Identifying factors related to Achilles tendon stress, strain, and stiffness before and after 6 months of growth in youth 10–14 years of age (original) (raw)
Related papers
Age-related changes in mechanical properties of the Achilles tendon
Journal of Anatomy, 2012
The stiffness of a tendon, which influences muscular force transfer to the skeleton and increases during childhood, is dependent on its material properties and dimensions, both of which are influenced by chronic loading. The aims of this study were to: (i) determine the independent contributions of body mass, force production capabilities and tendon dimensions to tendon stiffness during childhood; and (ii) descriptively document age-related changes in tendon mechanical properties and dimensions. Achilles tendon mechanical and material properties were determined in 52 children (5-12 years) and 19 adults. Tendon stiffness and Young's modulus (YM) were calculated as the slopes of the force-elongation and stress-strain curves, respectively. Relationships between stiffness vs. age, mass and force, and between YM vs. age, mass and stress were determined by means of polynomial fits and multiple regression analyses. Mass was found to be the best predictor of stiffness, whilst stress was best related to YM (< 75 and 51% explained variance, respectively). Combined, mass and force accounted for up to 78% of stiffness variation. Up to 61% of YM variability could be explained using a combination of mass, stress and age. These results demonstrate that age-related increases in tendon stiffness are largely attributable to increased tendon loading from weight-bearing tasks and increased plantarflexor force production, as well as tendon growth. Moreover, our results suggest that chronic increases in tendon loading during childhood result in microstructural changes which increase the tendon's YM. Regarding the second aim, peak stress increased from childhood to adulthood due to greater increases in strength than tendon cross-sectional area. Peak strain remained constant as a result of parallel increases in tendon length and peak elongation. The differences in Achilles tendon properties found between adults and children are likely to influence force production, and ultimately movement characteristics, which should be explicitly examined in future research.
Training-induced Achilles tendon adaptation: a distinct population within adolescence
Journal of Physical Education and Sport, 2023
The Achilles tendon functions as a load-bearing component crucial for movement performance and swiftly adapts to changes in body mass and strength, particularly during periods of growth spurts. Mechanical and morphological attributes of the Achilles tendon were assessed in 41 participants (20 boys and 21 girls, comprising 22 athletes and 19 nonathletes) over a span of 18 months, employing ramped isometric plantar flexion. Longitudinal variations were analyzed using linear mixed modeling. This longitudinal study aimed to explore the combined effects of sport participation, maturation, and sex on the mechanical characteristics of the Achilles tendon across various muscle-tendon lengths. While the rate of stiffness increase post peak height velocity was comparable across all groups, a noteworthy finding was that boy-athletes displayed a more pronounced and earlier rate of Achilles tendon stiffness augmentation twelve months prior to PHV. Additionally, a distinctive mechanical property alteration was identified solely in boy-athletes at the 0° ankle angle. This elevation in Achilles tendon stiffness among boy-athletes was linked to greater peak force of the plantar flexors and a reduction in elongation. In summary, our study introduces novel longitudinal evidence indicating that sport participation interacts with sex and maturation, yielding a distinct adaptive response in Achilles tendon stiffness, specifically observed at the neutral position. These findings suggest a nuanced adaptive model wherein elevated force levels preceding PHV instigate heightened mechanical loading in specific muscle-tendon lengths, thereby inducing increased stiffness throughout adolescence. Specifically, the Achilles tendon stiffness exhibited a more substantial rate of increase in athletes compared to nonathletes and girls, leading to the conclusion that boyathletes represent a distinct population during the maturation process.
