Lu, T. W. & Chang, C. F. Biomechanics of human movement and its clinical applications. Kaohsiung J. Med. Sci. 28, S13-25. https://doi.org/10.1016/j.kjms.2011.08.004 (2012).
Google Scholar
LeBlanc, A. D., Spector, E. R., Evans, H. J. & Sibonga, J. D. Skeletal responses to space flight and the bed rest analog: A review. J. Musculoskelet. Neuronal Interact. 7, 33–47 (2007).
Google Scholar
Moosavi, D. et al. The effects of spaceflight microgravity on the musculoskeletal system of humans and animals, with an emphasis on exercise as a countermeasure: A systematic scoping review. Physiol. Res. 70, 119–151. https://doi.org/10.33549/physiolres.934550 (2021).
Google Scholar
Juhl, O. J. et al. Update on the effects of microgravity on the musculoskeletal system. NPJ Microgr. 7, 28. https://doi.org/10.1038/s41526-021-00158-4 (2021).
Google Scholar
Hackney, K. J. et al. The astronaut-athlete: Optimizing human performance in space. J. Strength Cond. Res. 29, 3531–3545. https://doi.org/10.1519/JSC.0000000000001191 (2015).
Google Scholar
Loehr, J. A. et al. Physical training for long-duration spaceflight. Aerosp. Med. Hum. Perform. 86, A14–A23. https://doi.org/10.3357/AMHP.EC03.2015 (2015).
Google Scholar
Scott, J. P. R., Weber, T. & Green, D. A. Editorial: Optimization of exercise countermeasures for human space flight-lessons from terrestrial physiology and operational implementation. Front. Physiol. 10, 1567. https://doi.org/10.3389/fphys.2019.01567 (2019).
Google Scholar
Ford, J. J. et al. Effects of specific muscle activation for low back pain on activity limitation, pain, work participation, or recurrence: A systematic review. Musculoskelet. Sci. Pract. 50, 102276 (2020).
Google Scholar
Stokes, M. et al. Recommendations for Future Post-mission Neuro-Musculoskeletal Reconditioning Research and Practice Post-mission Exercise (Reconditioning) Topical Team Report. (2016).
Worth Jr, M. H., Manning, F. J. & Longnecker, D. E. Review of NASA’s longitudinal study of astronaut health. (2004).
Lee, I. M. et al. Effect of physical inactivity on major non-communicable diseases worldwide: An analysis of burden of disease and life expectancy. Lancet 380, 219–229. https://doi.org/10.1016/S0140-6736(12)61031-9 (2012).
Google Scholar
Thomas, E. et al. Physical activity programs for balance and fall prevention in elderly: A systematic review. Medicine (Baltimore) 98, e16218. https://doi.org/10.1097/MD.0000000000016218 (2019).
Google Scholar
Graham, Z. A. et al. Mechanisms of exercise as a preventative measure to muscle wasting. Am. J. Physiol. Cell Physiol. 321, C40–C57. https://doi.org/10.1152/ajpcell.00056.2021 (2021).
Google Scholar
Garrett-Bakelman, F. E. et al. The NASA twins study: A multidimensional analysis of a year-long human spaceflight. Science 364, 6436. https://doi.org/10.1126/science.aau8650 (2019).
Google Scholar
Trappe, S. Effects of spaceflight, simulated spaceflight and countermeasures on single muscle fiber physiology. J. Gravit. Physiol. 9, P323-326 (2002).
Google Scholar
Colleran, P. N. et al. Alterations in skeletal perfusion with simulated microgravity: A possible mechanism for bone remodeling. J. Appl. Physiol. 1985(89), 1046–1054. https://doi.org/10.1152/jappl.2000.89.3.1046 (2000).
Google Scholar
Baskin, K. K., Winders, B. R. & Olson, E. N. Muscle as a “mediator” of systemic metabolism. Cell Metab. 21, 237–248. https://doi.org/10.1016/j.cmet.2014.12.021 (2015).
Google Scholar
Edgerton, V. R. et al. Sensorimotor adaptations to microgravity in humans. J. Exp. Biol. 204, 3217–3224. https://doi.org/10.1242/jeb.204.18.3217 (2001).
Google Scholar
Drummer, C. et al. Regulation and distribution of body fluid during a 6-day head-down tilt study in a randomized cross-over design. J. Gravit. Physiol. 7, P187-188 (2000).
Google Scholar
Schleip, R. et al. Passive muscle stiffness may be influenced by active contractility of intramuscular connective tissue. Med. Hypotheses 66, 66–71. https://doi.org/10.1016/j.mehy.2005.08.025 (2006).
