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Inquiry Article

Ranking of osteogenic potential of physical exercises in postmenopausal women based on femoral cervix strains

• Pim Pellikaan,
• Georgios Giarmatzis,
• Jos Vander Sloten,
• Sabine Verschueren,
• Ilse Jonkers

x

• Published: Apr 4, 2018
• https://doi.org/x.1371/journal.pone.0195463

Figures

Abstruse

The electric current study aimed to assess the potential of different exercises triggering an osteogenic response at the femoral neck in a group of postmenopausal women. The osteogenic potential was determined by ranking the peak hip contact forces (HCFs) and consequent superlative tensile and compressive strains at the superior and junior part of the femoral neck during activities such equally (fast) walking, running and resistance training exercises. Results indicate that fast walking (v–6 km/h) running and hopping induced significantly higher strains at the femoral cervix than walking at 4 km/h which is considered a baseline practise for bone preservation. Exercises with a loftier fracture risk such every bit hopping, need to be considered carefully especially in a fragile elderly population and may therefore not be suitable as a preparation exercise. Since superior femoral neck frailness is related to elevated hip fracture risk, exercises such as fast walking (above v km/h) and running can be highly recommended to stimulate this particular area. Our results suggest that a grooming program including fast walking (above 5 km/h) and running exercises may increase or preserve the bone mineral density (BMD) at the femoral neck.

Citation: Pellikaan P, Giarmatzis Grand, Vander Sloten J, Verschueren South, Jonkers I (2018) Ranking of osteogenic potential of physical exercises in postmenopausal women based on femoral neck strains. PLoS 1 13(4): e0195463. https://doi.org/ten.1371/journal.pone.0195463

Editor: Jose Manuel Garcia Aznar, Academy of Zaragoza, Espana

Received: December 6, 2017; Accustomed: March 22, 2018; Published: April 4, 2018

Copyright: © 2018 Pellikaan et al. This is an open access commodity distributed nether the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are inside the newspaper and its Supporting Information file.

Funding: This study was supported past grant G0526512 from the Fund for Scientific Enquiry (FWO-Vlaanderen www.fwo.be) to Due south. Verschueren and past the funding of Materialise NV through the Materialise chair for patient-specific biomechanics (www.materialise.com). The funders had no role in report pattern, data collection and analysis, decision to publish, or grooming of the manuscript.

Competing interests: The authors take declared that no competing interests be.

Introduction

Osteoporosis constitutes a major public health threat, affecting 27.6 1000000 men and women in EU27 in 2010 [1], manifested past bone fractures with an estimated treatment cost up to 37 billion euros. Hip fractures are the most predominant amidst all osteoporotic-related fractures with the highest morbidity rates [2] in the elderly population. Femoral neck fractures make up approximately twoscore% - 50% of all hip fractures and occur about three times more ofttimes in woman, underlining the sensitivity of this specific region. Exercise interventions such as (brisk) walking are known to increase bone density and strength at the femoral neck, however the osteogenic potential of this specific region during exercise has withal to exist adamant.

It is well established and first described by Julius Wolff in 1892 [3] that bone adapts its microstructure to its external mechanical surround. Based on this hypothesis, Frost [4] adult a mathematical clarification of os adaptation, also known as the mechanostat theory. In this theory, information technology is stated that os deforms as a issue of mechanical loading expressed in compressive or tensile strains triggering an osteogenic bone response that is regulated by electrochemical signals within the osteocytes network and the extracellular fluid when a certain threshold is reached [5]. Although this threshold value is proposed at around 1500 με [4], this applies simply to long mammalian basic and varies betwixt specific bone sites, and is affected by both site-specific loading history and characteristics such as rate, book and frequency [6,vii]. Both tensile or compression strains were considered as equally osteogenic, as they both activate osteogenic stalk cells in the bone matrix [8]. Various theoretical and numerical approaches have been developed in the recent decades to model this bone remodeling procedure driven by mechanical stimuli such as stress, strain and strain energy density [9–11]. Micro damage in the os matrix, disuse and overloading of the bone are also idea to play an of import role in its adaptive response [4].

Thus, further research should aim at identifying the optimal mechanical loading of the bone during general or specific exercises, given the different contact load and muscle forces acting on it. In this respect, specific exercises were establish to affect the bone mineral density (BMD) distribution by loading specific bone regions. Due to their loftier impact profile, weight-bearing exercises, such as brisk walking (v–6 km/h), running and jumping, have been plant to increase femoral neck BMD in postmenopausal women [12,13]. Instead, habitual walking (~four km/h [xiv]) is non associated with BMD changes in the femoral cervix of the elderly [fifteen] and tin therefore be considered as a baseline practise for os preservation [eleven,15,16]. Moreover, resistance exercises seem to moderately ameliorate hip BMD when they are hip-targeted and at high intensity [17,18], such equally 75–80% of the weight that tin can be lifted at once (1 repetition maximum). The main driving forcefulness behind the changes in BMD are the strain differences at the femoral neck during loading triggering local bone accommodation processes. However, these strains cannot be measured straight due to the invasiveness of the bachelor techniques.

Finite element (FE) assay combined with loading conditions calculated using musculoskeletal models is a non-invasive technique to summate the strain distribution at specific bone regions under diverse loading weather during several exercises. At present, no report assessed the maximum strains in the femoral neck during specific concrete exercises to evaluate their bone remodeling potential. Meanwhile, a strain energy criterion introduced by Huiskes et al [11] has been used by Martelli et al [16] to verify if normal walking, weight-bearing and resistance preparation exercises can trigger an osteogenic consequence in the femoral cervix. However, all of the weight-begetting exercises included in this written report were only performed past two young females instead of a group of elderly people and literature data was used to simulate the resistance grooming exercises based on joint torque information at specific angles.

