Sarcomere lengths in human extensor carpi radialis brevis measured by microendoscopy
Melinda J. Cromie PhD
Department of Mechanical Engineering, Stanford University, Stanford, California, USA
Search for more papers by this authorGabriel N. Sanchez PhD
Department of Mechanical Engineering, Stanford University, Stanford, California, USA
Search for more papers by this authorMark J. Schnitzer PhD
Departments of Applied Physics and Biology, Howard Hughes Medical Institute, Stanford University, Stanford, California, USA
Search for more papers by this authorCorresponding Author
Scott L. Delp PhD
Department of Mechanical Engineering, Stanford University, Stanford, California, USA
Department of Bioengineering, Stanford University, 318 Campus Drive, Room S321, James H. Clark Center, MC 5454, Stanford, California, 94305-5454 USA
Correspondence to: S.L. Delp; e-mail: [email protected]Search for more papers by this authorMelinda J. Cromie PhD
Department of Mechanical Engineering, Stanford University, Stanford, California, USA
Search for more papers by this authorGabriel N. Sanchez PhD
Department of Mechanical Engineering, Stanford University, Stanford, California, USA
Search for more papers by this authorMark J. Schnitzer PhD
Departments of Applied Physics and Biology, Howard Hughes Medical Institute, Stanford University, Stanford, California, USA
Search for more papers by this authorCorresponding Author
Scott L. Delp PhD
Department of Mechanical Engineering, Stanford University, Stanford, California, USA
Department of Bioengineering, Stanford University, 318 Campus Drive, Room S321, James H. Clark Center, MC 5454, Stanford, California, 94305-5454 USA
Correspondence to: S.L. Delp; e-mail: [email protected]Search for more papers by this authorABSTRACT
Introduction
Second-harmonic generation microendoscopy is a minimally invasive technique to image sarcomeres and measure their lengths in humans, but motion artifact and low signal have limited the use of this novel technique.
Methods
We discovered that an excitation wavelength of 960 nm maximized image signal; this enabled an image acquisition rate of 3 frames/s, which decreased motion artifact. We then used microendoscopy to measure sarcomere lengths in the human extensor carpi radialis brevis with the wrist at 45° extension and 45° flexion in 7 subjects. We also measured the variability in sarcomere lengths within single fibers.
Results
Average sarcomere lengths in 45° extension were 2.93±0.29 μm (±SD) and increased to 3.58±0.19 μm in 45° flexion. Within single fibers the standard deviation of sarcomere lengths in series was 0.20 μm.
Conclusions
Microendoscopy can be used to measure sarcomere lengths at different body postures. Lengths of sarcomeres in series within a fiber vary substantially. Muscle Nerve, 48: 286–292, 2013
Supporting Information
Additional Supporting Information may be found in the online version of this article.