Scandinavian Journal of Medicine & Science in Sports, 2007
We examined whether long-term habitual training (a) was associated with differences in structural and mechanical properties in tendon in women and (b) yielded different tendon properties in men and women. Ten male runners, 10 female runners and 10 female non-runners were tested. Tendon cross-sectional area (CSA) and length of the patellar and Achilles tendon were determined with MRI. Ultrasonography-based measurement of tendon elongation and force during isometric contractions provided mechanical properties. Distal patellar and Achilles tendon CSAs were greater than the proximal part in all three groups (Po0.05). Weight-normalized Achilles tendon CSA were similar in trained (2.78 AE 0.17 mm 2 /kg 3/4) and untrained women (2.60 AE 0.13 mm 2 /kg 3/4), while that in trained men (3.77 AE 0.27 mm 2 /kg 3/4) was greater compared with trained women (Po0.01). Patellar tendon CSA were comparable in trained and untrained women, while that in trained men was greater compared with trained women (Po0.01). Patellar tendon stiffness was greater in male runners (3528 AE 773 N/mm) compared with female runners (2069 AE 666 N/mm) and non-runners (2477 AE 381 N/mm), (Po0.01), but patellar tendon deformation, stress, strain and modulus were similar. These data indirectly suggest that the ability of Achilles and patellar tendons to adapt in response to habitual loading such as running is attenuated in women.
The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, 2003
The Achilles tendon cross-sectional area (CSA), tensile force, and stress during an isometric contraction were examined in healthy young (n = 9, age = 29 +/- 1 years, mean +/- SEM) and elderly (n = 10, 79 +/- 2 years) women. CSA area was obtained with magnetic resonance imaging 3 cm proximal to the insertion, and tendon force was obtained from the isometric ankle moment. The moment of force about the ankle joint was greater in young women (95 +/- 17 N m) than in elderly women (51 +/- 5 N m; p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.05). The Achilles tendon CSA was significantly greater in elderly women (56.3 +/- 3.0 mm(2)) than in young women (46.0 +/- 1.9 mm(2); p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.01). These data show that young women can exert a greater force than elderly women on the Achilles tendon during voluntary contraction, although elderly women have an increased (22%) tendon CSA, and a lower tendon force than young women. The greater tendon size combines to lower the stress on the tendon markedly, which may reduce the risk of injury to the tendon.
Scand J Med Sci Sports, 2007
We examined whether long-term habitual training (a) was associated with differences in structural and mechanical properties in tendon in women and (b) yielded different tendon properties in men and women. Ten male runners, 10 female runners and 10 female non-runners were tested. Tendon cross-sectional area (CSA) and length of the patellar and Achilles tendon were determined with MRI. Ultrasonography-based measurement of tendon elongation and force during isometric contractions provided mechanical properties. Distal patellar and Achilles tendon CSAs were greater than the proximal part in all three groups (Po0.05). Weight-normalized Achilles tendon CSA were similar in trained (2.78 AE 0.17 mm 2 /kg 3/4) and untrained women (2.60 AE 0.13 mm 2 /kg 3/4), while that in trained men (3.77 AE 0.27 mm 2 /kg 3/4) was greater compared with trained women (Po0.01). Patellar tendon CSA were comparable in trained and untrained women, while that in trained men was greater compared with trained women (Po0.01). Patellar tendon stiffness was greater in male runners (3528 AE 773 N/mm) compared with female runners (2069 AE 666 N/mm) and non-runners (2477 AE 381 N/mm), (Po0.01), but patellar tendon deformation, stress, strain and modulus were similar. These data indirectly suggest that the ability of Achilles and patellar tendons to adapt in response to habitual loading such as running is attenuated in women.
Medical Science
Aim of the study: our study aims to report if there is a gender difference in length of the Achilles tendon by measuring achilles tendon rest angle in relation to body parameters of the physical therapy students as adult samples. Methods: Measuring the resting angle of the Achilles tendon by goniometer for 134 students (106) male students and (28) female students and correlate with age, gender, body height, weight. Results: the mean Achilles tendon resting angle in male students 21.54º, SEM 3.27º and female students 22.42º SEM 2.83º with a total of 21.73º SEM 3.20º respectively, the tendon length correlates with the male student's height mean (172.18±8.29) and female students height (164.89±7.65) with total (170.66±8.66) respectively with higher correlation in the female students (0.637) than male students (0.383). On other hand, there is no correlation to age, weight with male students (72.15±11.18) and female students (72.57±14.13) with a total (72.23±11.80) respectively. Conclusions: there is a gender difference in achilles tendon length in relation to height with more correlation in females than males in the age of the adulthood.