The aim of this study was to evaluate the bone remodeling potential at the femoral neck during various exercises in an elderly study population. Superlative tensile and compressive strains were compared and ranked to the strains observed during habitual walking at 4 km/h which is considered as a baseline exercise for bone preservation [eleven,15,16].

Methods

Data from 14 mail-menopausal elderly women (63.9 ± seven years old) recruited among the local customs was collected during several physical activities in three split sessions as approved by the local Ideals Committee of UZ/KU Leuven (OG032/ ML10444 (s56405)). Post-menopausal woman are the main target group for most grooming programs that address osteoporosis. Participants with prior conditions that might limit their functional condition such equally pain, lower limb fractures or fractures were excluded from the study. A written informed consent was given by all participants. Firstly participants were asked to walk and run on a separate-belt treadmill (Forcelink, Culemborg, Holland) from iii km/h until their highest accessible speed with a cocky-selected transition speed from walking to running. Whereas all fourteen subjects walked at three–iv km/h, only vii subjects reached a walking speed of 6 km/h. Running was more than demanding; 4 subjects ran at five km/h, 8 subjects at vii km/h and only five reached the highest running speed of ix km/h. Footing reaction forces were recorded through embedded strength plates in the treadmill at one thousand Hz and filtered at 6 Hz. More details can be found in Giarmatzis et al. 2017[19].

Secondly, participants were asked to perform a hopping exercise consisting of three consecutive unilateral jumps on the force plate (AMTI OR6 Series, Watertown, MA, USA) separated in a landing and propulsion phase. Basis reaction forces were recorded at 1000 Hz and filtered at 100 Hz. Standard sport footwear was provided in both experiments.

Thirdly, 12 out of 14 subjects performed a dynamic hip abduction (HABD)/adduction (HADD) and flexion (HF)/extension (HE) practise in standing position while keeping their right leg straight, against an external weight equal to 40, 60 and eighty% of the 1 repetition maximum (RM) of the maximal lifted weight based on the guidelines from Chocolate-brown and Weir [20].

During all exercises, the kinematics were captured using a ten-camera VICON system (10–15 MX camera system, VICON, Oxford Metrics, Oxford, United kingdom) sampled at 100 Hz with an identical marker set [21] (Fig 1).

Fig ane. Mark set.

Reflective markers were placed on os anatomical landmarks of the body. Cluster markers were placed on the upper and lower leg for ameliorate motion tracking for these specific torso segments. During walking, running and hopping the medial markers of the knee and ankle were removed to avert whatever adaptation of the natural movement in case of marking contact.

https://doi.org/10.1371/journal.pone.0195463.g001

Musculoskeletal modeling

A full trunk generic musculoskeletal model developed by Hamner et al [22] consisting of 12 segments, 29 degrees of freedom (DOF) and 92 Hill-type musculotendon actuators was used. The knee was modeled as a sliding hinge joint, and the ankle as a revolute joint, both presenting one DOF, whereas the hip was modelled as a ball and socket joint with 3 DOF. Each model was scaled to friction match the discipline'south anthropometric characteristics based on mark data of anatomical landmarks at the hip, knee and ankle during a static trial. Joint angles were calculated using a Kalman smoothing algorithm[23] and musculus forces past static optimization, minimizing the squared sum of all muscle activations. Using a joint reaction analysis, hip and knee contact forces (HCFs and KCFs) were calculated and expressed in the local femur's coordinate organisation [24]. Muscle attachment locations and force directions were adamant using a dedicated Opensim plugin [25].

Finite element analysis (FEA)

A finite element model of the femur was constructed in Abaqus (Abaqus six.14–1, Dassault Systèmes Corp., Providence, RI, U.s.a.) identical to the geometry used in the musculoskeletal model. The femur's geometry was re-meshed to create a volume mesh of 353111 C3D4 tetrahedral elements with a global edge length of one.5 mm using the Mimics Innovation Suite (Materialise NV, Leuven, Belgium) and Patran (MSC software, Newport Beach, Ca, The states). The edge length was set based on a mesh sensitivity analysis of the maximal stress, strain and strain energy density in the femoral neck region. Hounsfield Units (HU) were adamant based on a Femur CT of a healthy 60 year old male with a slice thickness of 1.5 mm and a resolution of 512 by 512 pixels (px) with a size of 0.98mm segmented using the Mimics Innovation Suite (Materialise NV, Leuven, Belgium). The HU'due south of the femur CT were used as template and divided in 20 textile zones. A linear relation between the HU and bone density equally proposed by Bitsakos et al. [26] and Vahdati et al.[27] was assumed and the material backdrop were assigned to the geometry of the musculoskeletal model using warping techniques that deformed the volume mesh of the musculoskeletal femur geometry to match the geometry of the CT template before assigning the material backdrop. A material relation defined by Morgan et al. [28] was used to relate the bone mineral density of each material zone to their Young'south Modulus (1400–17500 MPa). The Poisson ratio was set up to 0.32 for bone densities above one.2 k/cc and 0.2 for os densities below ane.two g/cc [29].

