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Hinks A, Jacob K, Mashouri P, Medak KD, Franchi MV, Wright DC, Brown SHM, Power GA. Influence of weighted downhill running training on serial sarcomere number and work loop performance in the rat soleus. Biol Open 2022; 11:276077. [PMID: 35876382 PMCID: PMC9346294 DOI: 10.1242/bio.059491] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 06/23/2022] [Indexed: 12/16/2022] Open
Abstract
Increased serial sarcomere number (SSN) has been observed in rats following downhill running training due to the emphasis on active lengthening contractions; however, little is known about the influence on dynamic contractile function. Therefore, we employed 4 weeks of weighted downhill running training in rats, then assessed soleus SSN and work loop performance. We hypothesised trained rats would produce greater net work output during work loops due to a greater SSN. Thirty-one Sprague-Dawley rats were assigned to a training or sedentary control group. Weight was added during downhill running via a custom-made vest, progressing from 5–15% body mass. Following sacrifice, the soleus was dissected, and a force-length relationship was constructed. Work loops (cyclic muscle length changes) were then performed about optimal muscle length (LO) at 1.5–3-Hz cycle frequencies and 1–7-mm length changes. Muscles were then fixed in formalin at LO. Fascicle lengths and sarcomere lengths were measured to calculate SSN. Intramuscular collagen content and crosslinking were quantified via a hydroxyproline content and pepsin-solubility assay. Trained rats had longer fascicle lengths (+13%), greater SSN (+8%), and a less steep passive force-length curve than controls (P<0.05). There were no differences in collagen parameters (P>0.05). Net work output was greater (+78–209%) in trained than control rats for the 1.5-Hz work loops at 1 and 3-mm length changes (P<0.05), however, net work output was more related to maximum specific force (R2=0.17-0.48, P<0.05) than SSN (R2=0.03-0.07, P=0.17-0.86). Therefore, contrary to our hypothesis, training-induced sarcomerogenesis likely contributed little to the improvements in work loop performance. This article has an associated First Person interview with the first author of the paper. Summary: An investigation of adaptations in mechanical function induced by a novel method of weighted downhill running training in rats, and the connections to adaptations in muscle architecture.
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Affiliation(s)
- Avery Hinks
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Kaitlyn Jacob
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Parastoo Mashouri
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Kyle D Medak
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Martino V Franchi
- Department of Biomedical Sciences, Neuromuscular Physiology Laboratory, University of Padua, Padua 35122, Italy
| | - David C Wright
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada.,School of Kinesiology, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Stephen H M Brown
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Geoffrey A Power
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
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Hinks A, Franchi MV, Power GA. The influence of longitudinal muscle fascicle growth on mechanical function. J Appl Physiol (1985) 2022; 133:87-103. [DOI: 10.1152/japplphysiol.00114.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Skeletal muscle has the remarkable ability to remodel and adapt, such as the increase in serial sarcomere number (SSN) or fascicle length (FL) observed after overstretching a muscle. This type of remodelling is termed longitudinal muscle fascicle growth, and its impact on biomechanical function has been of interest since the 1960s due to its clinical applications in muscle strain injury, muscle spasticity, and sarcopenia. Despite simplified hypotheses on how longitudinal muscle fascicle growth might influence mechanical function, existing literature presents conflicting results partly due to a breadth of methodologies. The purpose of this review is to outline what is currently known about the influence of longitudinal muscle fascicle growth on mechanical function and suggest future directions to address current knowledge gaps and methodological limitations. Various interventions indicate longitudinal muscle fascicle growth can increase the optimal muscle length for active force, but whether the whole force-length relationship widens has been less investigated. Future research should also explore the ability for longitudinal fascicle growth to broaden the torque-angle relationship's plateau region, and the relation to increased force during shortening. Without a concurrent increase in intramuscular collagen, longitudinal muscle fascicle growth also reduces passive tension at long muscle lengths; further research is required to understand whether this translates to increased joint range of motion. Lastly, some evidence suggests longitudinal fascicle growth can increase maximum shortening velocity and peak isotonic power, however, there has yet to be direct assessment of these measures in a neurologically intact model of longitudinal muscle fascicle growth.
