The Variable Insertional Anatomy of the Abductor Pollicis Longus: Functional Relevance and Relationship to Adjacent Thumb Extensors

Hand ◽  
2021 ◽  
pp. 155894472199973
Author(s):  
Shruthi Deivasigamani ◽  
Ali Azad ◽  
S. Steven Yang

Background The abductor pollicis longus (APL) is classically described as inserting on the base of the first metacarpal. This study analyzed APL insertional anatomy and quantified the size of various elements of the extensor side of the thumb to determine associations with size and function. Methods Twenty-four formalin-preserved upper limbs were dissected. The insertional anatomy of the APL, extensor pollicis brevis, and extensor pollicis longus were characterized, and the capacity of APL tendon slips to perform palmar abduction of the first digit was quantified based on slip size and insertion. Results The mean number of APL tendon slips observed was 2.3. Abductor pollicis longus insertion sites included the base of the first metacarpal, trapezium, abductor pollicis brevis, and opponens pollicis. Only 4 specimens had a solitary metacarpal slip, while 83% of specimens had insertions onto at least 1 thenar muscle. A total of 62.5% of APL tendons exhibited some form of branching that we categorized into “Y” and “Z” patterns. In assessing palmar abduction capacity, we found that APL tendon slips inserting into the base of the first metacarpal were larger in cross-sectional area than nonmetacarpal slips and reproduced complete palmar abduction of the digit in the absence of nonmetacarpal slips. The abduction capacity of APL tendon slips was not correlated to the cross-sectional area. Conclusions There is significant variability in APL tendon slips, branching patterns, and insertional anatomy. These findings provide further understanding of the function of the APL and its surgical implications.

2016 ◽  
Vol 52 (1) ◽  
pp. 12-23 ◽  
Author(s):  
Ran S Sopher ◽  
Andrew A Amis ◽  
D Ceri Davies ◽  
Jonathan RT Jeffers

Data about a muscle’s fibre pennation angle and physiological cross-sectional area are used in musculoskeletal modelling to estimate muscle forces, which are used to calculate joint contact forces. For the leg, muscle architecture data are derived from studies that measured pennation angle at the muscle surface, but not deep within it. Musculoskeletal models developed to estimate joint contact loads have usually been based on the mean values of pennation angle and physiological cross-sectional area. Therefore, the first aim of this study was to investigate differences between superficial and deep pennation angles within each muscle acting over the ankle and predict how differences may influence muscle forces calculated in musculoskeletal modelling. The second aim was to investigate how inter-subject variability in physiological cross-sectional area and pennation angle affects calculated ankle contact forces. Eight cadaveric legs were dissected to excise the muscles acting over the ankle. The mean surface and deep pennation angles, fibre length and physiological cross-sectional area were measured. Cluster analysis was applied to group the muscles according to their architectural characteristics. A previously validated OpenSim model was used to estimate ankle muscle forces and contact loads using architecture data from all eight limbs. The mean surface pennation angle for soleus was significantly greater (54%) than the mean deep pennation angle. Cluster analysis revealed three groups of muscles with similar architecture and function: deep plantarflexors and peroneals, superficial plantarflexors and dorsiflexors. Peak ankle contact force was predicted to occur before toe-off, with magnitude greater than five times bodyweight. Inter-specimen variability in contact force was smallest at peak force. These findings will help improve the development of experimental and computational musculoskeletal models by providing data to estimate force based on both surface and deep pennation angles. Inter-subject variability in muscle architecture affected ankle muscle and contact loads only slightly. The link between muscle architecture and function contributes to the understanding of the relationship between muscle structure and function.


2013 ◽  
Vol 115 (8) ◽  
pp. 1119-1125 ◽  
Author(s):  
Yuki Fujimoto ◽  
Jyongsu Huang ◽  
Toshiharu Fukunaga ◽  
Ryo Kato ◽  
Mari Higashino ◽  
...  

The acoustic reflection technique noninvasively measures airway cross-sectional area vs. distance functions and uses a wave tube with a constant cross-sectional area to separate incidental and reflected waves introduced into the mouth or nostril. The accuracy of estimated cross-sectional areas gets worse in the deeper distances due to the nature of marching algorithms, i.e., errors of the estimated areas in the closer distances accumulate to those in the further distances. Here we present a new technique of acoustic reflection from measuring transmitted acoustic waves in the airway with three microphones and without employing a wave tube. Using miniaturized microphones mounted on a catheter, we estimated reflection coefficients among the microphones and separated incidental and reflected waves. A model study showed that the estimated cross-sectional area vs. distance function was coincident with the conventional two-microphone method, and it did not change with altered cross-sectional areas at the microphone position, although the estimated cross-sectional areas are relative values to that at the microphone position. The pharyngeal cross-sectional areas including retropalatal and retroglossal regions and the closing site during sleep was visualized in patients with obstructive sleep apnea. The method can be applicable to larger or smaller bronchi to evaluate the airspace and function in these localized airways.


