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Shah PK, Stevens JE, Gregory CM, Pathare NC, Jayaraman A, Bickel SC, Bowden M, Behrman AL, Walter GA, Dudley GA, Vandenborne K. Lower-extremity muscle cross-sectional area after incomplete spinal cord injury. Arch Phys Med Rehabil 2006; 87:772-8. [PMID: 16731211 DOI: 10.1016/j.apmr.2006.02.028] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2005] [Accepted: 02/19/2006] [Indexed: 12/25/2022]
Abstract
OBJECTIVES (1) To quantify skeletal muscle size in lower-extremity muscles of people after incomplete spinal cord injury (SCI), (2) to assess differences in muscle size between involved lower limbs, (3) to determine the impact of ambulatory status (using wheelchair for community mobility vs not using a wheelchair for community mobility) on muscle size after incomplete SCI, and (4) to determine if differential atrophy occurs among individual muscles after incomplete SCI. DESIGN Case-control study. SETTING University research setting. PARTICIPANTS Seventeen people with incomplete SCI and 17 age-, sex-, weight-, and height-matched noninjured controls. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Maximum cross-sectional area (CSA) of individual lower-extremity muscles (soleus, medial gastrocnemius, lateral gastrocnemius, tibialis anterior, quadriceps femoris, hamstrings) as assessed by magnetic resonance imaging. RESULTS Overall, subjects with incomplete SCI had significantly smaller (24%-31%) average muscle CSA in affected lower-extremity muscles as compared with control subjects (P<.05). Mean differences were highest in the thigh muscles ( approximately 31%) compared with the lower-leg muscles ( approximately 25%). No differences were noted between the self-reported more- and less-involved limbs within the incomplete SCI group. Dichotomizing the incomplete SCI group showed significantly lower muscle CSA values in both the wheelchair (range, 21%-39%) and nonwheelchair groups (range, 24%-38%). In addition, the wheelchair group exhibited significantly greater plantarflexor muscle atrophy compared with the dorsiflexors, with maximum atrophy in the medial gastrocnemius muscle (39%). CONCLUSIONS Our results suggest marked and differential atrophic response of the affected lower-extremity muscles that is seemingly affected by ambulatory status in people with incomplete SCI.
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Liu M, Stevens JE, Bose P, Thompson FJ, Oʼsteen W, Walter GA, Anderson DK, Vandenborne K, White LJ. The Effect of Treadmill Training on IGF-I Expression in Skeletal Muscle Following Spinal Cord Injury. Med Sci Sports Exerc 2006. [DOI: 10.1249/00005768-200605001-01149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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128
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Gregory C, Mahoney E, Bickel CS, Chen YW, Dudley G, Vandenborne K. Molecular Signature Associated with Improvements in Muscle Mass and Glucose Tolerance after Spinal Cord Injury. Med Sci Sports Exerc 2006. [DOI: 10.1249/00005768-200605001-03150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Stevens JE, Borst SE, Li Y, Conover CF, Sweeney HL, Walter GA, Vandenborne K, White LJ. Insulin-like Growth Factor-1 Gene Transfer Augments Muscle IGF Protein Content Despite Cast Immobilization. Med Sci Sports Exerc 2006. [DOI: 10.1249/00005768-200605001-01111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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130
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Vandenborne K, Gregory CM, Walter GA, Shi R, Scarborough MT, Chen YW, White LJ. Molecular Signatures Associated with Skeletal Muscle Disuse Atrophy in Humans. Med Sci Sports Exerc 2006. [DOI: 10.1249/00005768-200605001-01112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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131
