Muscle-fiber pennation angles are greater in hypertrophied than in normal muscles
Abstract
Muscle-fiber pennation angles were measured in vivo with the use of ultrasonography to investigate the relationship between fiber pennation and muscle size for 32 male subjects (from untrained subjects to highly trained bodybuilders). From the image of a B-mode ultrasonogram, fiber pennation angles and thickness of triceps brachii were determined, the former as angles between echoes from the interspaces of fascicles and from the aponeurosis of long and medial heads of triceps and the latter as the distance between the fat-muscle and muscle-bone interfaces. The pennation angles were in the range of 15 and 53 degrees for the long head and 9 to 26 degrees for the medial head, which were similar to or greater than the published and the present data on human cadavers. Significant differences were observed between normal subjects and bodybuilders in muscle thickness and pennation angles (P < 0.01), and there were significant correlations between muscle thickness and pennation angles for both long (r = 0.884) and medial (r = 0.833) heads of triceps, suggesting that muscle hypertrophy involves an increase in fiber pennation angles.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
A greater QΘP facilitates the attachment of more contractile material and application of more force to the tendon/aponeurosis, independently from any increase in muscle ACSA or volume.
“A greater QΘP facilitates the attachment of more contractile material, and thus the application of more force, to the tendon/aponeurosis [i.e., as reflected by PCSA (40, 45, 47, 61)], independently from any increase in muscle ACSA or volume”
From What makes long-term resistance-trained individuals so strong? A comparison of skeletal muscle morphology, architecture, and joint mechanics (2020) · cites this paper as [47]
Resistance-trained individuals/bodybuilders have previously been found to have much higher ΘP in the triceps brachii, mid-point vastus lateralis, and medial gastrocnemius.
“Resistance-trained individuals/bodybuilders have previously been found to have much higher ΘP in both the triceps brachii [33° vs. 15°; +120% (47)], mid-point vastus lateralis (20.4° vs. 15.5°; +31% (39)], and medial gastrocnemius [24.6° vs. 18.4°; +34% (39)]”
From What makes long-term resistance-trained individuals so strong? A comparison of skeletal muscle morphology, architecture, and joint mechanics (2020) · cites this paper as [47]
Cites
Muscle Architecture of the Human Lower Limb
Wickiewicz, T. L., Roy, R. R., Powell, P. L., & Edgerton, V. R. (1983) · Clinical Orthopaedics and Related Research · doi:10.1097/00003086-198310000-00042 · Cited by 932 · see citing works
Narici, M. V., Roi, G. S., Landoni, L., Minetti, A. E., & Cerretelli, P. (1989) · European Journal of Applied Physiology · doi:10.1007/bf02388334 · Cited by 745 · see citing works
Muscles across the elbow joint: A biomechanical analysis
An, K. N., Hui, F. C., Morrey, B. F., Linscheid, R. L., & Chao, E. Y. S. (1981) · Journal of Biomechanics · doi:10.1016/0021-9290(81)90048-8 · Cited by 623 · see citing works
Ikai, M., & Fukunaga, T. (1968) · European Journal of Applied Physiology · doi:10.1007/bf00696087 · Cited by 565 · see citing works
Self-citationMuscle Strengths and Musculoskeletal Geometry of the Upper Limb
Amis, A. A., Dowson, D., & Wright, V. A. (1979) · Engineering in Medicine · doi:10.1243/emed_jour_1979_008_010_02 · Cited by 187 · see citing works
Maughan, R., Watson, J. S., & Weir, J. P. (1984) · British Journal of Sports Medicine · doi:10.1136/bjsm.18.3.149 · Cited by 128 · see citing works
The range of sarcomere lengths in the muscles of the human lower limb.
Cutts, A. (1988) · PubMed · Cited by 125 · see citing works
Davies, J., Parker, D. F., Rutherford, O. M., & Jones, D. A. (1988) · European Journal of Applied Physiology and Occupational Physiology · doi:10.1007/bf01075986 · Cited by 110 · see citing works
Do muscle fibre size and fibre angulation correlate in pennated human muscles?