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Affiliation(s)
- Avery Hinks
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Martino V. Franchi
- Department of Biomedical Sciences,, University of Padua, Padova, Veneto, Italy
| | - Geoffrey A. Power
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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Labib M, Amirouche F, Pradhan S, Bobko A, Koh J. A Biomechanical Analysis of Shoulder Muscle Excursions During Abduction, After the Treatment of Massive Irreparable Rotator Cuff Tears Using Superior Capsular Reconstruction (SCR), Bursal Acromial Reconstruction (BAR), and SCR with BAR. J Shoulder Elb Arthroplast 2022; 6:24715492221109001. [PMID: 35782774 PMCID: PMC9240589 DOI: 10.1177/24715492221109001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 05/19/2022] [Accepted: 06/02/2022] [Indexed: 01/17/2023] Open
Abstract
Introduction Current understanding of the biomechanical effects of treatment options for irreparable rotator cuff (RC) tears is lacking. This study examines how shoulder muscle lengths and excursions are affected by superior capsular reconstruction (SCR), bursal acromial reconstruction (BAR), and SCR with BAR, following a complete supraspinatus tear. Method Six fresh-frozen cadaveric shoulders were examined. Deltoid and RC muscle lengths were measured at 0, 30, 45, 60, and 90° of shoulder abduction under six conditions: (1) intact, (2) partially torn supraspinatus, (3) completely torn supraspinatus, (4) SCR, (5) SCR with BAR, and (6) BAR. Muscle excursions from 0–90° of abduction were then calculated. Results Subscapularis muscle lengths after SCR, BAR, and SCR with BAR were significantly greater (post-hoc Tukey HSD test; p < .01) compared to the other conditions. Supraspinatus, infraspinatus, teres minor, and deltoid lengths were not significantly different (ANOVA test; p > .01) between the conditions. All muscle excursions remained statistically similar between the conditions (ANOVA test; p > .01). Conclusion These findings demonstrate that the use of SCR, BAR, or SCR with BAR for a complete supraspinatus tear, may increase subscapularis muscle length while maintaining other shoulder muscle lengths. An increase in subscapularis length can allow for more effective subscapularis muscle strengthening and increased compensatory function in the long term. Additionally, all shoulder muscle excursions are preserved after partial or complete supraspinatus tears and after SCR, BAR, or SCR with BAR. Therefore, these surgical treatments can initially normalize shoulder muscle function during 0–90° of abduction, after an irreparable supraspinatus tear.
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Affiliation(s)
- Michael Labib
- Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Farid Amirouche
- Department of Orthopaedics, University of Illinois, Chicago, IL, USA
- Department of Orthopaedics, NorthShore University HealthSystem, Evanston, IL, USA
| | - Sonia Pradhan
- Department of Orthopaedics, University of Illinois, Chicago, IL, USA
| | - Aimee Bobko
- Department of Orthopaedics, University of Illinois, Chicago, IL, USA
| | - Jason Koh
- Department of Orthopaedics, NorthShore University HealthSystem, Evanston, IL, USA
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Fukano M, Tsukahara Y, Takei S, Nose-Ogura S, Fujii T, Torii S. Recovery of Abdominal Muscle Thickness and Contractile Function in Women after Childbirth. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18042130. [PMID: 33671663 PMCID: PMC7926552 DOI: 10.3390/ijerph18042130] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 11/26/2022]
Abstract
Abdominal muscles may be both morphologically and functionally affected by pregnancy. Dysfunction of the muscles can lead to persistent postpartum low back pain. The recovery process of the abdominal muscles following childbirth is not well understood. This study aimed to demonstrate the changes in the thickness and contractile function of abdominal muscles during the first six months postpartum. Nine perinatal and 15 nulliparous females participated. The thicknesses and contraction/relaxation thickness ratios of the rectus abdominis (RA), external abdominal oblique (EO), internal abdominal oblique (IO), and transverse abdominis (TrA) were measured using ultrasound images from 36–39 weeks’ gestation until six months postpartum. The RA, IO, and TrA muscles were thinner in perinatal females than controls at 36–39 weeks of gestation (4.8 vs. 9.47 mm (RA), 5.45 vs. 7.73 mm (IO), 2.56 vs. 3.38 mm (TrA), respectively). The thinner IO muscle persisted for six months after delivery. The decreased TrA thickness ratio persisted until four months post-delivery. Abdominal muscle thickness and contractile function decreased in the postpartum period. Therefore, abdominal muscle exercises might help prevent postpartum symptoms; however, because deterioration of muscle function is significant in the first four months, careful attention should be paid to exercise intensity. The study limitation was a relatively small sample size, thus future studies should involve more participants.
