resonance imaging (MRI) was carried out to determine MC. We analyzed the association between Type 1 (MC1) and Type 2 (MC2) MC and daily amount of MVPA (min/day) using sex-stratified logistic regression models before and after adjustment for BMI, socioeconomic status, smoking, and accelerometer wear time. Results: Among men, increased amount of MVPA was positively associated with any MC (adjusted OR corresponding to every 60 min/day of MVPA 1.41; 95% confidence interval (CI) 1.01 to 1.95) and MC2 (OR 1.54; 95% CI 1.14 to 2.08), but not with MC1 (OR 1.06; 95% CI 0.80 to 1.39). Among women, we only found a positive association between MVPA and MC1 before adjustments (unadjusted OR 1.42; 95% CI 1.06 to 1.92). Conclusions: Among men, increased amount of MVPA was associated with increased odds of any MC and particularly MC2. Among women, MVPA was not independently associated with MC

Association between vertebral dimensions and lumbar Modic changes

Abstract Study Design: Population-based birth cohort study. Objective: The aim of this study was to evaluate the relationship between vertebral dimensions and lumbar MC. Summary of Background Data: Low back pain (LBP) has become the leading cause of disability worldwide. Modic changes (MC) of the lumbar spine are one potential LBP-associated etiological factor. Mechanical stress is considered to play a key role in the development of MC through damage to endplates. There is speculation that vertebral dimensions play a role in some degenerative changes in the spine. Previous studies have also shown a positive association between moderate-to-vigorous physical activity (MVPA) and both vertebral dimensions and MC. In this study, we aimed to evaluate the relationship between vertebral dimensions and MC. Methods: The study population consisted of 1221 participants from the Northern Finland Birth Cohort 1966 who underwent lumbar magnetic resonance imaging (MRI) and physical activity measurements at the age of 46–48. The presence of Type 1 (MC1) and Type 2 (MC2) MC and the height, axial cross-sectional area (CSA), and volume of the L4 vertebra were determined from MRI scans. MVPA (≥3.5 metabolic equivalents) was measured by a wrist-worn accelerometer. We analyzed the association between lumbar MC and vertebral height, CSA, and volume using logistic regression models before and after adjustment for sex, height, weight, smoking, education level, and MVPA. Results: Vertebral height was positively associated with the presence of MC2 (odds ratio [OR] 3.51; 95% confidence interval [CI] 1.43–8.65), whereas vertebral CSA was not associated with the presence of lumbar MC. Vertebral volume was positively associated with the presence of any MC (OR 1.04; 95% CI 1.00–1.07), but the association did not persist when analyzing MC1 and MC2 separately. Conclusions: Vertebral height was associated with the presence of MC2. Further studies are needed to clarify the role of vertebral dimensions as independent risk factors for MC