Google Scholar
Briguglio, M. Nutritional orthopedics and space nutrition as two sides of the same coin: A scoping review. Nutrients 13, 483. https://doi.org/10.3390/nu13020483 (2021).
Google Scholar
Lambertz, D., Pérot, C., Kaspranski, R. & Goubel, F. Effects of long-term spaceflight on mechanical properties of muscles in humans. J. Appl. Physiol. 1985(90), 179–188. https://doi.org/10.1152/jappl.2001.90.1.179 (2001).
Google Scholar
Bartsch, K. et al. Assessing reliability and validity of different stiffness measurement tools on a multi-layered phantom tissue model. Sci. Rep. 13, 815. https://doi.org/10.1038/s41598-023-27742-w (2023).
Google Scholar
Mijailovic, A. S., Qing, B., Fortunato, D. & Van Vliet, K. J. Characterizing viscoelastic mechanical properties of highly compliant polymers and biological tissues using impact indentation. Acta Biomater. 71, 388–397. https://doi.org/10.1016/j.actbio.2018.02.017 (2018).
Google Scholar
Masi, A. T. & Hannon, J. C. Human resting muscle tone (HRMT): Narrative introduction and modern concepts. J. Bodyw. Mov. Ther. 12, 320–332. https://doi.org/10.1016/j.jbmt.2008.05.007 (2008).
Google Scholar
Simons, G. D. & Mense, S. Understanding and measurement of muscle tone as related to clinical muscle pain. Pain 75, 1–17. https://doi.org/10.1016/S0304-3959(97)00102-4 (1998).
Google Scholar
Agyapong-Badu, S., Warner, M., Samuel, D. & Stokes, M. Practical considerations for standardized recording of muscle mechanical properties using a myometric device: Recording site, muscle length, state of contraction and prior activity. J. Musculoskelet. Res. 21, 1850010 (2018).
Google Scholar
Bernabei, M., Lee, S. S., Perreault, E. J. & Sandercock, T. G. Shear wave velocity is sensitive to changes in muscle stiffness that occur independently from changes in force. J. Appl. Physiol. 128, 8–16 (2020).
Google Scholar
Agyapong-Badu, S., Warner, M., Samuel, D. & Stokes, M. Measurement of ageing effects on muscle tone and mechanical properties of rectus femoris and biceps brachii in healthy males and females using a novel hand-held myometric device. Arch. Gerontol. Geriatr. 62, 59–67. https://doi.org/10.1016/j.archger.2015.09.011 (2016).
Google Scholar
Dankel, S. J. & Razzano, B. M. The impact of acute and chronic resistance exercise on muscle stiffness: A systematic review and meta-analysis. J. Ultrasound 23, 473–480 (2020).
Google Scholar
Yu, H. K. et al. Performance of passive muscle stiffness in diagnosis and assessment of disease progression in duchenne muscular dystrophy. Ultrasound Med. Biol. 48, 414–421. https://doi.org/10.1016/j.ultrasmedbio.2021.09.003 (2022).
Google Scholar
Rätsep, T. & Asser, T. Changes in viscoelastic properties of skeletal muscles induced by subthalamic stimulation in patients with Parkinson’s disease. Clin. Biomech. (Bristol, Avon) 26, 213–217. https://doi.org/10.1016/j.clinbiomech.2010.09.014 (2011).
Google Scholar
Svantesson, U., Takahashi, H., Carlsson, U., Danielsson, A. & Sunnerhagen, K. S. Muscle and tendon stiffness in patients with upper motor neuron lesion following a stroke. Eur. J. Appl. Physiol. 82, 275–279. https://doi.org/10.1007/s004210000216 (2000).
Google Scholar
Demangel, R. et al. Early structural and functional signature of 3-day human skeletal muscle disuse using the dry immersion model. J. Physiol. 595, 4301–4315. https://doi.org/10.1113/JP273895 (2017).
Google Scholar
Schneider, S., Peipsi, A., Stokes, M., Knicker, A. & Abeln, V. Feasibility of monitoring muscle health in microgravity environments using Myoton technology. Med. Biol. Eng. Comput. 53, 57–66. https://doi.org/10.1007/s11517-014-1211-5 (2015).
Google Scholar
Technology – Myoton. (2023).
Lee, Y., Kim, M. & Lee, H. The measurement of stiffness for major muscles with shear wave elastography and myoton: A quantitative analysis study. Diagnostics 11, 524 (2021).
