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1.
J Sport Rehabil ; 30(5): 804-811, 2021 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-33596548

RESUMEN

CONTEXT: Localized and widespread hyperalgesia has been observed in patients with patellofemoral pain. Diacutaneous fibrolysis (DF) has shown to be effective in reducing pain in several musculoskeletal conditions including patellofemoral pain syndrome, but no studies have evaluated the effects of this technique in reducing localized and widespread hyperalgesia. OBJECTIVE: To assess the effect of DF on the pressure pain threshold and muscle length tests in patients with patellofemoral pain syndrome. DESIGN: A single-group, pretest-posttest clinical trial. SETTING: University of Zaragoza. PARTICIPANTS: Forty-six subjects with patellofemoral pain (20 males and 26 females: age 27.8 [6.9] y). INTERVENTION: Three sessions of DF. MAIN OUTCOME MEASURES: Pressure pain threshold using a handheld pressure algometer (4 sites around the knee, on tibialis anterior muscle, and one remote site on the upper contralateral limb); muscle length test of the iliotibial band, rectus femoris, and hamstring muscles; and patient-perceived treatment effect score. RESULTS: The application of 3 sessions of DF significantly increased the pressure pain threshold in all sites at posttreatment evaluation (P < .001) and at a 1-week follow-up (P < .001). A significant increase in muscle length was also observed at the posttreatment evaluation (P < .001) and 1-week follow-up (P < .001). Ninety-seven percent of the patients reported subjective improvement at posttreatment and at 1-week follow-up. CONCLUSION: This study found that local and widespread hyperalgesia was significantly reduced after 3 sessions of diacutaneous fibrolysis and at the 1-week follow-up. A significant improvement on muscle length tests was also observed, with high clinical satisfaction among patients.


Asunto(s)
Hiperalgesia/terapia , Manipulaciones Musculoesqueléticas/métodos , Umbral del Dolor/fisiología , Síndrome de Dolor Patelofemoral/terapia , Adulto , Femenino , Músculos Isquiosurales/anatomía & histología , Músculos Isquiosurales/fisiopatología , Humanos , Hiperalgesia/fisiopatología , Rodilla/fisiopatología , Masculino , Músculo Esquelético/anatomía & histología , Músculo Esquelético/fisiopatología , Tamaño de los Órganos , Síndrome de Dolor Patelofemoral/fisiopatología , Posicionamiento del Paciente/métodos , Presión , Músculo Cuádriceps/anatomía & histología , Músculo Cuádriceps/fisiopatología
2.
Muscle Nerve ; 57(1): E1-E7, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28632896

RESUMEN

INTRODUCTION: We studied the ability of clinicians to identify quadriceps motor points using a transcutaneous electrical stimulation unit (TENS). METHODS: Twenty-two certified athletic trainers and 1 expert-rater identified the 7 motor points of the quadriceps at 2 time-points separated by 1 week. The difference was calculated between where each participant and the expert-rater identified each motor point using an x-y coordinate system. Bland-Altman plots were used to compare differences between 2 testing sessions. RESULTS: No differences were observed between participants and the expert-rater for motor point location. The smallest variability in the limits of agreements were observed in the distal vastus medialis oblique (-1.89 to 1.86 cm) and proximal vastus lateralis (-1.61 to 2.35 cm). DISCUSSION: Our results suggest the utilization of a TENS unit may be 1 way to identify quadriceps motor points to improve electrical stimulation applications. The smallest limits of agreement were over the most common quadriceps electrical stimulation electrode positions. Muscle Nerve 57: E1-E7, 2018.


Asunto(s)
Músculo Cuádriceps/anatomía & histología , Adulto , Estimulación Eléctrica , Electromiografía , Femenino , Humanos , Masculino , Variaciones Dependientes del Observador , Músculo Cuádriceps/inervación , Reproducibilidad de los Resultados , Grasa Subcutánea/anatomía & histología , Estimulación Eléctrica Transcutánea del Nervio , Adulto Joven
3.
J Int Soc Sports Nutr ; 13: 25, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27293386