The location of 26 muscles attachment sites from the generic musculoskeletal model were projected to their closest node point (2.8±1.6mm) on the surface mesh of the Atomic number 26 femur. The pre-defined OpenSim scale factor was used to uniformly scale the volume mesh to each subject field's anthropometry with the femoral head as origin. The muscle parts (#) included in the model were: Gluteus Minimus (3), Medius (3) and Maximus (3), Biceps Femoris Short Caput (i), Adductor Longus (i), Brevis (1) and Magnus (3), Pectineus (1), Iliacus (one), Psoas (1), Quadriceps Femoris (i), Gemellus (1), Periformis (1), Vastus Lateralis (1), Medialis (1) and Intermedius (1) and the Gastrocnemius Medialis (one) and Lateralis (ane).

Physiological boundary conditions were applied at the heart of the femoral head and knee centrality and coupled to the surface nodes at the femoral head and lateral and medial condyles respectively like to Speirs et al. [30]: Boundary conditions were constrained in such a way that the center of the femoral head could merely deflect in the direction of the knee axis center without constraining the rotational degrees of freedom. The genu axis was constrained in all directions.

In case of walking, loading conditions at 5 event time instances including the kickoff and 2nd pinnacle HCF were determined during a gait cycle and applied to the Fe model, including the calculated muscle and joint contact forces. The peak HCF during initial and terminal double support phase, are referred to as the first and second pinnacle of walking. In case of running, loading conditions at 3 consequence time instances including the peak HCF were determined to adequately represent the complete gait cycle. The representative gait or running bicycle was selected using the least root mean foursquare error between the HCF bend of each cycle and the boilerplate HCF bend of all cycles for each subject field and speed. During hopping and resistance grooming exercises, the instance of subject-specific peak HCF was selected as the just loading status. For each loading condition the calculated muscle forces were practical to the projected muscle attachment point and distributed over the closest neighboring node points. The hip contact forces were practical to the centre of the femoral head and distributed over the femoral caput equally was washed for the boundary weather.

The superior and inferior role of the femoral neck were analyzed separately as both parts accept dissimilar bone density distributions and fracture susceptibility, with the superior office being more brittle [31,32]. Therefore, peak tensile (maximal) and compressive (minimal) logarithmic chief strains were calculated at the superior and inferior function of the femoral neck to place exercises that peculiarly load these areas of the femoral neck. To practice then, the femoral neck was divided in a superior and inferior part forth the centrality of the femoral neck by determining the anterior/posterior axis using the cross product between femoral cervix and the y-axis adamant by the ISB local coordinate system of femur [33] and the superior/ inferior axis defined past the cross production of the anterior/posterior and femoral cervix axis. In absence of in-vivo strain measurements of the femoral neck, the hateful femoral head displacements are reported for comparison with Taylor et al. [34], therefore allowing indirect validation of the model response.

Statistics

The superlative hip contact forcefulness and strain in the inferior and superior office of the femoral cervix was calculated and averaged for each bailiwick and exercise (S1 Table). The Anscombe variance stabilizing transformation was applied to transform the data into an approximately standard Gaussian distribution. Linear mixed models were constructed with the practise as a fixed-outcome and the variability as a random intercept to business relationship for differences betwixt subjects. These models were used to compare the pinnacle hip contact force and strain for the inferior and superior office of the femoral neck for all exercises. For each linear mixed model a marginal ANOVA examination was performed to test the global effect of the exercises on the acme hip contact strength and principle strains.

Walking at 7 km/h was excluded from the analysis given the subject sample for that speed was limited to 2.

Results

Exercises were ranked with respect to the averaged peak HCFs (Fig 2) and the resulting femoral head displacement (Fig three), peak tensile and compressive principal strains, calculated for the junior and the superior part of the femoral neck (Figs iv–7 respectively). Exercises with a significant difference (p < .05) compared to habitual walking at 4 km/h (first peak) were marked with an asterisk. The estimates, lower/upper limits and p-values too equally the results from the ANOVA test for each linear mixed model were reported [S1 Tabular array].

Fig ii. Ranking hip contact forces.

Average meridian HCFs expressed in body weight of each field of study [BW] ranked from left to correct for the highest (blue) to the lowest HCF'southward (ruby). Asterisks denote the exercises with significantly unlike peak HCFs compared to walking at four km/h (1^st peak) indicated past the horizontal line.

https://doi.org/10.1371/journal.pone.0195463.g002

Fig 5. Ranking tensile strains inferior function.

Average peak tensile strains in μstrains (εμ) in the junior part of the femoral neck ranked from left to right for the highest (blue) to the everyman strain (red). Asterisks announce the exercises with significantly dissimilar peak tensile strains compared to walking at iv km/h (one^st elevation) indicated by the horizontal line.

https://doi.org/10.1371/journal.pone.0195463.g005

Fig 6. Ranking tensile strains superior role.

Average peak tensile strains in μstrains (εμ) in the superior part of the femoral neck ranked from left to correct for the highest (blue) to the everyman strain (ruby-red). Asterisks denote the exercises with significantly unlike peak tensile strains compared to walking at 4 km/h (1^st height) indicated by the horizontal line.

https://doi.org/ten.1371/journal.pone.0195463.g006

Fig 7. Compressive strains.