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Shah PK, Stevens JE, Gregory CM, Pathare NC, Jayaraman A, Bickel CS, Bowden M, Behrman AL, Dudley GA, Walter GA, Vandenborne K. Skeletal Muscle Morphology after Incomplete Spinal Cord Injury. Med Sci Sports Exerc 2006. [DOI: 10.1249/00005768-200605001-01108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Liu M, Bose P, Walter GA, Anderson DK, Thompson FJ, Vandenborne K. Changes in muscle T2 relaxation properties following spinal cord injury and locomotor training. Eur J Appl Physiol 2006; 97:355-61. [PMID: 16770473 DOI: 10.1007/s00421-006-0199-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/27/2006] [Indexed: 11/25/2022]
Abstract
Magnetic resonance (MR) is frequently used to study structural and biochemical properties of skeletal muscle. Changes in proton transverse relaxation (T2) properties have been used to study muscle cellular damage, as well as muscle activation during exercise protocols. In this study, we implemented MR imaging to characterize the T2 relaxation properties of rat hindlimb muscles following spinal cord injury (SCI) and locomotor training. After moderate midthoracic contusion SCI, Sprague-Dawley rats were assigned to either treadmill training, cycle training or an untrained group. T2 weighted images were obtained and mean muscle T2 times were calculated in the tibialis anterior, soleus, and gastrocnemius (GAS) muscles at pre-injury as well as at 1, 2, 4, 8, and 12 weeks post-injury. Following SCI, hindlimb muscles in untrained animals showed a significant increase in muscle T2, with the most dramatic shift (+5.46 ms) observed in soleus muscle at 1 week post-SCI. Subsequently, all muscle groups showed a spontaneous recovery in muscle T2 with normalized T2 values in the GAS and tibilias anterior muscles at 4 weeks and the soleus at 12 weeks post-SCI. Both training paradigms, treadmill and cycling training, accelerated the recovery of soleus muscle T2. As a result, soleus muscle T2 recovered back to pre-injury values within 3 weeks of training in both training groups. Finally, in vitro histological assessments of rat skeletal muscles demonstrated that there was no apparent muscle injury in any of the muscles studied at 1 week post-SCI.
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Ilfeld BM, Wright TW, Enneking KF, Vandenborne K. Total Elbow Arthroplasty as an Outpatient Procedure Using a Continuous Infraclavicular Nerve Block at Home. Reg Anesth Pain Med 2006. [DOI: 10.1097/00115550-200603000-00012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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134
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Ilfeld BM, Gearen PF, Enneking FK, Berry LF, Spadoni EH, George SZ, Vandenborne K. Total Knee Arthroplasty as an Overnight-Stay Procedure Using Continuous Femoral Nerve Blocks at Home: A Prospective Feasibility Study. Anesth Analg 2006; 102:87-90. [PMID: 16368810 DOI: 10.1213/01.ane.0000189562.86969.9f] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The average duration of hospitalization after total knee arthroplasty (TKA) in the United States is 4-5 days. In this two-phase study we investigated the feasibility of converting TKA into an overnight-stay procedure using a continuous femoral nerve block provided at home through postoperative day 4. Nine of 10 patients met discharge criteria and were discharged home the day after surgery. Pain was well controlled, opioid requirements and sleep disturbances were minimal, and patient satisfaction was high. Additional research is required to replicate these results in a controlled trial, define the appropriate subset of patients, and assess the incidence of complications associated with this practice before its mainstream use.