Google Scholar
Chuang, L. L., Wu, C. Y., Lin, K. C. & Lur, S. Y. Quantitative mechanical properties of the relaxed biceps and triceps brachii muscles in patients with subacute stroke: A reliability study of the myoton-3 myometer. Stroke Res. Treat. 2012, 617694. https://doi.org/10.1155/2012/617694 (2012).
Google Scholar
García-Bernal, M. I., González-García, P., Madeleine, P., Casuso-Holgado, M. J. & Heredia-Rizo, A. M. Characterization of the structural and mechanical changes of the biceps brachii and gastrocnemius muscles in the subacute and chronic stage after stroke. Int. J. Environ. Res. Public Health 20, 1405. https://doi.org/10.3390/ijerph20021405 (2023).
Google Scholar
Muckelt, P. E. et al. Protocol and reference values for minimal detectable change of MyotonPRO and ultrasound imaging measurements of muscle and subcutaneous tissue. Sci. Rep. 12, 13654. https://doi.org/10.1038/s41598-022-17507-2 (2022).
Google Scholar
Jarocka, E., Marusiak, J., Kumorek, M., Jaskólska, A. & Jaskólski, A. Muscle stiffness at different force levels measured with two myotonometric devices. Physiol. Meas. 33, 65 (2011).
Google Scholar
Hu, X. et al. Quantifying paraspinal muscle tone and stiffness in young adults with chronic low back pain: A reliability study. Sci. Rep. 8, 14343. https://doi.org/10.1038/s41598-018-32418-x (2018).
Google Scholar
Bierman, W. The temperature of the skin surface. JAMA 106, 1158–1162. https://doi.org/10.1001/jama.1936.02770140020007 (1936).
Google Scholar
Yoon, S.-W., Lee, J.-W., Kim, M.-J., Kim, S.-H. & Park, W.-S. A study of muscular activities and onset times of the tibialis anterior and medial gastrocnemius muscles of elderly people in climbing stairs. J. Phys. Ther. Sci. 24, 767–770 (2012).
Google Scholar
Petersen, N. et al. Exercise in space: The European Space Agency approach to in-flight exercise countermeasures for long-duration missions on ISS. Extrem Physiol. Med. 5, 9. https://doi.org/10.1186/s13728-016-0050-4 (2016).
Google Scholar
Fitts, R. H. et al. Prolonged space flight-induced alterations in the structure and function of human skeletal muscle fibres. J. Physiol. 588, 3567–3592. https://doi.org/10.1113/jphysiol.2010.188508 (2010).
Google Scholar
Koryak, Y. A. Changes in human skeletal muscle architecture and function induced by extended spaceflight. J. Biomech. 97, 109408. https://doi.org/10.1016/j.jbiomech.2019.109408 (2019).
Google Scholar
Rubenson, J., Pires, N. J., Loi, H. O., Pinniger, G. J. & Shannon, D. G. On the ascent: The soleus operating length is conserved to the ascending limb of the force-length curve across gait mechanics in humans. J. Exp. Biol. 215, 3539–3551. https://doi.org/10.1242/jeb.070466 (2012).
Google Scholar
Kubo, K. et al. Effects of 20 days of bed rest on the viscoelastic properties of tendon structures in lower limb muscles. Br. J. Sports Med. 38, 324–330. https://doi.org/10.1136/bjsm.2003.005595 (2004).
Google Scholar
Schoenrock, B. et al. Bed rest, exercise countermeasure and reconditioning effects on the human resting muscle tone system. Front. Physiol. 9, 810. https://doi.org/10.3389/fphys.2018.00810 (2018).
Google Scholar
Labonte, D. & Holt, N. C. Elastic energy storage and the efficiency of movement. Curr. Biol. 32, R661–R666 (2022).
Google Scholar
Obst, S. J., Newsham-West, R. & Barrett, R. S. Changes in Achilles tendon mechanical properties following eccentric heel drop exercise are specific to the free tendon. Scand. J. Med. Sci. Sports 26, 421–431. https://doi.org/10.1111/sms.12466 (2016).
Google Scholar
Chang, T. T. et al. Objective assessment of regional stiffness in achilles tendon in different ankle joint positions using the MyotonPRO. Med. Sci. Monit. 26, e926407. https://doi.org/10.12659/MSM.926407 (2020).
Google Scholar
Magnusson, S. P., Narici, M. V., Maganaris, C. N. & Kjaer, M. Human tendon behaviour and adaptation, in vivo. J. Physiol. 586, 71–81. https://doi.org/10.1113/jphysiol.2007.139105 (2008).