Compression strains at the proximal femur for (A) hopping (propulsion), (B) walking 6 km/h (second peak), (C) walking four km/h (showtime peak) and (D) Hip Abduction at 80% RM.

https://doi.org/10.1371/journal.pone.0195463.g007

Hip contact forces

The propulsion phase of hopping imposed the highest peak HCFs (seven.57 Body weight (BW)) amongst all exercises, followed past running vii km/h (6.eighteen BW), hopping landing phase (6.13 BW), running (8–9 km/h, 5.80 and 6.02 BW respectively) and fast walking (5–6 km/h, iv.55 and v.38 BW, respectively). Compared to normal walking at 4–5 km/h (3.82 BW and four.54BW respectively) resistance grooming exercises loaded the hip less, except for hip abduction at threescore% (3.55 BW) and 80% (4.eighteen BW) of RM, where the HCFs were similar. Overall tiptop HCFs ranged from 1 BW (hip adduction at forty% 1RM) to 7.57 BW (hop–propulsion) (Fig 2).

Femoral head displacement

Femoral head displacement during tiptop load ranged from i.51 to two.92 mm during walking and from 2.57 to four.36 for running (Fig 3). The highest deflection was constitute during hopping with a displacement equal to 3.78 and 6.29 mm during landing and propulsion respectively. The average displacement for the resistance exercises were 0.10, 0.74, 1.38 and 1.60 mm for respectively hip adduction, flexion, extension and abduction.

Pinnacle tensile strains

At the inferior function of the femoral neck, hopping induced the highest tensile strains, during propulsion (10373 με) and landing (9517 με) (Fig 4). Also running and fast walking imposed higher tensile strains ranging from 1616 με for the first peak of walking at five km/h to 3089 με for the 2nd peak of walking at vi km/h compared to the first elevation of walking at iv km/h (1474 με). All resistance preparation exercises except for hip abduction at eighty% RM (1480 με) induce lower strain values. Overall, acme tensile strains at the junior function of the femoral neck ranged from 284 με (hip adduction at twoscore% RM) to 10373 με (hopping–propulsion) (Fig 5). For the superior part of the femoral neck the highest tensile strain was found for walking at half-dozen km/h (2d peak– 5885 με) followed by running at ix, 7and viii km/h (5415, 4717 and 4673 με, respectively) (Fig vi). Notably, all resistance exercises induced lower tensile strain magnitudes compared to normal walking at iv km/h. Overall, tiptop tensile principal strains at the superior part of the femoral neck ranged from 450 με (hip adduction at 40% RM) to 5885 με (vi km/h walking–second peak). In most exercises, tensile strains at the superior part were college than in the inferior part except for hopping landing and propulsion (239% and 230%).

Peak compressive strains

At the inferior office of the femoral cervix, propulsion phase of hopping (-10304 με) induced the highest compressive strains, followed by the 2d peak during walking at 6 km/h (-8644 με) (Fig 7). The compressive strain magnitudes for all resistance training exercises are lower compared to habitual walking at 4 km/h. Overall, meridian compressive strains at the inferior part of the femoral cervix range from -887 με (hip adduction at 40% RM) to -10304 (hopping–propulsion) (Fig 8). Hence, the superior part of the femoral neck is by and large compressed by fast walking (second summit) and hopping. The highest compressive strain was induced by the 2nd pinnacle during walking at 6 km/h (-3602 με), followed by hopping–propulsion (-3458 με), second peak of walking at five km/h (-2906 με) and running at 9 km/h (-2552 με) (Fig 9). Overall, peak compressive principal strains at the superior function of the femoral neck range from -377 με (hip adduction at xl% RM) to -3602 με. For all exercises, compressive strains at the inferior office were higher than in the superior office.

Fig 8. Ranking compression strains inferior part.

Boilerplate peak compressive strains in μstrains (εμ) in the inferior function of the femoral neck ranked from left to right for the highest (blue) to the everyman strain (cherry). Asterisks announce the exercises with significantly different elevation compressive strains compared to walking at four km/h (1^st peak) indicated by the horizontal line.

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Fig nine. Ranking pinch strains superior part.

Average peak compressive strains in μstrains (εμ) in the due south function of the femoral neck ranked from left to right for the highest (blue) to the lowest strain (ruby). Asterisks denote the exercises with significantly different peak compressive strains compared to walking at iv km/h (1^st meridian) indicated past the horizontal line.

https://doi.org/10.1371/periodical.pone.0195463.g009

Give-and-take

The electric current report aimed to assess the osteogenic potential at the femoral neck for different exercises by calculating and comparison summit compressive and tensile strains occurring at the inferior and superior part of the femoral neck in a group of postmenopausal women. Hopping, running and fast walking for most speeds results in significantly higher compressive and tensile strains at the femoral neck compared to walking at four km/h, peradventure triggering an osteogenic effect at this particular area (Table ane).

Lack of in vivo strain data at the femoral neck during the exercises prohibits a straight comparing with the obtained strain results. However, the calculated femoral head displacements at meridian hip loading during walking are modest enough (< 3 mm) to be considered physiological [34,35] and can therefore serve equally an indirect validation of the strains calculated in our study [30].