2016 ◽  
Vol 54 (4) ◽  
pp. 342-347
Author(s):  
M.H.S. Moxness ◽  
V. Bugten ◽  
W.M. Thorstensen ◽  
S. Nordgard ◽  
G. Bruskeland

Background: The differences in nasal geometry and function between OSA patients and healthy individuals are not known. Our aim was to evaluate the differences in nasal geometry and function using acoustic rhinometry (AR) and peak nasal inspiratory flow (PNIF) between an OSA population and healthy controls. Methodology: The study was designed as a prospective case-control study. Ninety-three OSA patients and 92 controls were enrolled from 2010 to 2015. The minimal cross-sectional area (MCA) and the nasal cavity volume (NCV) in two parts of the nose (MCA0-3/NCV0-3 and MCA3-5.2/NCV3-5.2) and PNIF were measured at baseline and after decongestion. Results: The mean MCA0-3 in the OSA group was 0.49 cm2; compared to 0.55 cm2 in controls. The mean NCV0-3 correspondingly was 2.51 cm3 compared to 2.73 cm3 in controls. PNIF measured 105 litres/minute in the OSA group and 117 litres/minute in the controls. Conclusions: OSA patients have a lower minimum cross-sectional area, nasal cavity volume and peak inspiratory flow compared to controls. Our study supports the view that changes in the nasal cavity may contribute to development of OSA.


2011 ◽  
Vol 301 (5) ◽  
pp. R1358-R1366 ◽  
Author(s):  
Jarrod E. Church ◽  
Stefan M. Gehrig ◽  
Annabel Chee ◽  
Timur Naim ◽  
Jennifer Trieu ◽  
...  

Nitric oxide (NO) is an important signaling molecule produced in skeletal muscle primarily via the neuronal subtype of NO synthase (NOS1, or nNOS). While many studies have reported NO production to be important in muscle regeneration, none have examined the contribution of nNOS-derived NO to functional muscle regeneration (i.e., restoration of the muscle's ability to produce force) after acute myotoxic injury. In the present study, we tested the hypothesis that genetic deletion of nNOS would impair functional muscle regeneration after myotoxic injury in nNOS−/− mice. We found that nNOS−/− mice had lower body mass, lower muscle mass, and smaller myofiber cross-sectional area and that their tibialis anterior (TA) muscles produced lower absolute tetanic forces than those of wild-type littermate controls but that normalized or specific force was identical between the strains. In addition, muscles from nNOS−/− mice were more resistant to fatigue than those of wild-type littermates ( P < 0.05). To determine whether deletion of nNOS affected muscle regeneration, TA muscles from nNOS−/− mice and wild-type littermates were injected with the myotoxin notexin to cause complete fiber degeneration, and muscle structure and function were assessed at 7 and 10 days postinjury. Myofiber cross-sectional area was lower in regenerating nNOS−/− mice than wild-type controls at 7 and 10 days postinjury; however, contrary to our original hypothesis, no difference in force-producing capacity of the TA muscle was evident between the two groups at either time point. Our findings reveal that nNOS is not essential for functional muscle regeneration after acute myotoxic damage.


2020 ◽  
Author(s):  
Waruna Peiris ◽  
Flavia M Cicuttini ◽  
Maria Constantinou ◽  
Abbas Yaqobi ◽  
Sultana Monira Hussain ◽  
...  