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Affiliation(s)
- Mako Fukano
- College of Engineering, Shibaura Institute of Technology, Saitama 135-8548, Japan
- Faculty of Sport Sciences, Waseda University, Saitama 169-8050, Japan;
- Correspondence: ; Tel.: +81-48-720-6442
| | - Yuka Tsukahara
- Institute for Integrated Sports Medicine, Keio University School of Medicine, Tokyo 108-8345, Japan;
- Waseda Institute for Sport Sciences, Waseda University, Saitama 169-8050, Japan
| | - Seira Takei
- Orthopaedic Surgery, Sensory and Motor System Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 158-8557, Japan;
- Waseda Institute of Human Growth and Development, Waseda University, Saitama 169-8050, Japan
| | - Sayaka Nose-Ogura
- Department of Obstetrics and Gynecology, The University of Tokyo, Tokyo 158-8557, Japan; (S.N.-O.); (T.F.)
| | - Tomoyuki Fujii
- Department of Obstetrics and Gynecology, The University of Tokyo, Tokyo 158-8557, Japan; (S.N.-O.); (T.F.)
| | - Suguru Torii
- Faculty of Sport Sciences, Waseda University, Saitama 169-8050, Japan;
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Lieber RL, Roberts TJ, Blemker SS, Lee SSM, Herzog W. Skeletal muscle mechanics, energetics and plasticity. J Neuroeng Rehabil 2017; 14:108. [PMID: 29058612 PMCID: PMC5651624 DOI: 10.1186/s12984-017-0318-y] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 10/05/2017] [Indexed: 01/06/2023] Open
Abstract
The following papers by Richard Lieber (Skeletal Muscle as an Actuator), Thomas Roberts (Elastic Mechanisms and Muscle Function), Silvia Blemker (Skeletal Muscle has a Mind of its Own: a Computational Framework to Model the Complex Process of Muscle Adaptation) and Sabrina Lee (Muscle Properties of Spastic Muscle (Stroke and CP) are summaries of their representative contributions for the session on skeletal muscle mechanics, energetics and plasticity at the 2016 Biomechanics and Neural Control of Movement Conference (BANCOM 2016). Dr. Lieber revisits the topic of sarcomere length as a fundamental property of skeletal muscle contraction. Specifically, problems associated with sarcomere length non-uniformity and the role of sarcomerogenesis in diseases such as cerebral palsy are critically discussed. Dr. Roberts then makes us aware of the (often neglected) role of the passive tissues in muscles and discusses the properties of parallel elasticity and series elasticity, and their role in muscle function. Specifically, he identifies the merits of analyzing muscle deformations in three dimensions (rather than just two), because of the potential decoupling of the parallel elastic element length from the contractile element length, and reviews the associated implications for the architectural gear ratio of skeletal muscle contraction. Dr. Blemker then tackles muscle adaptation using a novel way of looking at adaptive processes and what might drive adaptation. She argues that cells do not have pre-programmed behaviors that are controlled by the nervous system. Rather, the adaptive responses of muscle fibers are determined by sub-cellular signaling pathways that are affected by mechanical and biochemical stimuli; an exciting framework with lots of potential. Finally, Dr. Lee takes on the challenging task of determining human muscle properties in vivo. She identifies the dilemma of how we can demonstrate the effectiveness of a treatment, specifically in cases of muscle spasticity following stroke or in children with cerebral palsy. She then discusses the merits of ultrasound based elastography, and the clinical possibilities this technique might hold. Overall, we are treated to a vast array of basic and clinical problems in skeletal muscle mechanics and physiology, with some solutions, and many suggestions for future research.