Non all exercises imposed significantly college strains at the femoral neck than four km/h walking (Table 1), whereby mostly the resistance preparation exercises scored lower. Of all exercises tested in the report, hopping (landing and propulsion) resulted in the highest compressive and tensile strains at the junior part of the femoral neck. Fast walking (5–vi km/h, 2^nd peak) resulted in college compressive strains at the inferior and superior part and higher tensile strains at the superior femoral neck compared to walking at 4 km/h (ane^st tiptop). However, only resistance training exercises at 80% RM induced like strains at the femoral neck. At lower intensities than 80% RM the resistance training exercises induce significantly lower strains at the femoral neck compared to walking at 4 km/h (1^st tiptop). These results are partly in agreement with several clinical trials that suggest that a fast walking intervention program [xiii,36,37] and hopping (vertical/multidirectional) [38–xl] can induce an increment in the femoral cervix BMD in an elderly populations. Hence, in contradiction with previous studies [41,42] our results suggest no, or fifty-fifty a negative, effect of hip targeted resistance training exercises on the femoral neck BMD, except at intensities higher up 80% RM. Therefore these exercises alone seem to be unsuitable to increase or maintain the femoral neck BMD in people with a high risk of osteoporotic fracture.

Results shows that the largest strains occur in load begetting exercises such as walking, running and hopping. Interestingly, our results indicate that some exercises with similar HCFs, such equally walking at 4 km/h (second peak) and HABD at lx% RM, can induce different strain distributions at the femoral neck. Whereas for hopping the HCF and strain ranking are high in both femoral neck areas, this is not the instance for the 2nd top of walking which induce higher tensile strains in both the inferior and superior part and college compression strains at the superior office of the femoral neck compared to their corresponding HCFs ranking (Figs ii–7). In contrast, exercises with muscle action solitary seem not to result in similar strains. Most resistance training exercises impose significantly lower HCFs and strains than walking at 4 km/h (Table ane). It should be noted that the strain distribution due to the hip contact forces, tensile in the superior and compressive in the inferior part, is besides modulated past the muscle recruitment strategy. Large muscles, such equally the gluteal muscles, get active during the gait bicycle to counteract the articulation moment and affect the local strain distribution at the femoral cervix past generating compressive strains in the superior and tensile strains in the inferior role. Overall, resulting strains are therefore reduced during walking and running. This might explains the difference between the first and the 2nd tiptop of walking since gluteal muscles are merely agile during the offset peak. Equally a result the compression and tensile strains for the second peak are always higher compared to the commencement meridian of walking. Therefore, our results propose that high HCFs are strongly related to the strain distribution in the proximal office of the femur and are influenced past bending and torsion as a consequence of the local muscle activeness equally well as HCFs. The latter may explain the lower tensile strains for the hip flexion/extension and hip abduction/adduction at 80% RM at the superior part of the femoral neck in our report compared to the values reported by Martelli et al.

The osteogenic potential of an exercise however depends not simply on the strain ranking merely as well fracture run a risk needs to exist taken into account when selecting training exercises. In linear FEA, the bone fraction that exceeds a specific threshold is often used equally a definition of failure. The Pistoia criterion states that if 2% of the tissue exceeds an effective strain of 7000 μstrains (43) information technology is likely that a fracture will occur. Using this criterion, hopping would be considered every bit an exercise with a high risk of fracture in elderly and may therefore not exist suitable every bit a training exercise.

Limitations

A workflow combining musculoskeletal modeling and FEA was used in this study to adequately represent the mechanical environment including all musculus and reaction forces interim on the femur during various concrete exercises. However, limitations are inherent to this approach. Calculation of muscle forces, and consequently joint forces, is subject to the model and optimization technique used. Static optimization has been found to satisfactorily reproduce muscle activation patterns during walking [43,44] and hopping [45], although the produced strength magnitudes still remain invalidated due to the impracticability of in vivo information acquisition.

Other factors such as the model's boundary conditions, material properties and geometry may affect our results in a certain corporeality. A CT-browse of the femur of a healthy 60 year one-time male person was selected as a template to estimate the material backdrop of an elderly female population, given that the HU template was close to the average HU distribution of 9 post-menopausal elderly subjects normalized by their HU range. Yet, differences in material properties e.one thousand. a lower BMD as nowadays in an osteoporotic population, would showroom college strains due to the lower elastic modulus compared to a healthy population and may therefore alter our results. Alternatively, BMD of cadaveric samples could accept been used [16,35,46]. All the same, given the frailty of these donors, fabric properties would not have been representative for the more than active elderly population which are likely to have an influence on the BMD and material properties due to a more frequent mechanical loading.

In the current study, a femur with an identical geometry of the generic musculoskeletal model uniformly scaled to represent the subject'southward anthropometry was used for all subjects in the FEA. Every bit a result, geometrical variations in the proximal femur that volition inherently affect the calculated strains for each subject, were non accounted for in the current study. However, this approach guarantees dynamic consistencies between the geometry of the musculoskeletal and FE model. Future research will therefore focus on the inclusion of the subject-specific geometry in both the musculoskeletal and FE models, as well equally field of study-specific material backdrop, loading and purlieus conditions to yield more physiological strain estimates in this specific cohort.

Applying a failure benchmark, hopping would be considered as an exercise with a loftier fracture risk. Notwithstanding, such criteria are depending on bone geometry, mesh, fabric properties and loading weather and should exist interpreted carefully given the inferior concrete condition in the elderly [47]. Nevertheless, nosotros experience that the conclusions based on relative comparisons of the strain magnitudes are still valid as long equally volume, frequency and duration of each exercise and the grooming program is adequate. This also indicates the need for more than clinical grooming studies on the effect of strains on the BMD at the proximal femur to determine the osteogenic potential of specific preparation exercises.