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Jayaraman A, Gregory CM, Bowden M, Stevens JE, Shah P, Behrman AL, Vandenborne K. Lower extremity skeletal muscle function in persons with incomplete spinal cord injury. Spinal Cord 2005; 44:680-7. [PMID: 16344848 DOI: 10.1038/sj.sc.3101892] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
STUDY DESIGN A cross-sectional study design. OBJECTIVES To characterize and specifically quantify impairments in muscle function after chronic incomplete spinal cord injury (SCI). SETTING University of Florida, Gainesville, FL, USA. METHODS Voluntary and electrically elicited contractile measurements were performed and voluntary activation deficits were quantitatively determined in the knee extensor and ankle plantar flexor muscle groups in 10 individuals with chronic incomplete SCI (C5-T8, ASIA C or D) and age-, gender-, height- and body weight matched healthy controls. RESULTS Persons with incomplete-SCI were able to produce only 36 and 24% of the knee extensor torque and 38 and 26% of the plantar flexor torque generated by noninjured controls in the self-reported less-involved and more-involved limbs, respectively (P<0.05). In addition, both indices of explosive or instantaneous muscle strength, torque200 (absolute torque reached at 200 ms) and the average rate of torque development (ARTD) were dramatically reduced in the ankle plantar flexor and knee extensor muscle groups in persons with incomplete-SCI. However, the deficit in instantaneous muscle strength was most pronounced in the ankle plantar flexor muscles, with an 11.7-fold difference between the torque200 measured in the self-reported more involved limb and a 5-fold difference in the less-involved limb compared to control muscles. Voluntary activation deficits ranged between 42 and 66% in both muscle groups. Interestingly, electrically elicited contractile properties did not differ between the groups. CONCLUSION The resultant impact of incomplete-SCI is that affected muscles not only become weak, but slow to develop voluntary torque. We speculate that the large deficit in torque200 and ARTD in the ankle plantar flexors muscles of persons with incomplete-SCI may limit locomotor function. The results presented in this study provide a quantitative and sensitive assessment of muscle function upon which future research examining rehabilitation programs aimed at restoring muscle function and promoting functional recovery after incomplete-SCI may be based.
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Frimel TN, Walter GA, Gibbs JD, Gaidosh GS, Vandenborne K. Noninvasive monitoring of muscle damage during reloading following limb disuse. Muscle Nerve 2005; 32:605-12. [PMID: 16003743 DOI: 10.1002/mus.20398] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Cast immobilization causes skeletal muscle disuse atrophy and an increased susceptibility to muscle damage. The objective of this study was to explore the utility of noninvasive magnetic resonance (MR) imaging to monitor muscle damage in the lower hindlimb muscles of the mouse during reloading following cast immobilization and to compare the findings in different muscles. The hindlimbs of C57BL6 mice were immobilized for 2 weeks in plantarflexion using a bilateral casting model. Following immobilization the mice were allowed to reambulate and muscle damage was monitored at different times. Cage-restricted reloading following cast immobilization induced a significant shift (P < 0.0001) in the transverse (T2) relaxation characteristics of the postural slow-twitch soleus muscle, but not in the neighboring gastrocnemius. Soleus T2 values peaked at 2 days of reloading. Muscle-specific changes in MR T2 relaxation properties correlated with uptake of Evans blue dye, a histological marker of muscle damage. This study demonstrates that T2 MR imaging can be implemented to monitor noninvasively and sequentially muscle-specific damage during reloading following limb disuse.
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Ilfeld BM, Wright TW, Enneking FK, Mace JA, Shuster JJ, Spadoni EH, Chmielewski TL, Vandenborne K. Total shoulder arthroplasty as an outpatient procedure using ambulatory perineural local anesthetic infusion: a pilot feasibility study. Anesth Analg 2005; 101:1319-1322. [PMID: 16243987 DOI: 10.1213/01.ane.0000180199.52383.ce] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We investigated the feasibility of converting total shoulder arthroplasty (TSA) into an outpatient procedure using ambulatory interscalene perineural ropivacaine infusion. Of the patients of the first phase (n = 8) who were required to remain hospitalized for at least 1 postoperative night, 5 met discharge criteria in the recovery room. Of the subsequent patients of the second phase (n = 6), all met discharge criteria in the recovery room after surgery, and 5 were discharged directly home. For all patients, postoperative pain was well controlled, oral opioid requirements and sleep disturbances were minimal, range-of-motion consistently reached or exceeded the surgeon's expectations, and patient satisfaction was high. These results suggest that TSA may be performed on an outpatient basis using perineural local anesthetic infusion. Additional research is required to define the appropriate subset of patients and assess the incidence of complications associated with this practice before its mainstream use.