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Affiliation(s)
- Richard L Lieber
- Rehabilitation Institute of Chicago, Chicago, USA.,Northwestern University, Evanston, USA
| | | | | | | | - Walter Herzog
- University of Calgary, Faculty of Kinesiology, Calgary, Canada.
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Abstract
Understanding of the musculoskeletal system has evolved from the collection of individual phenomena in highly selected experimental preparations under highly controlled and often unphysiological conditions. At the systems level, it is now possible to construct complete and reasonably accurate models of the kinetics and energetics of realistic muscles and to combine them to understand the dynamics of complete musculoskeletal systems performing natural behaviors. At the reductionist level, it is possible to relate most of the individual phenomena to the anatomical structures and biochemical processes that account for them. Two large challenges remain. At a systems level, neuroscience must now account for how the nervous system learns to exploit the many complex features that evolution has incorporated into muscle and limb mechanics. At a reductionist level, medicine must now account for the many forms of pathology and disability that arise from the many diseases and injuries to which this highly evolved system is inevitably prone. © 2017 American Physiological Society. Compr Physiol 7:429-462, 2017.
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Affiliation(s)
| | - Gerald E Loeb
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
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O'Connor SM, Cheng EJ, Young KW, Ward SR, Lieber RL. Quantification of sarcomere length distribution in whole muscle frozen sections. ACTA ACUST UNITED AC 2016; 219:1432-6. [PMID: 26994184 DOI: 10.1242/jeb.132084] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 03/02/2016] [Indexed: 01/04/2023]
Abstract
Laser diffraction (LD) is a valuable tool for measuring sarcomere length (Ls), a major determinant of muscle function. However, this method relies on few measurements per sample that are often extrapolated to whole muscle properties. Currently it is not possible to measure Ls throughout an entire muscle and determine how Ls varies at this scale. To address this issue, we developed an actuated LD scanner for sampling large numbers of sarcomeres in thick whole muscle longitudinal sections. Sections of high optical quality and fixation were produced from tibialis anterior and extensor digitorum longus muscles of Sprague-Dawley rats (N=6). Scans produced two-dimensional Ls maps, capturing >85% of the muscle area per section. Individual Ls measures generated by automatic LD and bright-field microscopy showed excellent agreement over a large Ls range (ICC>0.93). Two-dimensional maps also revealed prominent regional Ls variations across muscles.
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Affiliation(s)
- Shawn M O'Connor
- Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA Department of Orthopaedic Surgery, University of California San Diego, La Jolla, CA 92093, USA
| | - Elton J Cheng
- Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Kevin W Young
- Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA Research Service, Veteran's Administration San Diego Healthcare System, San Diego, CA 92161, USA
| | - Samuel R Ward
- Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA Department of Orthopaedic Surgery, University of California San Diego, La Jolla, CA 92093, USA Research Service, Veteran's Administration San Diego Healthcare System, San Diego, CA 92161, USA Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA
| | - Richard L Lieber
- Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA Department of Orthopaedic Surgery, University of California San Diego, La Jolla, CA 92093, USA Research Service, Veteran's Administration San Diego Healthcare System, San Diego, CA 92161, USA Rehabilitation Institute of Chicago, Chicago, IL 60611, USA
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Osteotomy of the greater trochanter: effect on gluteus medius function. Surg Radiol Anat 2015; 37:599-607. [PMID: 25828839 DOI: 10.1007/s00276-015-1466-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 03/20/2015] [Indexed: 10/23/2022]
Abstract
PURPOSE Advancement of the greater trochanter alters the function of the gluteus medius muscle. However, with the exception of clinical studies and biomechanical lever arm studies, no publications that analyze the consequences of advancement of the greater trochanter on the muscle function exist. The aim of the study was to analyze the mechanical changes of gluteus medius after osteotomy of the greater trochanter in a lab setting. METHODS An anatomical study of origin and insertion of the gluteus medius was carried out on four hips. Based on the dissections, a string model was developed dividing the muscle into five sectors. Changes in muscle fiber length were measured for every 10° of flexion, internal and external rotation and abduction with the trochanter in anatomic, proximalized and distalized positions. RESULTS Distalization of the trochanter leads to an imbalance of muscle action, moving the isometric sector of the muscle anteriorly with more muscle sectors being active during flexion and less during extension. Stretching of the muscle increases passive forces but decreases the force generation capacity of the muscle and at the same time increased muscle fiber excursion may require more energy consumption, which may explain earlier fatigue of the abductor musculature after distalization of the trochanter. For abduction, distalization of the muscle attachment leads to a change in contraction pattern from isometric to isotonic. Optimal balancing and excursion of the muscle is when the tip of the greater trochanter is at level with the hip rotation center. CONCLUSIONS In hips with high riding trochanter, the optimal position is at the level of the center of hip rotation. Excessive distalization should be avoided. As the conclusions and considerations are based on a lab setting, transfer to clinical practice may not necessarily apply.