Decision

The present study provides a comparative analysis of strain data occurring at the superior and inferior part of the femoral neck during potentially osteogenic exercises performed by healthy mail-menopausal women. A comparison between the strain magnitudes and the peak HCFs for different exercises revealed that factors such as musculus recruitment strategy take an influence on the strain distribution specially at the superior office of the femoral neck. Since superior femoral neck frailness is related to elevated hip fracture take chances [32,48–52], exercises such as fast walking and running can be highly recommended to stimulate this item area to address femoral neck fragility. The use of hopping needs to be considered cautiously given the high strains and fracture chance reported. In decision, our results suggest that a training program including fast walking (above 5 km/h) and running exercises may increase or preserve the BMD at the femoral cervix. Future piece of work will address the inclusion of more subject-specific details in the musculoskeletal and FE models. Ultimately, a os density adaptation model can be implemented to evaluate the osteogenic response over time and the efficacy of a specific grooming programme in preventing bone loss at the femoral neck.

Supporting data

Acknowledgments

The authors would like to give thanks all the participants in this study for their outstanding cooperation.

References

1. i. Hernlund Eastward, Svedbom A, Ivergård One thousand, Compston J, Cooper C, Stenmark J, et al. Osteoporosis in the European Marriage: medical management, epidemiology and economic brunt. Arch Osteoporos. 2013 January;eight(1–2):136.
   • View Article
   • Google Scholar
2. ii. Boonen S, Dejaeger Due east, Vanderschueren D, Venken K, Bogaerts A, Verschueren S, et al. Osteoporosis and osteoporotic fracture occurrence and prevention in the elderly: a geriatric perspective. Best Pract Res Clin Endocrinol Metab. Elsevier Ltd; 2008;22(5):765–85. pmid:19028356
   • View Article
   • PubMed/NCBI
   • Google Scholar
3. 3. Frost HM. From Wolff's police force to the Utah image: Insights about bone physiology and its clinical applications. Vol. 262, Anatomical Tape. 2001. p. 398–419.
4. four. Frost HM. Bone's mechanostat: A 2003 update. Anat Rec. Wiley Online Library; 2003;275A(2):1081–101.
   • View Commodity
   • Google Scholar
5. 5. Bassett CAL, Becker RO. Generation of electrical potentials past bone in response to mechanical stress. Science (80-). American Association for the Advancement of Scientific discipline; 1962;137(3535):1063–four.
   • View Article
   • Google Scholar
6. 6. Kemmler W, Stengel S Von. Exercise and osteoporosis-related fractures: perspectives and recommendations of the sports and exercise scientist. Phys Sportsmed. 2011;39(1):142–57. pmid:21378497
   • View Article
   • PubMed/NCBI
   • Google Scholar
7. 7. Biewener A. Rubber Factors in Bone Strength. Calc Tiss Int. 1993;53:S68–74.
   • View Commodity
   • Google Scholar
8. eight. Chen JC, Jacobs CR. Mechanically induced osteogenic lineage delivery of stem cells. Stem Jail cell Res Ther. 2013 Sep;4(5):107. pmid:24004875
   • View Commodity
   • PubMed/NCBI
   • Google Scholar
9. 9. Carter DR. Mechanical loading histories and cortical bone remodeling. Calcif Tissue Int. Springer; 1984;36(1):S19–24.
   • View Article
   • Google Scholar
10. 10. Cowin SC. Mechanical modeling of the stress adaptation procedure in os. Calcif Tissue Int. Springer; 1984;36(1):S98–103.
    • View Article
    • Google Scholar
11. xi. Huiskes R., Weinans H., Grootenboer H. J., Dalstra M., Fudala B. & TJS . Adaptive Bone-Remodeling Theory Practical Analysis. J Biomech. 1987;20:1135–l. pmid:3429459
    • View Article
    • PubMed/NCBI
    • Google Scholar
12. 12. Martyn-St James M, Carroll Southward. A meta-analysis of impact practise on postmenopausal bone loss: the example for mixed loading do programmes. Br J Sports Med. 2009 Dec;43(12):898–908. pmid:18981037
    • View Article
    • PubMed/NCBI
    • Google Scholar
13. 13. Martyn-St James M, Carroll Due south. Meta-analysis of walking for preservation of bone mineral density in postmenopausal women. Bone. 2008 Sep;43(3):521–31. pmid:18602880
    • View Article
    • PubMed/NCBI
    • Google Scholar
14. 14. Kim WS, Kim EY. Comparing self-selected speed walking of the elderly with self-selected slow, moderate, and fast speed walking of young adults. Ann Rehabil Med. 2014;38(1):101–8. pmid:24639933
    • View Article
    • PubMed/NCBI
    • Google Scholar
15. 15. Nikander R, Sievänen H, Heinonen A, Daly RM, Uusi-Rasi K, Kannus P. Targeted do against osteoporosis: A systematic review and meta-assay for optimising bone strength throughout life. BMC Med. 2010;8:47. pmid:20663158
    • View Article
    • PubMed/NCBI
    • Google Scholar
16. sixteen. Martelli S, Kersh ME, Schache AG, Pandy MG. Strain energy in the femoral neck during exercise. J Biomech. Elsevier; 2014;47(8):1784–91. pmid:24746018