Google Scholar
Lorimer, A. V. & Hume, P. A. Stiffness as a risk factor for achilles tendon injury in running athletes. Sports Med. 46, 1921–1938. https://doi.org/10.1007/s40279-016-0526-9 (2016).
Google Scholar
Holm, C., Kjaer, M. & Eliasson, P. Achilles tendon rupture–treatment and complications: A systematic review. Scand. J. Med. Sci. Sports 25, e1-10. https://doi.org/10.1111/sms.12209 (2015).
Google Scholar
Morgan, G. E., Martin, R., Williams, L., Pearce, O. & Morris, K. Objective assessment of stiffness in Achilles tendinopathy: A novel approach using the MyotonPRO. BMJ Open Sport Exerc. Med. 4, e000446. https://doi.org/10.1136/bmjsem-2018-000446 (2018).
Google Scholar
Hora, M., Struška, M., Matějovská, Z., Kubový, P. & Sládek, V. Muscle activity during crouched walking. Am. J. Biol. Anthropol. https://doi.org/10.1002/ajpa.24834 (2023).
Google Scholar
Nakamura, M. et al. Relationship between changes in passive properties and muscle strength after static stretching. J. Bodyw. Mov. Ther. 28, 535–539. https://doi.org/10.1016/j.jbmt.2021.09.012 (2021).
Google Scholar
Brower, R. G. Consequences of bed rest. Crit. Care Med. 37, S422-428. https://doi.org/10.1097/CCM.0b013e3181b6e30a (2009).
Google Scholar
Penchev, R. et al. Back pain in outer space. Anesthesiology 135, 384–395. https://doi.org/10.1097/ALN.0000000000003812 (2021).
Google Scholar
Bailey, J. F. et al. From the international space station to the clinic: how prolonged unloading may disrupt lumbar spine stability. Spine J. 18, 7–14. https://doi.org/10.1016/j.spinee.2017.08.261 (2018).
Google Scholar
Plehuna, A. et al. Dry immersion induced acute low back pain and its relationship with trunk myofascial viscoelastic changes. Front. Physiol. 13, 1039924. https://doi.org/10.3389/fphys.2022.1039924 (2022).
Google Scholar
Green, D. A. & Scott, J. P. R. Spinal health during unloading and reloading associated with spaceflight. Front. Physiol. 8, 1126. https://doi.org/10.3389/fphys.2017.01126 (2017).
Google Scholar
Noonan, A. M. & Brown, S. H. M. Paraspinal muscle pathophysiology associated with low back pain and spine degenerative disorders. JOR Spine 4, e1171. https://doi.org/10.1002/jsp2.1171 (2021).
Google Scholar
Patel, Z. S. et al. Red risks for a journey to the red planet: The highest priority human health risks for a mission to Mars. NPJ Microgr. 6, 33. https://doi.org/10.1038/s41526-020-00124-6 (2020).
Google Scholar
Beaudart, C. et al. Assessment of muscle function and physical performance in daily clinical practice : A position paper endorsed by the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO). Calcif Tissue Int. 105, 1–14. https://doi.org/10.1007/s00223-019-00545-w (2019).
Google Scholar
Bailey, J. F. et al. Biomechanical changes in the lumbar spine following spaceflight and factors associated with postspaceflight disc herniation. Spine J. 22, 197–206. https://doi.org/10.1016/j.spinee.2021.07.021 (2022).
Google Scholar
Basti, A. et al. Diurnal variations in the expression of core-clock genes correlate with resting muscle properties and predict fluctuations in exercise performance across the day. BMJ Open Sport Exerc. Med. 7, e000876 (2021).
Google Scholar
Wu, Z. et al. Effects of age and sex on properties of lumbar erector spinae in healthy people: Preliminary results from a pilot study. Front. Physiol. 12, 718068 (2021).
Google Scholar
Marusiak, J., Jaskólska, A., Koszewicz, M., Budrewicz, S. & Jaskólski, A. Myometry revealed medication-induced decrease in resting skeletal muscle stiffness in Parkinson’s disease patients. Clin. Biomech. 27, 632–635 (2012).
Google Scholar
Agoriwo, M. W. et al. Feasibility and reliability of measuring muscle stiffness in Parkinson’s Disease using MyotonPRO device in a clinical setting in Ghana. Ghana Med. J. 56, 78–85 (2022).
Google Scholar
Gunga, H.-C. Human Physiology in Extreme Environments (Academic Press, 2020).
Qian, L. & Zhao, H. Nanoindentation of soft biological materials. Micromachines (Basel) 9, 654. https://doi.org/10.3390/mi9120654 (2018).
Google Scholar