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Huijing PA, Maas H. Adaptation of physiological cross-sectional area and serial number of sarcomeres after tendon transfer of rat muscle. Scand J Med Sci Sports 2015; 26:244-55. [PMID: 25693427 DOI: 10.1111/sms.12431] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2015] [Indexed: 12/24/2022]
Abstract
Tendon transfer surgery to a new extensor insertion was performed for musculus flexor carpi ulnaris (FCU) of young adult rats, after which animals were allowed to recover. Mechanical properties and adaptive effects on body mass, bone growth, serial number of sarcomeres, and muscle physiological cross-sectional area were studied. Between the transfer and control groups, no differences were found for body mass and forearm length growth. In contrast, transferred muscles had a 19% smaller physiological cross-sectional area and 25% fewer sarcomeres in series within its muscle fibers than control muscles, i.e., a deficit in muscle belly growth is present. Our present results confirm our the length of previous work showing a limited capability of changing the adapted transferred FCU muscle belly, as the muscle-tendon complex is stretched, so that most of the acute FCU length change must originate from the tendon. This should most likely be attributed to surgery-related additional and/or altered connective tissue linkages at the muscle-tendon boundary. The substantially increased FCU tendon length found, after recovery from surgery and adaptation to the conditions of the transferred position, is likely to be related to such enhanced stretching of the FCU tendon.
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Affiliation(s)
- P A Huijing
- MOVE Research Institute Amsterdam, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, The Netherlands
| | - H Maas
- MOVE Research Institute Amsterdam, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, The Netherlands
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Garg K, Ward CL, Hurtgen BJ, Wilken JM, Stinner DJ, Wenke JC, Owens JG, Corona BT. Volumetric muscle loss: persistent functional deficits beyond frank loss of tissue. J Orthop Res 2015; 33:40-6. [PMID: 25231205 DOI: 10.1002/jor.22730] [Citation(s) in RCA: 147] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 08/08/2014] [Indexed: 02/04/2023]
Abstract
Open fracture is a common occurrence in civilian and military populations. Though great strides have been made in limb salvage efforts, persistent muscle strength deficits can contribute to a diminished limb function after the bone has healed. Over the past decade, a growing effort to establish therapies directed at de novo muscle regeneration has produced several therapeutic approaches. As this effort progresses and as therapies reach clinical testing, many questions remain regarding the pathophysiology of the volumetric loss of skeletal muscle. The current study demonstrates, in a rat "open fracture" model, that the volumetric loss of skeletal muscle results in persistent functional deficits that are dependent on muscle length and joint angle. Moreover, the injured muscle has an increased stiffness during passive stretch and a reduced functional excursion. A case study of a patient with an open type III tibia fracture resulting in volumetric muscle loss in the anterior and posterior compartment is also presented. Eighteen months after injury and tibia healing, persistent functional deficits are apparent with many of the same qualities demonstrated in the animal model. Muscle architectural adaptations likely underlie the altered intrinsic functional characteristics of the remaining musculature.