    • View Article
    • PubMed/NCBI
    • Google Scholar
17. 17. Martyn-St James Thousand, Carroll S. High-intensity resistance training and postmenopausal bone loss: a meta-assay. Osteoporos Int. 2006 Jan;17(8):1225–40. pmid:16823548
    • View Article
    • PubMed/NCBI
    • Google Scholar
18. xviii. Gomez-Cabello A, Ara I, Gonzalez-Aguero A, Casajus JA, Vicente-Rodriguez M. Furnishings of training on bone mass in older adults: a systematic review. Sports Med. 2012;42(4):301–25. pmid:22376192
    • View Article
    • PubMed/NCBI
    • Google Scholar
19. 19. Giarmatzis Grand, Jonkers I, Baggen R, Verschueren Due south. Less hip articulation loading only during running rather than walking in elderly compared to young adults. Gait Posture. Elsevier B.V.; 2017;53:155–61. pmid:28161687
    • View Article
    • PubMed/NCBI
    • Google Scholar
20. twenty. Brownish LE, Weir JP. ASEP Procedures Recommendation I: Accurate Assessment Of Muscular Forcefulness And Power. An Int Electron J. 2001;four(3):1–21.
    • View Article
    • Google Scholar
21. 21. Giarmatzis G, Jonkers I, Wesseling Chiliad, Van Rossom S, Verschueren S. Loading of hip measured by hip contact forces at unlike speeds of walking and running. J Bone Miner Res. 2015;31(four):1431–40.
    • View Commodity
    • Google Scholar
22. 22. Hamner SR, Seth A, Delp SL. Muscle contributions to propulsion and support during running. J Biomech. 2010 Oct;43(xiv):2709–sixteen. pmid:20691972
    • View Article
    • PubMed/NCBI
    • Google Scholar
23. 23. De Groote F, De Laet T, Jonkers I, De Schutter J. Kalman smoothing improves the estimation of joint kinematics and kinetics in marker-based human gait analysis. J Biomech. 2008 Dec;41(16):3390–8. pmid:19026414
    • View Article
    • PubMed/NCBI
    • Google Scholar
24. 24. Steele KM, DeMers MS, Schwartz MH, Delp SL. Compressive tibiofemoral force during hunker gait. Gait Posture. Elsevier B.V.; 2012;35(4):556–60. pmid:22206783
    • View Article
    • PubMed/NCBI
    • Google Scholar
25. 25. van Arkel RJ, Modenese L, Phillips ATM, Jeffers JRT. Hip abduction can preclude posterior border loading of hip replacements. J Orthop Res. 2013 Aug;31(viii):1172–9. pmid:23575923
    • View Article
    • PubMed/NCBI
    • Google Scholar
26. 26. Bitsakos C, Kerner J, Fisher I, Amis AA. The consequence of muscle loading on the simulation of os remodelling in the proximal femur. J Biomech. 2005;38(one):133–ix. pmid:15519348
    • View Article
    • PubMed/NCBI
    • Google Scholar
27. 27. Vahdati a., Walscharts Southward, Jonkers I, Garcia-aznar JMM, Sloten J Vander, Lenthe GH Van, et al. Function of Subject-Specific Musculoskeletal Loading on The Prediction of Os Density Distribution in the Proximal Femur. J Mech Behav Biomed Mater. Elsevier; 2013 December;thirty:244–52. pmid:24342624
    • View Commodity
    • PubMed/NCBI
    • Google Scholar
28. 28. Morgan EF, Bayraktar HH, Keaveny TM. Trabecular bone modulus–density relationships depend on anatomic site. J Biomech. 2003 Jul;36(7):897–904. pmid:12757797
    • View Commodity
    • PubMed/NCBI
    • Google Scholar
29. 29. Garcia JM, Martínez M a, Doblaré M. An anisotropic internal-external bone adaptation model based on a combination of CAO and continuum damage mechanics technologies. Comput Methods Biomech Biomed Engin. 2001 Jan;4(4):355–77. pmid:11328645
    • View Article
    • PubMed/NCBI
    • Google Scholar
30. xxx. Speirs AD, Heller MO, Duda GN, Taylor WR. Physiologically based boundary weather in finite chemical element modelling. J Biomech. 2007;forty(x):2318–23. pmid:17166504
    • View Article
    • PubMed/NCBI
    • Google Scholar
31. 31. Milovanovic P, Djonic D, Marshall RP, Hahn Thousand, Nikolic South, Zivkovic V, et al. Micro-structural basis for detail vulnerability of the superolateral cervix trabecular bone in the postmenopausal women with hip fractures. Bone. Elsevier Inc.; 2012;50(1):63–8. pmid:21964412
    • View Article
    • PubMed/NCBI
    • Google Scholar
32. 32. Johannesdottir F, Poole KES, Reeve J, Siggeirsdottir K, Aspelund T, Mogensen B, et al. Distribution of cortical bone in the femoral neck and hip fracture: A prospective instance-command analysis of 143 incident hip fractures; the AGES-REYKJAVIK Study. Bone. Elsevier Inc.; 2011;48(6):1268–76. pmid:21473947
    • View Article
    • PubMed/NCBI
    • Google Scholar
33. 33. Baker R. ISB recommendation on definition of joint coordinate systems for the reporting of man articulation motion—part I: ankle, hip and spine. J Biomech. Elsevier; 2003;36(2):300–2. pmid:12547371
    • View Article
    • PubMed/NCBI
    • Google Scholar
34. 34. Taylor ME, Tanner KE, Freeman MAR, Yettram AL. Stress and strain distribution within the intact femur: Compression or bending? Med Eng Phys. 1996;18(two):122–31. pmid:8673318
    • View Article
    • PubMed/NCBI
    • Google Scholar