RESUMEN

BACKGROUND: Increased ATP levels may enhance training-induced muscle accretion and fat loss, and caffeine is a known ergogenic aid. A novel supplement containing ancient peat and apple extracts has reported enhanced mitochondrial ATP production and it has been coupled with an extended-release caffeine. Therefore, the purpose of this investigation was to determine the effects of this supplement on body composition when used in conjunction with 12 weeks of resistance training. METHODS: Twenty-one resistance-trained subjects (27.2 ± 5.6y; 173.5 ± 5.7 cm; 82.8 ± 12.0 kg) completed this study. Subjects supplemented daily with either 1 serving of the supplement (TRT), which consisted of 150 mg ancient peat and apple extracts, 180 mg blend of caffeine anhydrous and pterostilbene-bound caffeine, and 38 mg B vitamins, or an equal-volume, visually-identical placebo (PLA) 45 min prior to training or at the same time of day on rest days. Supervised resistance training consisted of 8 weeks of daily undulating periodized training followed by a 2-week overreach and a 2-week taper phase. Body composition was assessed using DEXA and ultrasound at weeks 0, 4, 8, 10, and 12. Vital signs and blood markers were assessed at weeks 0, 8, and 12. RESULTS: Significant group x time (p < 0.05) interactions were present for cross-sectional area of the rectus femoris, which increased in TRT (+1.07 cm(2)) versus PLA (-0.08 cm(2)), as well as muscle thickness (TRT: +0.49 cm; PLA: +0.04 cm). A significant group x time (p < 0.05) interaction existed for creatinine (TRT: +0.00 mg/dL; PLA: +0.15 mg/dL) and estimated glomerular filtration rate (TRT: -0.70 mL/min/1.73; PLA: -14.6 mL/min/1.73), which remained within clinical ranges, but no other significant observations were observed. CONCLUSIONS: Supplementation with a combination of extended-release caffeine and ancient peat and apple extracts may enhance resistance training-induced skeletal muscle hypertrophy without adversely affecting blood chemistry.


Asunto(s)
Adenosina Trifosfato/biosíntesis , Composición Corporal/efectos de los fármacos , Cafeína/administración & dosificación , Entrenamiento de Fuerza , Adulto , Biomarcadores/sangre , Recuento de Células Sanguíneas , Creatinina/sangre , Suplementos Dietéticos , Tasa de Filtración Glomerular , Humanos , Lípidos/sangre , Masculino , Malus , Placebos , Extractos Vegetales/administración & dosificación , Músculo Cuádriceps/anatomía & histología , Suelo , Complejo Vitamínico B/administración & dosificación
4.
Med Sci Sports Exerc ; 47(12): 2621-7, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26110693

RESUMEN

PURPOSE: Low-load voluntary exercise can induce muscle hypertrophy and strength gain in working muscles when combined with blood flow restriction (BFR). However, it is unknown whether such hypertrophy and strength gain can be induced by involuntary muscle contractions triggered via low-intensity neuromuscular electrical stimulation (NMES) combined with BFR. The purpose of this article was to investigate whether low-intensity NMES combined with BFR (NMES-BFR) could elicit muscle hypertrophy and strength gain in the quadriceps. METHODS: Eight untrained young male participants (mean ± SE; age, 26.2 ± 0.7 yr; height, 1.74 ± 0.02 m; body weight, 71.4 ± 4.8 kg) were subjected to 23 min of unilateral low-intensity (5%-10% of maximal voluntary contraction) NMES twice per day (5 d·wk⁻¹) for 2 wk: one leg received NMES-BFR and the other leg received NMES alone. Quadriceps muscle thickness and isometric and isokinetic strength were measured before and every week throughout the training and detraining periods. RESULTS: In NMES-BFR legs, muscle thickness increased after 2 wk of training (+3.9%) and decreased after 2 wk of detraining (-3.0%). NMES-BFR training also increased maximal knee extension strength in isometric (+14.2%) and isokinetic (+7.0% at 90°·s⁻¹ and +8.3% at 180°·s⁻¹) voluntary contractions. In addition, maximal isometric strength decreased (-6.8%), whereas no large fall (-1.9% at 90°·s⁻¹ and -0.6% at 180°·s⁻¹) in isokinetic maximal strength was evident after 2 wk of detraining. In legs that received NMES alone, no prominent change was observed; there was a negligible effect on isometric strength. CONCLUSION: Low-intensity NMES-BFR induces muscle hypertrophy and strength gain in untrained young male participants.