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Affiliation(s)
- Koyal Garg
- US Army Institute of Surgical Research, Extremity Trauma and Regenerative Medicine, Joint Base Fort Sam Houston, Texas
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11
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Snoeck O, Beyer B, Feipel V, Salvia P, Sterckx JL, Rooze M, Van Sint Jan S. Tendon and fascial structure contributions to knee muscle excursions and knee joint displacement. Clin Biomech (Bristol, Avon) 2014; 29:1070-6. [PMID: 25168083 DOI: 10.1016/j.clinbiomech.2014.08.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 08/07/2014] [Accepted: 08/07/2014] [Indexed: 02/07/2023]
Abstract
BACKGROUND Semitendinosus and gracilis muscles whose tendons are used in surgical reconstruction of the anterior cruciate ligament maintain their contractile ability, and a limited decrease of hamstring muscles force is observed postoperatively despite important changes. The goal was to quantify the influence of the myofascial structures on excursions and moment arms of knee muscles to attempt explaining the above-mentioned post-surgical observations. METHODS Hamstring harvesting procedures were performed by a senior orthopaedic surgeon on seven lower limbs from fresh-frozen specimens. Femoro-tibial kinematics and tendons excursion were simultaneously recorded at each steps of the surgery. FINDINGS No significant difference was demonstrated for excursions and moment arms after tenotomies and gracilis tendon harvesting (P≥0.05). The first significant semitendinosus excursion (P<1.17×10(-4)) and moment arm (P<6.88×10(-5)) decrease was observed after semitendinosus tendon harvesting (46% of the initial excursion). INTERPRETATION Gracilis and semitendinosus myofascial pathway is crucial for force transmission towards the knee joint.
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Affiliation(s)
- O Snoeck
- Laboratory of Anatomy, Biomechanics and Organogenesis, Université Libre de Bruxelles (ULB), Bruxelles, Belgium.
| | - B Beyer
- Laboratory of Anatomy, Biomechanics and Organogenesis, Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - V Feipel
- Laboratory of Anatomy, Biomechanics and Organogenesis, Université Libre de Bruxelles (ULB), Bruxelles, Belgium; Laboratory of Functional Anatomy, Université Libre de Bruxelles, Bruxelles, Belgium
| | - P Salvia
- Laboratory of Anatomy, Biomechanics and Organogenesis, Université Libre de Bruxelles (ULB), Bruxelles, Belgium; Laboratory of Functional Anatomy, Université Libre de Bruxelles, Bruxelles, Belgium
| | - J-L Sterckx
- Laboratory of Functional Anatomy, Université Libre de Bruxelles, Bruxelles, Belgium
| | - M Rooze
- Laboratory of Anatomy, Biomechanics and Organogenesis, Université Libre de Bruxelles (ULB), Bruxelles, Belgium; Laboratory of Functional Anatomy, Université Libre de Bruxelles, Bruxelles, Belgium; Department of Orthopedic Surgery, Erasme Hospital, Université Libre de Bruxelles, Bruxelles, Belgium
| | - S Van Sint Jan
- Laboratory of Anatomy, Biomechanics and Organogenesis, Université Libre de Bruxelles (ULB), Bruxelles, Belgium
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Lieber RL, Ward SR. Cellular mechanisms of tissue fibrosis. 4. Structural and functional consequences of skeletal muscle fibrosis. Am J Physiol Cell Physiol 2013; 305:C241-52. [PMID: 23761627 DOI: 10.1152/ajpcell.00173.2013] [Citation(s) in RCA: 214] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Skeletal muscle fibrosis can be a devastating clinical problem that arises from many causes, including primary skeletal muscle tissue diseases, as seen in the muscular dystrophies, or it can be secondary to events that include trauma to muscle or brain injury. The cellular source of activated fibroblasts (myofibroblasts) may include resident fibroblasts, adult muscle stem cells, or inflammatory or perivascular cells, depending on the model studied. Even though it is likely that there is no single source for all myofibroblasts, a common mechanism for the production of fibrosis is via the transforming growth factor-β/phosphorylated Smad3 pathway. This pathway and its downstream targets thus provide loci for antifibrotic therapies, as do methods for blocking the transdifferentiation of progenitors into activated fibroblasts. A structural model for the extracellular collagen network of skeletal muscle is needed so that measurements of collagen content, morphology, and gene expression can be related to mechanical properties. Approaches used to study fibrosis in tissues, such as lung, kidney, and liver, need to be applied to studies of skeletal muscle to identify ways to prevent or even cure the devastating maladies of skeletal muscle.
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Affiliation(s)
- Richard L Lieber
- Department of Orthopaedic Surgery, University of California San Diego, San Diego, California 92093-0863, USA.
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