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Gregory CM, Williams RH, Vandenborne K, Dudley GA. Metabolic and phenotypic characteristics of human skeletal muscle fibers as predictors of glycogen utilization during electrical stimulation. Eur J Appl Physiol 2005; 95:276-82. [PMID: 16096841 DOI: 10.1007/s00421-005-0003-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/18/2005] [Indexed: 11/27/2022]
Abstract
Characteristics of skeletal muscle such as fiber type composition and activities of key metabolic enzymes have been purported to affect glycogen utilization. However, the relative importance individual factors may have in predicting glycogen utilization of individual muscle fibers has not been addressed. Thus, we sought to determine the relative importance that metabolic characteristics and phenotypic expression of individual fibers have in predicting fiber specific glycogen utilization during neuromuscular electrical stimulation (NMES) exercise. Biopsies were taken from the m, vastus lateralis (VL) of eight recreationally active males before and immediately after 30 min of non-fatiguing NMES and analyzed for type (I, IIa and IIx), succinate dehydrogenase activity (SDH), glycerol-phosphate dehydrogenase activity (GPDH), quantitative-actomyosin adenosine triphosphatase activity (qATPase), and glycogen content. Our results demonstrate that a ratio of enzyme activities representing pathways for energy supply and energy demand (SDH: qATPase) accounted for more of the variance in glycogen utilization (y=0.2091 e(-0.0329x ), R2=0.622, P< or = 0.0001) than SDH (R2=0.321) or qATPase (R2=0.365) alone. Fiber phenotype was also a significant predictor of glycogen utilization, but to a lesser extent than the other variables studied (R2=0.201). A ratio of the activities of enzymes representing pathways of energy supply and energy demand, represented by SDH:qATPase, is a better predictor of glycogen utilization than either of its components independently while fiber phenotype, although a statistically significant predictor of glycogen utilization, may not be the most appropriate determinate of the functional characteristics of an individual fiber.
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Pathare NC, Stevens JE, Walter GA, Scarborough MT, Shah P, Jayaraman A, Gibbs CP, Vandenborne K. Disuse Versus Reloading Induced Change In Energy Rich Phosphate Content In Human Skeletal Muscle. Med Sci Sports Exerc 2005. [DOI: 10.1097/00005768-200505001-02293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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140
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Jayaraman A, Shah P, Gregory C, Stevens J, Bowden M, Behrman A, Walter G, Vandenborne K. Mechanisms Of Muscle Dysfunction In Persons After Incomplete Spinal Cord Injury. Med Sci Sports Exerc 2005. [DOI: 10.1249/00005768-200505001-00191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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141
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Stevens JE, Yarasheski KE, Li Y, Sweeney HL, Vandenborne K. Insulin-like Growth Factor-1 Gene Transfer Augments Muscle Protein Synthesis Rate And Size In Adult Mice. Med Sci Sports Exerc 2005. [DOI: 10.1249/00005768-200505001-00405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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142
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Liu M, Bose P, Thompson F, Walter G, Anderson D, Vandenborne K. Changes In Soleus Myosin Heavy Chain Expression In Response To Training Following Spinal Cord Injury. Med Sci Sports Exerc 2005. [DOI: 10.1249/00005768-200505001-00192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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143