Asunto(s)
Estimulación Eléctrica , Fuerza Muscular/fisiología , Educación y Entrenamiento Físico/métodos , Músculo Cuádriceps/anatomía & histología , Músculo Cuádriceps/fisiología , Adulto , Humanos , Contracción Isométrica , Masculino , Contracción Muscular , Músculo Cuádriceps/irrigación sanguínea , Flujo Sanguíneo Regional
5.
Plast Reconstr Surg ; 135(1): 185e-198e, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25539326

RESUMEN

BACKGROUND: The vastus lateralis muscle is a versatile donor site for pedicled and free flaps that, despite great potential, remains unpopular. Although the muscle is classically described as a single belly, evidence exists for a more complex morphology. The aim of this study was to investigate the segmental anatomy of the vastus lateralis muscle and the feasibility of selective flap harvest. METHODS: Ten cadaveric lower limbs were investigated. Muscular partitions were identified according to morphologic architecture, vascular supply, and nerve supply; guidelines for selective flap harvest were described. Twenty-three segmental vastus lateralis (n = 14) or chimeric anterolateral thigh-vastus lateralis flaps (n = 9) were raised based on neurovascular segmental supply, and used as noninnervated free flaps for reconstruction of moderate and large defects of the head and neck, trunk, or lower limbs. Intraoperative electrostimulation was used to confirm segmental innervation. Lower limb function was evaluated through the Lower Extremity Functional Scale. RESULTS: The authors clearly identified three anatomical partitions, which receive a constant segmental neurovascular supply, and two aponeuroses. The authors successfully applied the proposed guidelines for flap harvesting to all 23 patients. Intraoperative electrostimulation confirmed functional integrity of both the flap and the spared partitions. All muscle flaps survived. Donor-site morbidity was negligible, with comparable mean preoperative and postoperative Lower Extremity Functional Scale values (67.7 versus 67.4; p > 0.05). CONCLUSIONS: This study provides detailed knowledge on the morphologic and neurovascular anatomy of the vastus lateralis muscle, which supports the authors' guidelines for selective flap harvesting. The technique described is safe and minimizes surgical damage.


Asunto(s)
Colgajos Tisulares Libres , Tratamientos Conservadores del Órgano/métodos , Músculo Cuádriceps/anatomía & histología , Músculo Cuádriceps/cirugía , Recolección de Tejidos y Órganos/métodos , Anciano , Anciano de 80 o más Años , Cadáver , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Guías de Práctica Clínica como Asunto
6.
Scand J Med Sci Sports ; 24(5): 788-98, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23647357

RESUMEN

In a comparative study, we investigated the effects of maximal eccentric or concentric resistance training combined with whey protein or placebo on muscle and tendon hypertrophy. 22 subjects were allocated into either a high-leucine whey protein hydrolysate + carbohydrate group (WHD) or a carbohydrate group (PLA). Subjects completed 12 weeks maximal knee extensor training with one leg using eccentric contractions and the other using concentric contractions. Before and after training cross-sectional area (CSA) of m. quadriceps and patellar tendon CSA was quantified with magnetic resonance imaging and a isometric strength test was used to assess maximal voluntary contraction (MVC) and rate of force development (RFD). Quadriceps CSA increased by 7.3 ± 1.0% (P < 0.001) in WHD and 3.4 ± 0.8% (P < 0.01) in PLA, with a greater increase in WHD compared to PLA (P < 0.01). Proximal patellar tendon CSA increased by 14.9 ± 3.1% (P < 0.001) and 8.1 ± 3.2% (P = 0.054) for WHD and PLA, respectively, with a greater increase in WHD compared to PLA (P < 0.05), with no effect of contraction mode. MVC and RFD increased by 15.6 ± 3.5% (P < 0.001) and 12-63% (P < 0.05), respectively, with no group or contraction mode effects. In conclusion, high-leucine whey protein hydrolysate augments muscle and tendon hypertrophy following 12 weeks of resistance training - irrespective of contraction mode.