Frontiers in Physiology
Knowledge regarding the effects of athletic training on the properties of muscle and tendon in preadolescent children is scarce. The current study compared Achilles tendon stiffness, plantar flexor muscle strength and vertical jumping performance of preadolescent athletes and non-athletes to provide insight into the potential effects of systematic athletic training. Twenty-one preadolescent artistic gymnastic athletes (9.2 ± 1.6 years, 15 girls) and 11 similar-aged non-athlete controls (9.0 ± 1.7 years, 6 girls) participated in the study. The training intensity and volume of the athletes was documented for the last 6 months before the measurements. Subsequently, vertical ground reaction forces were measured with a force plate to assess jumping performance during squat (SJ) and countermovement jumps (CMJ) in both groups. Muscle strength of the plantar flexor muscles and Achilles tendon stiffness were examined using ultrasound, electromyography, and dynamometry. The athletes trained 6 days per week with a total of 20 h of training per week. Athletes generated significantly greater plantar flexion moments normalized to body mass compared to non-athletes (1.75 ± 0.32 Nm/kg vs. 1.31 ± 0.33 Nm/kg; p = 0.001) and achieved a significantly greater jump height in both types of jumps (21.2 ± 3.62 cm vs. 14.9 ± 2.32 cm; p < 0.001 in SJ and 23.4 ± 4.1 cm vs. 16.4 ± 4.1 cm; p < 0.001 in CMJ). Achilles tendon stiffness did not show any statistically significant differences (p = 0.413) between athletes (116.3 ± 32.5 N/mm) and non-athletes (106.4 ± 32.8 N/mm). Athletes were more likely to reach strain magnitudes close to or higher than 8.5% strain compared to non-athletes (frequency: 24% vs. 9%) indicating an increased mechanical demand for the tendon.
Acta Orthopaedica et Traumatologica Turcica, 2017
Objective: The purpose of this study is to assess the effect and correlation of gender, body mass index (BMI) and quadriceps femoris (QF) muscle strength on patellar tendon (PT) thickness and stiffness in healthy sedentary individuals. Methods: This study was carried out with 67 (36 female, 31 male) healthy sedentary individuals between the ages of 18e44 (28.0 ± 7.5 years). The individuals included in the study were divided into two groups according to their gender and BMI (18.5 < BMI < 25 and 25 < BMI). The body composition was determined with Tanita Body Composition Analyser. PT thickness and stiffness was measured with ACUSON S3000 Ultrasonography Device using 9L4 ultrasonography probe. QF concentric muscle strength of the individuals was measured with Biodex ® System 4 Dynamometer at 60 /sec angular speed. Results: It was found that PT stiffness was higher in males compared to females (p < 0.001). It was found that PT stiffness was lower in obese individuals compared to individuals with normal weight (p ¼ 0.017). A negative and weak correlation was found between BMI and PT stiffness (r ¼ À0.26, p ¼ 0.032), whereas a negative and moderate correlation was found between fat percentage and PT stiffness (r ¼ À0.50, p < 0.001). A moderate correlation was found between BMI and PT thickness (r ¼ 0.54, p < 0.001). It was found that peak torque at 60 /sec angular speed had a moderate correlation with PT stiffness (r ¼ 0.44, p < 0.001) and PT thickness (r ¼ 0.45, p < 0.001). Conclusions: PT stiffness is correlated and affected by gender, BMI and QF muscle strength whereas PT thickness is correlated and affected only to BMI and QF muscle strength.