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Mizner RL, Petterson SC, Stevens JE, Vandenborne K, Snyder-Mackler L. Early quadriceps strength loss after total knee arthroplasty. The contributions of muscle atrophy and failure of voluntary muscle activation. J Bone Joint Surg Am 2005; 87:1047-53. [PMID: 15866968 PMCID: PMC1167681 DOI: 10.2106/jbjs.d.01992] [Citation(s) in RCA: 285] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND While total knee arthroplasty reduces pain and provides a functional range of motion of the knee, quadriceps weakness and reduced functional capacity typically are still present one year after surgery. The purpose of the present investigation was to determine the role of failure of voluntary muscle activation and muscle atrophy in the early loss of quadriceps strength after surgery. METHODS Twenty patients with unilateral knee osteoarthritis were tested an average of ten days before and twenty-seven days after primary total knee arthroplasty. Quadriceps strength and voluntary muscle activation were measured with use of a burst-superimposition technique in which a supramaximal burst of electrical stimulation is superimposed on a maximum voluntary isometric contraction. Maximal quadriceps cross-sectional area was assessed with use of magnetic resonance imaging. RESULTS Postoperatively, quadriceps strength was decreased by 62%, voluntary activation was decreased by 17%, and maximal cross-sectional area was decreased by 10% in comparison with the preoperative values; these differences were significant (p < 0.01). Collectively, failure of voluntary muscle activation and atrophy explained 85% of the loss of quadriceps strength (p < 0.001). Multiple linear regression analysis revealed that failure of voluntary activation contributed nearly twice as much as atrophy did to the loss of quadriceps strength. The severity of knee pain with muscle contraction did not change significantly compared with the preoperative level (p = 0.31). Changes in knee pain during strength-testing did not account for a significant amount of the change in voluntary activation (p = 0.14). CONCLUSIONS Patients who are managed with total knee arthroplasty have profound impairment of quadriceps strength one month after surgery. This impairment is predominantly due to failure of voluntary muscle activation, and it is also influenced, to a lesser degree, by muscle atrophy. Knee pain with muscle contraction played a surprisingly small role in the reduction of muscle activation.
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Frimel T, Kapadia F, Gaidosh G, Le Y, Walter G, Gregory C, Vandenborne K. A Translational Model Of Disuse Atrophy In The Mouse Hind-limb Using Cast Immobilization. Med Sci Sports Exerc 2005. [DOI: 10.1249/00005768-200505001-00181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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145
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Pathare NC, Stevens JE, Walter GA, Scarborough MT, Shah P, Jayaraman A, Gibbs CP, Vandenborne K. Disuse Versus Reloading Induced Change In Energy Rich Phosphate Content In Human Skeletal Muscle. Med Sci Sports Exerc 2005. [DOI: 10.1249/00005768-200505001-02293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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146
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Gregory C, Jayaraman A, Bowden M, Behrman A, Vandenborne K. Resistance Training And Muscle Function In Persons After Incomplete Spinal Cord Injury. Med Sci Sports Exerc 2005. [DOI: 10.1249/00005768-200505001-00189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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147
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Frimel TN, Kapadia F, Gaidosh GS, Li Y, Walter GA, Vandenborne K. A model of muscle atrophy using cast immobilization in mice. Muscle Nerve 2005; 32:672-4. [PMID: 16025524 DOI: 10.1002/mus.20399] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We describe a new cast-immobilization protocol to induce muscle atrophy in the lower hindlimb muscles of mice. Bilateral cast immobilization for 2 weeks in a shortened position resulted in a significant loss of muscle size and strength in the soleus and extensor digitorum longus. The availability of a model of cast immobilization in mice may benefit future studies targeting genetic or cell therapy interventions of muscle atrophy in transgenic and mutant mice strains.