| Filename | Description |
|---|---|
| mus23760-sup-0001-suppfig1.tif433.4 KB | SUPPLEMENTARY FIGURE S1. Normalized signal intensity in images of fresh muscle samples over a range of near-infrared excitation wavelengths (880–1,060 nm). An excitation wavelength of 960 nm produced the highest signal. Colors indicate the emission filters used (center wavelength, nm/full width at half maximum, nm). |
| mus23760-sup-0002-suppfig2.tif1.2 MB | SUPPLEMENTARY FIGURE S2. Subjects were seated with the left arm in a custom brace. Microendoscopy images in the extensor carpi radialis brevis (ECRB) were collected with the wrist in extension and flexion, while other joints remained fixed. The elbow was flexed to approximately 135°. The forearm was pronated such that the wrist flexion axis was horizontal. Radial/ulnar deviation was neutral. The fingers were extended. Subjects minimized motion relative to the microendoscope by keeping a spot from a laser pointer attached to the left shoulder within a small target approximately one meter away. |
| mus23760-sup-0003-suppfig3.tif79 KB | SUPPLEMENTARY FIGURE S3. Ultrasound image showing location of endoscope insertion into the extensor carpi radialis brevis (ECRB). The microendoscope was positioned at a repeatable depth and proximal–distal location. The position was selected to image sarcomeres within fibers (red line) that were at low angles to the microendoscope bottom face. Tip depth was 1 cm below the skin surface. In 3 subjects, fascicle angles near the endoscope tip were measured relative to the horizontal in ultrasound images. Angles were 5.8±3.3°. Scale bar=5 mm. |
| mus23760-sup-0004-suppfig4.tif1.5 MB | SUPPLEMENTARY FIGURE S4. The microendoscope was inserted into the subject's muscle with a custom needle delivery system. (a) A stainless steel central stylet with guide tube was inserted into the muscle using the injector (injector not shown). (b) The central stylet was removed, and the guide tube was left in the muscle. (c) The tube was held in place with a custom clamp, and the microendoscope was placed in the guide tube. |
| mus23760-sup-0005-suppfig5.tif1.4 MB | SUPPLEMENTARY FIGURE S5. Microendoscopy images of sarcomeres in the extensor carpi radialis brevis (ECRB) from 6 additional subjects with the wrist extended (left column) and flexed (right column). Images in the same row are from the same subject. Bright regions in the image (pseudocolored blue) are myosin-containing A-bands. Scale bar=10 μm. |
Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
References
- 1Gordon AM, Huxley AF, Julian FJ. The variation in isometric tension with sarcomere length in vertebrate muscle fibres. J Physiol 1966; 184: 170–192.
- 2Lieber RL, Loren GJ, Friden J. In vivo measurement of human wrist extensor muscle sarcomere length changes. J Neurophysiol 1994; 71: 874–881.
- 3Murray WM, Hentz VR, Friden J, Lieber RL. Variability in surgical technique for brachioradialis tendon transfer. Evidence and implications. J Bone Joint Surg Am 2006; 88: 2009–2016.
- 4Ponten E, Gantelius S, Lieber RL. Intraoperative muscle measurements reveal a relationship between contracture formation and muscle remodeling. Muscle Nerve 2007; 36: 47–54.
- 5Smith LR, Lee KS, Ward SR, Chambers HG, Lieber RL. Hamstring contractures in children with spastic cerebral palsy result from a stiffer extracellular matrix and increased in vivo sarcomere length. J Physiol 2011; 589: 2625–2639.
- 6Llewellyn ME, Barretto RP, Delp SL, Schnitzer MJ. Minimally invasive high-speed imaging of sarcomere contractile dynamics in mice and humans. Nature 2008; 454: 784–788.
- 7Julian FJ, Moss RL. Sarcomere length-tension relations of frog skinned muscle fibres at lengths above the optimum. J Physiol 1980; 304: 529–539.
- 8Gollapudi SK, Lin DC. Experimental determination of sarcomere force-length relationship in type-I human skeletal muscle fibers. J Biomech 2009; 42: 2011–2016.
- 9Edman KA, Caputo C, Lou F. Depression of tetanic force induced by loaded shortening of frog muscle fibres. J Physiol 1993; 466: 535–552.
- 10Julian FJ, Morgan DL. Intersarcomere dynamics during fixed-end tetanic contractions of frog muscle fibres. J Physiol 1979; 293: 365–378.
- 11Huxley AF, Simmons RM. A quick phase in the series-elastic component of striated muscle, demonstrated in isolated fibres from the frog. J Physiol 1970; 208: 52P–53P.
- 12Shimamoto Y, Suzuki M, Mikhailenko SV, Yasuda K, Ishiwata S. Inter-sarcomere coordination in muscle revealed through individual sarcomere response to quick stretch. Proc Natl Acad Sci USA 2009; 106: 11954–11959.
- 13Okamura N, Ishiwata S. Spontaneous oscillatory contraction of sarcomeres in skeletal myofibrils. J Muscle Res Cell Motil 1988; 9: 111–119.