Asunto(s)
Proteínas de la Leche , Ligamento Rotuliano/anatomía & histología , Hidrolisados de Proteína , Músculo Cuádriceps/anatomía & histología , Entrenamiento de Fuerza/métodos , Carbohidratos de la Dieta , Suplementos Dietéticos , Método Doble Ciego , Electromiografía , Ejercicio Físico/fisiología , Humanos , Hipertrofia , Leucina/administración & dosificación , Imagen por Resonancia Magnética , Masculino , Contracción Muscular/fisiología , Fuerza Muscular , Músculo Cuádriceps/fisiología , Proteína de Suero de Leche , Adulto Joven
7.
J Strength Cond Res ; 27(11): 3091-100, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23442287

RESUMEN

The purpose of this study was to examine the effects of 2 different types of protein supplementation on thigh muscle cross-sectional area (CSA), blood markers, muscular strength, endurance, and body composition after 8 weeks of low- or moderate-volume resistance training in healthy, recreationally trained, college-aged men. One hundred and six men were randomized into 5 groups: low-volume resistance training with bioenhanced whey protein (BWPLV; n = 22), moderate-volume resistance training with BWP (BWPMV; n = 20), moderate-volume resistance training with standard whey protein (SWPMV; n = 22), moderate-volume resistance training with a placebo (PLA; n = 21), or moderate-volume resistance training with no supplementation (CON; n = 21). Except for CON, all groups consumed 1 shake before and after each exercise session and one each on the nontraining day. The BWPLV, BWPMV, and SWPMV groups received approximately 20 g of whey protein per shake, whereas the BWP groups received 5 g of additional polyethylene glycosylated (PEG) leucine. Resistance training sessions were performed 3 times per week for 8 weeks. There were no interactions (p > 0.05) for muscle strength and endurance variables, body composition, muscle CSA, and safety blood markers, but the main effects for training were observed (p ≤ 0.05). However, the Albumin:Globulin ratio for SWPMV was lower (p = 0.037) than BWPLV and BWPMV. Relative protein intake (PROREL) indicated a significant interaction (p < 0.001) with no differences across groups at pre; however, BWPLV, BWPMV, and SWPMV had a greater intake than did PLA or CON at post (p < 0.001). This study indicated that 8 weeks of resistance training improved muscle performance and size similarly among groups regardless of supplementation.


Asunto(s)
Proteínas en la Dieta/administración & dosificación , Suplementos Dietéticos , Músculo Cuádriceps/anatomía & histología , Músculo Cuádriceps/fisiología , Entrenamiento de Fuerza , Adolescente , Adulto , Proteínas en la Dieta/efectos adversos , Suplementos Dietéticos/efectos adversos , Método Doble Ciego , Humanos , Masculino , Fuerza Muscular , Resistencia Física , Entrenamiento de Fuerza/efectos adversos , Entrenamiento de Fuerza/métodos , Albúmina Sérica/metabolismo , Seroglobulinas/metabolismo , Adulto Joven
8.
Med Sci Sports Exerc ; 45(3): 542-52, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22968306

RESUMEN

INTRODUCTION: Resistance training has been well established as an effective treatment strategy to increase skeletal muscle mass and strength in the elderly. We assessed whether dietary protein supplementation can further augment the adaptive response to prolonged resistance-type exercise training in healthy elderly men and women. METHODS: Healthy elderly men (n = 31, 70 ± 1 yr) and women (n = 29, 70 ± 1 yr) were randomly assigned to a progressive, 24-wk resistance-type exercise training program with or without additional protein supplementation (15 g·d-1). Muscle hypertrophy was assessed on a whole-body Dual-energy X-ray absorptiometry (DXA), limb (computed tomography), and muscle fiber (biopsy) level. Strength was assessed regularly by 1-repetition maximum (RM) strength testing. Functional capacity was assessed with a sit-to-stand and handgrip test. RESULTS: One-RM strength increased by 45% ± 6% versus 40% ± 3% (women) and 41% ± 4% versus 44% ± 3% (men) in the placebo versus protein group, respectively (P < 0.001), with no differences between groups. Leg muscle mass (women, 4% ± 1% vs 3% ± 1%; men, 3% ± 1% vs 3% ± 1%) and quadriceps cross-sectional area (women, 9% ± 1% vs 9% ± 1%; men, 9% ± 1% vs 10% ± 1%) increased similarly in the placebo versus protein groups (P < 0.001). Type II muscle fiber size increased over time in both placebo and protein groups (25% ± 13% vs 30% ± 9% and 23% ± 12% vs 22% ± 10% in the women and men, respectively). Sit-to-stand improved by 18% ± 2% and 19% ± 2% in women and men, respectively (P < 0.001). CONCLUSION: Prolonged resistance-type exercise training increases skeletal muscle mass and strength, augments functional capacity, improves glycemia and lipidemia, and reduces blood pressure in healthy elderly men and women. Additional protein supplementation (15 g·d-1) does not further increase muscle mass, strength, and/or functional capacity.