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Stevens JE, Walter GA, Okereke E, Scarborough MT, Esterhai JL, George SZ, Kelley MJ, Tillman SM, Gibbs JD, Elliott MA, Frimel TN, Gibbs CP, Vandenborne K. Muscle Adaptations with Immobilization and Rehabilitation after Ankle Fracture. Med Sci Sports Exerc 2004; 36:1695-701. [PMID: 15595289 DOI: 10.1249/01.mss.0000142407.25188.05] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
UNLABELLED INTRODUCTION/ PURPOSE: The widespread occurrence of muscular atrophy during immobilization and its reversal presents an important challenge to rehabilitation medicine. We used 3D-magnetic resonance imaging (MRI) in patients with surgically-stabilized ankle mortise fractures to quantify changes in plantarflexor and dorsiflexor muscle size during immobilization and rehabilitation, as well as to evaluate changes in force generating capacity (specific torque). METHODS Twenty-individuals participated in a 10 wk rehabilitation program after 7 wk of immobilization. MRIs were acquired at baseline, 2, and 7 wk of immobilization, and at 5 and 10 wk of rehabilitation. Isometric plantarflexor muscle strength testing was performed at 0, 5, and 10 wk of rehabilitation. RESULTS Dorsiflexors and plantarflexors atrophied 18.9% and 24.4% respectively, the majority of which occurred during the first 2 wk of immobilization (dorsiflexors: 9.6%; plantarflexors: 14.1%). Likewise, more than 50% of hypertrophy during rehabilitation occurred within the first 5 wk of rehabilitation for both the dorsiflexors (12.9%) and plantarflexors (13.2%), when compared to the total amount of hypertrophy over 10 wk of rehabilitation (dorsiflexors: 17.6%, plantarflexors: 22.5%). There were no significant differences in hypertrophy or atrophy of the dorsiflexor or plantarflexor muscles, despite a rehabilitation emphasis on the plantarflexors. Patients had significantly lower plantarflexor specific torque (torque/CSA) than healthy, control subjects immediately after cast immobilization, which did not return to normal after 10 wk of rehabilitation (P < 0.05). CONCLUSION Our investigation of the consequences of limb immobilization on rehabilitation outcomes in patients can be applied directly to optimizing rehabilitation programs. Although muscle hypertrophy occurred early during rehabilitation, plantarflexor muscle function (specific torque) should remain the focus of rehabilitation programs because although CSA recovered quickly, specific torque still lagged behind that of control subjects.
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Pathare N, Walter GA, Stevens JE, Yang Z, Okerke E, Gibbs JD, Esterhai JL, Scarborough MT, Gibbs CP, Sweeney HL, Vandenborne K. Changes in inorganic phosphate and force production in human skeletal muscle after cast immobilization. J Appl Physiol (1985) 2004; 98:307-14. [PMID: 15333614 DOI: 10.1152/japplphysiol.00612.2004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cast immobilization is associated with decreases in muscle contractile area, specific force, and functional ability. The pathophysiological processes underlying the loss of specific force production as well as the role of metabolic alterations are not well understood. The aim of this study was to quantify changes in the resting energy-rich phosphate content and specific force production after immobilization. (31)P-magnetic resonance spectroscopy, three-dimensional magnetic resonance imaging, and isometric strength testing were performed in healthy subjects and patients with an ankle fracture after 7 wk of immobilization and during rehabilitation. Muscle biopsies were obtained in a subset of patients. After immobilization, there was a significant decrease in the specific plantar flexor torque and a significant increase in the inorganic phosphate (P(i)) concentration (P < 0.001) and the P(i)-to-phosphocreatine (PCr) ratio (P < 0.001). No significant change in the PCr content or basal pH was noted. During rehabilitation, both the P(i) content and the P(i)-to-PCr ratio decreased and specific torque increased, approaching control values after 10 wk of rehabilitation. Regression analysis showed an inverse relationship between the in vivo P(i) concentration and specific torque (r = 0.65, P < 0.01). In vitro force mechanics performed on skinned human muscle fibers demonstrated that varying the P(i) levels within the ranges observed across individuals in vivo (4-10 mM) changed force production by approximately 16%. In summary, our findings clearly depict a change in the resting energy-rich phosphate content of skeletal muscle with immobilization, which may negatively impact its force generation.
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Pathare NC, Stevens JE, Walter GA, Scarborough MT, Tillman SM, Gibbs JD, Elliot MA, Gibbs CP, Vandenborne K. Muscle Contractile Area and Phosphate Metabolite Contributions to Torque De. cits after Limb Disuse. Med Sci Sports Exerc 2004. [DOI: 10.1097/00005768-200405001-00421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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