Henriksson-Larsén, K., Wretling, M.-L., Lorentzon, R., & �berg, L. (1992) · European Journal of Applied Physiology · doi:10.1007/bf00376443 · Cited by 90 · see citing works
Measurement of anterior tibial muscle size using real-time ultrasound imaging
Martinson, H., & Stokes, M. J. (1991) · European Journal of Applied Physiology · doi:10.1007/bf00233856 · Cited by 86 · see citing works
Estimation of number of fibers in guinea pig skeletal muscles.
Maxwell, L., Faulkner, J. A., & Hyatt, G. J. (1974) · Journal of Applied Physiology · doi:10.1152/jappl.1974.37.2.259 · Cited by 80 · see citing works
Huijing, P. A., Campagne, V. L., & Koper, J. F. (1989) · Cells Tissues Organs · doi:10.1159/000146721 · Cited by 45 · see citing works
Ultrasonic measurement of upper-arm skeletal muscle thickness.
Lw, W., & Fc, C. (1987) · PubMed · Cited by 10 · see citing works
Flagged first, then by citations
Cited by
Sorted by citations
Progression Models in Resistance Training for Healthy Adults
(2009) · Medicine & Science in Sports & Exercise · doi:10.1249/mss.0b013e3181915670 · Cited by 4,332 · see citing works
Progression Models in Resistance Training for Healthy Adults
(2002) · Medicine and Science in Sports and Exercise · doi:10.1097/00005768-200202000-00027 · Cited by 2,979 · see citing works
Folland, J. P., & Williams, A. G. (2007) · Sports Medicine · doi:10.2165/00007256-200737020-00004 · Cited by 1,347 · see citing works
The importance of muscular strength: Training considerations
Suchomel, T. J., Nimphius, S., Bellon, C. R., & Stone, M. H. (2018) · Sports Medicine · doi:10.1007/s40279-018-0862-z · Cited by 940 · see citing works
Sarcopenia: characteristics, mechanisms and functional significance
Narici, M. V., & Maffulli, N. (2010) · British Medical Bulletin · doi:10.1093/bmb/ldq008 · Cited by 827 · see citing works
Developing Maximal Neuromuscular Power: Part 1 – Biological Basis of Maximal Power Production
Cormie, P., McGuigan, M. R., & Newton, R. U. (2011) · Sports Medicine · doi:10.2165/11537690-000000000-00000 · Cited by 774 · see citing works
Effects of Resistance Training on Older Adults
Hunter, G. R., McCarthy, J. P., & Bamman, M. M. (2004) · Sports Medicine · doi:10.2165/00007256-200434050-00005 · Cited by 764 · see citing works
Aagaard, P., Andersen, J. L., Dyhre‐Poulsen, P., Leffers, A., Wagner, A., Magnusson, S. P., Halkjær‐Kristensen, J., & Simonsen, E. B. (2001) · The Journal of Physiology · doi:10.1111/j.1469-7793.2001.t01-1-00613.x · Cited by 733 · see citing works
Neuromuscular adaptations during concurrent strength and endurance training versus strength training
Häkkinen, K., Alen, M., Kraemer, W. J., Gorostiaga, E., Izquierdo, M., Rusko, H., Mikkola, J., Häkkinen, A., Valkeinen, H., Kaarakainen, E., et al. (2003) · European Journal of Applied Physiology · doi:10.1007/s00421-002-0751-9 · Cited by 527 · see citing works
Abe, T., DeHoyos, D. V., Pollock, M. L., & Garzarella, L. (2000) · European Journal of Applied Physiology and Occupational Physiology · doi:10.1007/s004210050027 · Cited by 523 · see citing works
Self-citationFranchi, M. V., Atherton, P. J., Reeves, N. D., Flück, M., Williams, J., Mitchell, W. K., Selby, A., Beltran Valls, R. M., & Narici, M. V. (2014) · Acta Physiologica · doi:10.1111/apha.12225 · Cited by 389 · see citing works
Muscle quality. II. Effects of strength training in 65- to 75-yr-old men and women
Tracy, B. L., Ivey, F. M., Hurlbut, D., Martel, G. F., Lemmer, J. T., Siegel, E. L., Metter, E. J., Fozard, J. L., Fleg, J. L., & Hurley, B. F. (1999) · Journal of Applied Physiology · doi:10.1152/jappl.1999.86.1.195 · Cited by 371 · see citing works