Asunto(s)
Adaptación Fisiológica , Proteínas en la Dieta/administración & dosificación , Suplementos Dietéticos , Músculo Cuádriceps/anatomía & histología , Músculo Cuádriceps/fisiología , Entrenamiento de Fuerza , Absorciometría de Fotón , Anciano , Análisis de Varianza , Composición Corporal , Colesterol/sangre , Creatinina/sangre , Femenino , Hemoglobina Glucada/metabolismo , Fuerza de la Mano , Humanos , Resistencia a la Insulina , Lipoproteínas LDL/sangre , Masculino , Fibras Musculares de Contracción Rápida/citología , Fuerza Muscular , Nitrógeno/orina , Músculo Cuádriceps/diagnóstico por imagen , Tomografía Computarizada por Rayos X
9.
Arch Phys Med Rehabil ; 94(5): 990-3, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23123504

RESUMEN

OBJECTIVE: To investigate the long-term effects of functional electrical stimulation (FES)-evoked cycle training cadence on leg muscle hypertrophy and electrically evoked strength. DESIGN: Open intervention study. SETTING: Laboratory setting. PARTICIPANTS: Untrained individuals with chronic spinal cord injury (N=8). INTERVENTIONS: Six weeks (3d/wk) of training on an isokinetic FES cycle ergometer. For each subject, 1 leg was randomly allocated to cycling at 10 revolutions per minute (rpm) (LOW) for 30min/d, and the other cycling at 50rpm (HIGH) for 30min/d. MAIN OUTCOME MEASURES: Pre- and posttraining measurements of lower limb circumference were performed at the distal and middle position of each thigh. Electrically evoked quadriceps muscle torque during an isometric contraction was also assessed. RESULTS: Six weeks of FES cycle training significantly increased thigh girth in both LOW and HIGH groups. At midthigh, girth increases induced by LOW (6.6%±1.2%) were significantly greater than those by HIGH (3.6%±0.8%). LOW also produced greater gains in electrically evoked isometric torque than HIGH after training. CONCLUSIONS: These results suggest that lower pedaling cadences evoke greater muscle hypertrophy and electrically stimulated muscle strength compared with higher cadences.


Asunto(s)
Terapia por Estimulación Eléctrica/métodos , Terapia por Ejercicio/métodos , Fuerza Muscular , Músculo Cuádriceps/anatomía & histología , Traumatismos de la Médula Espinal/rehabilitación , Adulto , Ciclismo/fisiología , Humanos , Persona de Mediana Edad , Tamaño de los Órganos , Proyectos Piloto , Músculo Cuádriceps/fisiopatología , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/fisiopatología , Torque
10.
Lasers Med Sci ; 26(3): 349-58, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21086010

RESUMEN

Recent studies have investigated whether low level laser therapy (LLLT) can optimize human muscle performance in physical exercise. This study tested the effect of LLLT on muscle performance in physical strength training in humans compared with strength training only. The study involved 36 men (20.8±2.2 years old), clinically healthy, with a beginner and/or moderate physical activity training pattern. The subjects were randomly distributed into three groups: TLG (training with LLLT), TG (training only) and CG (control). The training for TG and TLG subjects involved the leg-press exercise with a load equal to 80% of one repetition maximum (1RM) in the leg-press test over 12 consecutive weeks. The LLLT was applied to the quadriceps muscle of both lower limbs of the TLG subjects immediately after the end of each training session. Using an infrared laser device (808 nm) with six diodes of 60 mW each a total energy of 50.4 J of LLLT was administered over 140 s. Muscle strength was assessed using the 1RM leg-press test and the isokinetic dynamometer test. The muscle volume of the thigh of the dominant limb was assessed by thigh perimetry. The TLG subjects showed an increase of 55% in the 1RM leg-press test, which was significantly higher than the increases in the TG subjects (26%, P = 0.033) and in the CG subjects (0.27%, P < 0.001). The TLG was the only group to show an increase in muscle performance in the isokinetic dynamometry test compared with baseline. The increases in thigh perimeter in the TLG subjects and TG subjects were not significantly different (4.52% and 2.75%, respectively; P = 0.775). Strength training associated with LLLT can increase muscle performance compared with strength training only.