Abstract Objective: To examine the associations between hip muscle cross-sectional area and hip pain and function in community-based individuals with mild-to-moderate hip osteoarthritis. Methods: This study included 27 participants with mild-to-moderate hip osteoarthritis. Cross-sectional area of hip muscles, including psoas major, rectus femoris, gluteus maximus, gluteus medius and minimus, adductor longus and magnus, obturator internus, and obturator externus, were measured from magnetic resonance images. Hip pain and function were evaluated using the Hip Disability and Osteoarthritis Outcome Score (HOOS). Results: After adjusting for age and gender, greater cross-sectional area of adductor longus and magnus was associated with a higher HOOS score in quality of life (regression coefficient 1.4, 95% confidence interval (CI) 0.2-2.7, p=0.02), activity of daily living (regression coefficient 1.3, 95% CI 0.1-2.6, p=0.04) and sport and recreation function (regression coefficient 1.6, 95% CI 0.1-3.0, p=0.04). Greater cross-sectional area of psoas major was associated with a higher quality of life score (regression coefficient 3.6, 95% CI -0.5 to 7.7, p=0.08). The cross-sectional area of hip muscles was not significantly associated with HOOS pain or symptom score. Conclusion: Greater cross-sectional area of hip adductors was associated with better function and quality of life in individuals with mild-to-moderate hip osteoarthritis. Greater cross-sectional area of hip flexors might be associated with better quality of life. These findings, while need to be confirmed in longitudinal studies, suggest that targeting the hip adductor and flexor muscles may improve function and quality of life in those with mild-to-moderate hip osteoarthritis.


1995 ◽  
Vol 79 (5) ◽  
pp. 1571-1577 ◽  
Author(s):  
B. J. Petrof ◽  
S. B. Gottfried ◽  
J. Eby ◽  
J. Lamanca ◽  
S. Levine

The present study tested the hypothesis that growth hormone (GH), an anabolic agent, could prevent the abnormalities of diaphragm structure and function associated with short-term administration of the corticosteroid triamcinolone (TR). During a 10-day period, male rats (n = 33) were assigned to control (CTL), TR (1 mg.kg-1.day-1 im), and TR-GH (2 mg.kg-1.day-1 im) groups. Diaphragm weight was significantly reduced in the TR and TR-GH animals compared with the CTL animals, but there was no difference in the diaphragm-to-body weight ratio. Fiber type (I, IIa, and IIx/b) proportions did not differ among the three groups. However, in TR rats there was a significant reduction in the contribution of type IIx/b fibers to total diaphragm cross-sectional area due to marked atrophy (approximately 42% decrease in mean fiber cross-sectional area). There was no significant reversal of TR-induced type IIx/b fiber atrophy by concomitant GH administration. TR and TR-GH groups both exhibited a left-ward shift of the force-frequency relationship and enhanced in vitro fatigue resistance, whereas maximal specific force was unaltered. We conclude that GH does not prevent corticosteroid-induced effects on the diaphragm under these conditions, possibly as a result of reduced nutritional intake associated with TR administration.


2021 ◽  
pp. 036354652110266
Author(s):  
Monika L. Bayer ◽  
Maren Hoegberget-Kalisz ◽  
Rene B. Svensson ◽  
Mikkel H. Hjortshoej ◽  
Jens L. Olesen ◽  
...  

Background: Muscle strain injury leads to a high risk of recurrent injury in sports and can cause long-term symptoms such as weakness and pain. Scar tissue formation after strain injuries has been described, yet what ultrastructural changes might occur in the chronic phase of this injury have not. It is also unknown if persistent symptoms and morphological abnormalities of the tissue can be mitigated by strength training. Purpose: To investigate if heavy resistance training improves symptoms and structural abnormalities after strain injuries. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 30 participants with long-term weakness and/or pain after a strain injury of the thigh or calf muscles were randomized to eccentric heavy resistance training of the injured region or control exercises of the back and abdominal muscle. Isokinetic (hamstring) or isometric (calf) muscle strength was determined, muscle cross-sectional area measured, and pain and function evaluated. Scar tissue ultrastructure was determined from biopsy specimens taken from the injured area before and after the training intervention. Results: Heavy resistance training over 3 months improved pain and function, normalized muscle strength deficits, and increased muscle cross-sectional area in the previously injured region. No systematic effect of training was found upon pathologic infiltration of fat and blood vessels into the previously injured area. Control exercises had no effect on strength, cross-sectional area, or scar tissue but a positive effect on patient-related outcome measures, such as pain and functional scores. Conclusion: Short-term strength training can improve sequelae symptoms and optimize muscle function even many years after a strain injury, but it does not seem to influence the overall structural abnormalities of the area with scar tissue. Registration: NCT02152098 (ClinicalTrials.gov identifier).