Differential adaptations to eccentric <i>versus</i> conventional resistance training in older humans
Reeves, N. D., Maganaris, C. N., Longo, S., & Narici, M. V. (2009) · Experimental Physiology · doi:10.1113/expphysiol.2009.046599 · Cited by 274 · see citing works
Fragala, M. S., Kenny, A. M., & Kuchel, G. A. (2015) · Sports Medicine · doi:10.1007/s40279-015-0305-z · Cited by 246 · see citing works
Exercise attenuates the weight-loss-induced reduction in muscle mass in frail obese older adults
FRIMEL, T. N., SINACORE, D. R., & VILLAREAL, D. T. (2008) · Medicine & Science in Sports & Exercise · doi:10.1249/mss.0b013e31816a85ce · Cited by 230 · see citing works
Andersen, L. L., Andersen, J. L., Magnusson, S. P., Suetta, C., Madsen, J. L., Christensen, L. R., & Aagaard, P. (2005) · Journal of Applied Physiology · doi:10.1152/japplphysiol.00091.2005 · Cited by 193 · see citing works
Sex hormones and skeletal muscle weakness
Sipilä, S., Narici, M., Kjaer, M., Pöllänen, E., Atkinson, R. A., Hansen, M., & Kovanen, V. (2013) · Biogerontology · doi:10.1007/s10522-013-9425-8 · Cited by 106 · see citing works
The impact of obesity on skeletal muscle architecture in untrained young vs. old women
Tomlinson, D. J., Erskine, R. M., Winwood, K., Morse, C. I., & Onambélé, G. L. (2014) · Journal of Anatomy · doi:10.1111/joa.12248 · Cited by 87 · see citing works
Maden-Wilkinson, T. M., Balshaw, T. G., Massey, G. J., & Folland, J. P. (2020) · Journal of Applied Physiology · doi:10.1152/japplphysiol.00224.2019 · Cited by 81 · see citing works
Yagiz, G., Akaras, E., Kubis, H.-P., & Owen, J. A. (2022) · Applied Sciences · doi:10.3390/app12031593 · Cited by 72 · see citing works
Training Strategies to Improve Muscle Power: Is Olympic-style Weightlifting Relevant?
HELLAND, C., HOLE, E., IVERSEN, E., OLSSON, M. C., SEYNNES, O., SOLBERG, P. A., & PAULSEN, G. (2017) · Medicine & Science in Sports & Exercise · doi:10.1249/mss.0000000000001145 · Cited by 50 · see citing works
Fukutani, A., & Kurihara, T. (2015) · SpringerPlus · doi:10.1186/s40064-015-1133-1 · Cited by 44 · see citing works
Franchi, M. V., Atherton, P. J., Maganaris, C. N., & Narici, M. V. (2016) · SpringerPlus · doi:10.1186/s40064-015-1548-8 · Cited by 41 · see citing works
- Authors
- Kawakami, Y., Abe, T., & Fukunaga, T.
- Affiliations
- The University of Tokyo (JP)
- Venue
- Journal of Applied Physiology
- Publisher
- American Physiological Society
- Published
- 1993-06-01
- Volume
- 74
- Issue
- 6
- Pages
- 2740-2744
- ISSN
- 0161-7567 (ISSN-L)
- 8750-7587
- 1522-1601
- OpenAlex
- W1873619168
- Cited by
- 518
- References
- 13
- Citations by year
- 2026: 14 · 2025: 11 · 2024: 11 · 2023: 15 · 2022: 27 · 2021: 25 · 2020: 14 · 2019: 19 · 2018: 17 · 2017: 21 · 2016: 24 · 2015: 28 · 2014: 39 · 2013: 28 · 2012: 17
- FWCI
- 1.16
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Journal of Applied Physiology (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Muscle Physiology and Disorders
- Health Sciences › Medicine › Orthopedics and Sports Medicine › Sports Performance and Training
- Physical Sciences › Engineering › Biomedical Engineering › Muscle activation and electromyography studies
- Keywords
- muscle hypertrophy, triceps brachii, muscle thickness, bodybuilders, muscle size, aponeurosis, muscle architecture
- MeSH terms
- Adult, Aged, Aged, 80 and over, Female, Humans, Hypertrophy, Male, Muscles, Physical Education and Training, Ultrasonography
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