Asunto(s)
Terapia por Luz de Baja Intensidad , Entrenamiento de Fuerza/métodos , Adolescente , Humanos , Masculino , Modelos Biológicos , Fuerza Muscular/fisiología , Fuerza Muscular/efectos de la radiación , Dinamómetro de Fuerza Muscular , Músculo Cuádriceps/anatomía & histología , Músculo Cuádriceps/fisiología , Músculo Cuádriceps/efectos de la radiación , Adulto Joven
11.
Artif Organs ; 32(8): 609-13, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18782130

RESUMEN

This study demonstrates in a novel way how volume and shape are restored to denervated degenerated muscles due to a special pattern of electrical stimulation. To this purpose, Spiral Computer Tomography (CT) and special image processing tools were used to develop a method to isolate the rectus femoris from other muscle bellies in the thigh and monitor growth and morphology changes very accurately. During 4 years of electrical stimulation, three-dimensional (3D) reconstructions of the rectus femoris muscles from patients with long-term flaccid paraplegia were made at different points in time. The growth of the muscle and its changes through the time period are seen in the 3D representation and are measured quantitatively. Furthermore, changes in shape are compared with respect to healthy muscles in order to estimate the degree of restoration. The results clearly show a slow but continuing muscle growth induced by electrical stimulation; the increase of volume is accompanied by the return of a quasi-normal muscle shape. This technique allows a unique way of monitoring which provides qualitative and quantitative information on the denervated degenerated muscle behavior otherwise hidden.


Asunto(s)
Terapia por Estimulación Eléctrica , Procesamiento de Imagen Asistido por Computador , Desnervación Muscular , Músculo Cuádriceps/anatomía & histología , Tomografía Computarizada Espiral , Adulto , Humanos , Imagenología Tridimensional , Masculino , Atrofia Muscular/rehabilitación , Tamaño de los Órganos , Paraplejía/rehabilitación , Músculo Cuádriceps/inervación , Factores de Tiempo
12.
Eur J Appl Physiol ; 97(2): 165-73, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16525811

RESUMEN

We investigated the effects of 4 weeks of detraining subsequent to an 8-week electrostimulation (ES) training program on changes in muscle strength, neural and muscular properties of the knee extensor muscles. Nine male subjects followed the training program consisting of 32 sessions of isometric ES training over an 8-week period. All subjects were tested before and after 8 weeks of ES training, and were then retested after 4 weeks of detraining. Quadriceps muscle anatomical cross-sectional area (ACSA) was assessed by ultrasonography imaging. The electromyographic (EMG) activity and muscle activation (i.e., by means of the twitch interpolation technique) obtained during maximal voluntary contractions (MVC) were used to examine neural adaptations. After training, the knee extensor voluntary torque increased significantly by 26%. Torque gains were accompanied by an increase in vastii EMG activity normalized to respective M-wave (+43%), muscle activation (+6%) and quadriceps ACSA (+6%). After detraining, knee extensor MVC, vastii EMG activity, muscle activation and quadriceps ACSA decreased significantly by 9%, 20%, 5% and 3%, respectively. Also, the knee extensor MVC values remained significantly elevated (14%) above baseline levels at the end of the detraining period and this was associated with a larger quadriceps ACSA (+3%) but not with a higher neural activation. We concluded that the voluntary torque losses observed after detraining could be attributed to both neural and muscular alterations. Muscle size preservation could explain the higher knee extensor MVC values observed after the cessation of training compared to those obtained before training, therefore indicating that muscle size changes are slower than neural drive reduction.


Asunto(s)
Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Unión Neuromuscular/fisiología , Esfuerzo Físico/fisiología , Adulto , Estimulación Eléctrica/métodos , Electromiografía , Humanos , Rodilla/inervación , Rodilla/fisiología , Masculino , Músculo Esquelético/anatomía & histología , Músculo Esquelético/inervación , Músculo Cuádriceps/anatomía & histología , Músculo Cuádriceps/fisiología , Factores de Tiempo , Ultrasonografía
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