35. 35. Anderson DE, Madigan ML. Furnishings of age-related differences in femoral loading and bone mineral density on strains in the proximal femur during controlled walking. J Appl Biomech. NIH Public Access; 2013;29(5):505. pmid:23185080
    • View Article
    • PubMed/NCBI
    • Google Scholar
36. 36. Howe TE, Shea B, Dawson LJ, Downie F, Murray A, Ross C, et al. Practise for preventing and treating osteoporosis in postmenopausal women. Cochrane Database Syst Rev. Chichester, UK: John Wiley & Sons, Ltd; 2011 Jul 6;(7):CD000333. pmid:21735380
    • View Article
    • PubMed/NCBI
    • Google Scholar
37. 37. Ma D, Wu 50, He Z. Effects of walking on the preservation of os mineral density in perimenopausal and postmenopausal women: a systematic review and meta-assay. Menopause. 2013;20(xi):1216–26. pmid:24149921
    • View Commodity
    • PubMed/NCBI
    • Google Scholar
38. 38. Bailey C a, Brooke-Wavell G. Optimum frequency of exercise for bone wellness: randomised controlled trial of a high-impact unilateral intervention. Bone. Elsevier Inc.; 2010 April;46(4):1043–9. pmid:20004758
    • View Article
    • PubMed/NCBI
    • Google Scholar
39. 39. Allison SJ, Folland JP, Rennie WJ, Summers GD, Brooke-Wavell K. High impact exercise increased femoral neck bone mineral density in older men: A randomised unilateral intervention. Bone. Elsevier Inc.; 2013 April;53(ii):321–8. pmid:23291565
    • View Article
    • PubMed/NCBI
    • Google Scholar
40. 40. Allison SJ, Poole KES, Treece GM, Gee AH, Tonkin C, Rennie WJ, et al. The influence of high-impact exercise on cortical and trabecular bone mineral content and 3D distribution across the proximal femur in older men: A randomized controlled unilateral intervention. J Os Miner Res. 2015;xxx(9):1709–16. pmid:25753495
    • View Article
    • PubMed/NCBI
    • Google Scholar
41. 41. Kelley G a, Kelley KS, Tran Z V. Resistance training and os mineral density in women: a meta-analysis of controlled trials. Am J Phys Med Rehabil. 2001 Jan;lxxx(1):65–77. pmid:11138958
    • View Commodity
    • PubMed/NCBI
    • Google Scholar
42. 42. Kerr D, Ackland T, Maslen B, Morton a, Prince R. Resistance training over 2 years increases os mass in calcium-replete postmenopausal women. J Os Miner Res. 2001 January;xvi(ane):175–81. pmid:11149482
    • View Article
    • PubMed/NCBI
    • Google Scholar
43. 43. Anderson FC, Pandy MG. Static and dynamic optimization solutions for gait are practically equivalent. J Biomech. 2001 Feb;34(2):153–61. pmid:11165278
    • View Article
    • PubMed/NCBI
    • Google Scholar
44. 44. Modenese L, Phillips ATM. Prediction of hip contact forces and muscle activations during walking at different speeds. Multibody Syst Dyn. 2011 Nov;28(1–two):157–68.
    • View Article
    • Google Scholar
45. 45. Mokhtarzadeh H, Perraton L, Fok L, Muñoz M a, Clark R, Pivonka P, et al. A comparison of optimisation methods and knee joint joint degrees of liberty on muscle forcefulness predictions during single-leg hop landings. J Biomech. Elsevier; 2014 Aug;one–6.
    • View Article
    • Google Scholar
46. 46. Edwards WB, Miller RH, Derrick TR. Femoral strain during walking predicted with muscle forces from static and dynamic optimization. J Biomech. Elsevier; 2016;49(7):1206–13. pmid:26994784
    • View Article
    • PubMed/NCBI
    • Google Scholar
47. 47. Engelke K, van Rietbergen B, Zysset P. FEA to Measure Bone Strength: A Review. Vol. 14, Clinical Reviews in Bone and Mineral Metabolism. Springer The states; 2016. p. 26–37.
48. 48. Bell KL, Loveridge Northward, Power J, Garrahan N, Stanton G, Lunt M, et al. Construction of the femoral neck in hip fracture: Cortical os loss in the inferoanterior to superoposterior axis. J Os Miner Res. 1999;xiv(1):111–9. pmid:9893072
    • View Article
    • PubMed/NCBI
    • Google Scholar
49. 49. Thomas CDL, Mayhew PM, Ability J, Poole KES, Loveridge N, Clement JG, et al. Femoral Neck Trabecular Bone: Loss With Crumbling and Role in Preventing Fracture. 2009;24(11):1808–18. pmid:19419312
    • View Commodity
    • PubMed/NCBI
    • Google Scholar
50. 50. Poole KES, Mayhew PM, Rose CM, Brown JK, Bearcroft PJ, Loveridge Northward, et al. Changing structure of the femoral cervix across the adult female lifespan. J Bone Miner Res. 2010;25(iii):482–91. pmid:19594320
    • View Commodity
    • PubMed/NCBI
    • Google Scholar
51. 51. Loveridge Due north, Power J, Reeve J, Boyde A. Os mineralization density and femoral neck fragility. Bone. 2004;35(four):929–41. pmid:15454100
    • View Article
    • PubMed/NCBI
    • Google Scholar
52. 52. Mayhew PM, Thomas CD, Clement JG, Loveridge N, Brook TJ, Bonfield West, et al. Relation betwixt historic period, femoral neck cortical stability, and hip fracture adventure. Lancet. 2005;366(9480):129–35. pmid:16005335
    • View Article
    • PubMed/NCBI
    • Google Scholar

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