2007 ◽  
Vol 85 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Christopher H. Lusk ◽  
Mylthon Jiménez-Castillo ◽  
Nicolás Salazar-Ortega

The hydraulic efficiency conferred by vessels is regarded as one of the key innovations explaining the historical rise of the angiosperms at the expense of the gymnosperms. Few studies, however, have compared the structure and function of xylem and their relationships with foliage traits in evergreen representatives of both groups. We measured sapwood cross-sectional area, conduit diameters, hydraulic conductance, and leaf area of fine branches (2.5–7.5 mm diameter) of five conifers and eight evergreen angiosperm trees in evergreen temperate forests in south-central Chile. Conductance of both lineages was higher at Los Lleuques, a warm temperate site with strong Mediterranean influence, than in a cool temperate rain forest at Puyehue. At a common sapwood cross-sectional area, angiosperm branches at both sites had greater hydraulic conductance (G) than conifers, but similar leaf areas. Branch conductance normalized by subtended leaf area (GL) at both sites was, therefore, higher in angiosperms than in conifers. Hydraulically weighted mean conduit diameters were much larger in angiosperms than in conifers, although this difference was less marked at Puyehue, the cooler of the two sites. Conduits of the vesselless rain forest angiosperm Drimys winteri J.R. & G. Forst were wider than those of coniferous associates, although narrower than angiosperm vessels. However, GL of D. winteri was within the range of values measured for vesselbearing angiosperms at the same site. The observed differences in xylem structure and function correlate with evidence that evergreen angiosperms have higher average stomatal conductance and photosynthetic capacity than their coniferous associates in southern temperate forests. Comparisons of conifers and angiosperm branches thus suggest that the superior capacity of angiosperm conduits is attributable to the development of higher gas-exchange rates per unit leaf area, rather than to a more extensive leaf area. Results also suggest that the tracheary elements of some vesselless angiosperms differ in width and hydraulic efficiency from conifer tracheids.


2014 ◽  
Vol 26 (1) ◽  
pp. 172
Author(s):  
R. Miura ◽  
H. Takahashi ◽  
S. Haneda ◽  
M. Matsui

The characteristics of the corpus luteum (CL) are greatly affected by the characteristics of the preceeding preovulatory follicle, such as follicle size and function. A previous study reported that the concentration of oestradiol in follicular fluid and production of androstenedione and progesterone (P4) by cultured theca cells are higher in the first follicular wave dominant follicle than in the second follicular wave dominant follicle. In addition, blood flow in the wall of the preovulatory follicle is higher in the first follicular wave than in the second follicular wave. These results suggest that the characteristics of the dominant follicle in the first and the second follicular wave may be different. The objective of this study was to compare CL characteristics, such as diameter, cross-sectional area, blood flow area, and plasma P4 concentration after ovulation of the dominant follicle between the first and the second follicular waves. Preovulatory follicles and CL formed after ovulation of the first follicular wave (W1; n = 5) and second follicular wave (W2; n = 6) were examined in non-lactating Holstein cows. In W1, PGF2α and GnRH were administrated on D7 and D9 of the oestrus cycle (D0 = oestrus), respectively, to induce follicular maturation. In W2, GnRH was administrated on D6 to induce a new follicular wave; subsequently, PGF2α and GnRH were administrated on D14 and D16, respectively. Diameter and percentage of follicular circumference with blood flow of preovulatory follicle on D10 in W1 and D17 in W2 were measured by transrectal colour Doppler ultrasonography. Diameter, cross-sectional area, and blood flow area of CL formed after ovulation in W1 (W1CL) and W2 (W2CL) were also examined on Day 3, 6, and 9 after ovulation (Day 1 = ovulation day). Blood samples were collected from Day 1 to 9 for P4 measurement. Quantitative end-points for diameter and percentage of follicular circumference with blood flow of the preovulatory follicle were analysed between the groups by using the unpaired Student's t-test. Diameter, cross-sectional area, blood flow area of CL, and plasma P4 concentration were analysed by repeated-measures ANOVA followed by Scheffe's F-test as a multiple comparison test. Larger diameter and higher percentage of follicular circumference with blood flow of the preovulatory follicle were observed in W1 compared with those in W2 (P < 0.01). Diameter of CL was larger in W1CL than in W2CL regardless of day (P < 0.001). Cross-sectional area of CL was larger in W1CL than in W2CL on Day 6 and 9 but not on Day 3. Blood flow area of CL was larger in W1CL than in W2CL on Day 3 and 6 but not in Day 9. Plasma P4 concentrations were higher in W1CL than in W2CL on Day5 and 7 (P < 0.05). In conclusion, larger size and higher percentage of follicular circumference with blood flow of preovulatory follicle in W1 lead to a larger size and a blood flow area of CL as well as higher plasma P4 concentration. These results suggest that preovulatory blood flow status affects the morphology and function of CL.


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