- 14Rassier DE, Herzog W, Pollack GH. Dynamics of individual sarcomeres during and after stretch in activated single myofibrils. Proc Biol Sci 2003; 270: 1735–1740.
- 15Telley IA, Stehle R, Ranatunga KW, Pfitzer G, Stussi E, Denoth J. Dynamic behaviour of half-sarcomeres during and after stretch in activated rabbit psoas myofibrils: Sarcomere asymmetry but no ‘sarcomere popping’. J Physiol 2006; 573: 173–185.
- 16Telley IA, Denoth J, Stussi E, Pfitzer G, Stehle R. Half-sarcomere dynamics in myofibrils during activation and relaxation studied by tracking fluorescent markers. Biophys J 2006; 90: 514–530.
- 17Friden J, Lieber RL. Physiologic consequences of surgical lengthening of extensor carpi radialis brevis muscle-tendon junction for tennis elbow. J Hand Surg [Am] 1994; 19: 269–274.
- 18Lieber RL, Ljung BO, Friden J. Sarcomere length in wrist extensor muscles. Changes may provide insights into the etiology of chronic lateral epicondylitis. Acta Orthop Scand 1997; 68: 249–254.
- 19Plotnikov SV, Millard AC, Campagnola PJ, Mohler WA. Characterization of the myosin-based source for second-harmonic generation from muscle sarcomeres. Biophys J 2006; 90: 693–703.
- 20Ljung BO, Friden J, Lieber RL. Sarcomere length varies with wrist ulnar deviation but not forearm pronation in the extensor carpi radialis brevis muscle. J Biomech 1999; 32: 199–202.
- 21Friedrich O, Both M, Weber C, Schurmann S, Teichmann MD, von Wegner F, et al. Microarchitecture is severely compromised but motor protein function is preserved in dystrophic mdx skeletal muscle. Biophys J 2010; 98: 606–616.
- 22Ralston E, Swaim B, Czapiga M, Hwu WL, Chien YH, Pittis MG, et al. Detection and imaging of non-contractile inclusions and sarcomeric anomalies in skeletal muscle by second-harmonic generation combined with two-photon excited fluorescence. J Struct Biol 2008; 162: 500–508.
- 23Infantolino BW, Ellis MJ, Challis JH. Individual sarcomere lengths in whole muscle fibers and optimal fiber length computation. Anat Rec (Hoboken) 2010; 293: 1913–1919.
- 24Plotnikov SV, Kenny AM, Walsh SJ, Zubrowski B, Joseph C, Scranton VL, et al. Measurement of muscle disease by quantitative second-harmonic generation imaging. J Biomed Opt 2008; 13: 044018.
- 25Loren GJ, Lieber RL. Tendon biomechanical properties enhance human wrist muscle specialization. J Biomech 1995; 28: 791–799.
- 26Holzbaur KR, Murray WM, Delp SL. A model of the upper extremity for simulating musculoskeletal surgery and analyzing neuromuscular control. Ann Biomed Eng 2005; 33: 829–840.
- 27Arnold EM, Delp SL. Fibre operating lengths of human lower limb muscles during walking. Philos Trans R Soc Lond B Biol Sci 2011; 366: 1530–1539.
- 28Delp SL, Arnold AS, Speers RA, Moore CA. Hamstrings and psoas lengths during normal and crouch gait: implications for muscle-tendon surgery. J Orthop Res 1996; 14: 144–151.
- 29Jung JC, Mehta AD, Aksay E, Stepnoski R, Schnitzer MJ. In vivo mammalian brain imaging using one- and two-photon fluorescence microendoscopy. J Neurophysiol 2004; 92: 3121–3133.
- 30Jung JC, Schnitzer MJ. Multiphoton endoscopy. Opt Lett 2003; 28: 902–904.
Citing Literature
