Science.gov

Sample records for quadriceps strengthening exercises

  1. Implementation of Open and Closed Kinetic Chain Quadriceps Strengthening Exercises after Anterior Cruciate Ligament Reconstruction.

    ERIC Educational Resources Information Center

    Ross, Michael D.; Denegar, Craig R.; Winzenried, Jay A.

    2001-01-01

    Reviews the effects of open kinetic chain (OKC) and closed kinetic chain (CKC) exercise on anterior cruciate ligament (ACL) strain and patellofemoral joint stress, suggesting a combination of the two for quadriceps strengthening after ACL reconstruction. Both OKC and CKC exercises may be modified and implemented for quadriceps strengthening after

  2. Implementation of Open and Closed Kinetic Chain Quadriceps Strengthening Exercises after Anterior Cruciate Ligament Reconstruction.

    ERIC Educational Resources Information Center

    Ross, Michael D.; Denegar, Craig R.; Winzenried, Jay A.

    2001-01-01

    Reviews the effects of open kinetic chain (OKC) and closed kinetic chain (CKC) exercise on anterior cruciate ligament (ACL) strain and patellofemoral joint stress, suggesting a combination of the two for quadriceps strengthening after ACL reconstruction. Both OKC and CKC exercises may be modified and implemented for quadriceps strengthening after…

  3. A new isometric quadriceps-strengthening exercise using EMG-biofeedback

    PubMed Central

    Kesemenli, Cumhur C; Sarman, Hakan; Baran, Tuncay; Memisoglu, Kaya; Binbir, Ismail; Savas, Yilmaz; Isik, Cengiz; Boyraz, Ismail; Koc, Bunyamin

    2014-01-01

    A new isometric contraction quadriceps-strengthening exercise was developed to restore the quadriceps strength lost after knee surgery more rapidly. This study evaluated the results of this new method. Patients were taught to perform the isometric quadriceps-strengthening exercise in the unaffected knee in the supine position, and then they performed it in the affected knee. First, patients were taught the classical isometric quadriceps-strengthening exercise, and then they were taught our new alternative method: “pull the patella superiorly tightly and hold the leg in the same position for 10 seconds”. Afterward, the quadriceps contraction was evaluated using a non-invasive Myomed 932 EMG-biofeedback device (Enraf-Nonius, The Netherlands) with gel-containing 48 mm electrodes (Türklab, The Turkey) placed on both knees. The isometric quadriceps-strengthening exercise performed using our new method had stronger contraction than the classical method (P < 0.01). The new method involving pulling the patella superiorly appears to be a better choice, which can be applied easily, leading to better patient compliance and greater quadriceps force after arthroscopic and other knee surgeries. PMID:25356122

  4. Quadriceps strengthening exercises are effective in improving pain, function and quality of life in patients with osteoarthritis of the knee

    PubMed Central

    Imoto, Aline Mizusaki; Peccin, Maria Stella; Trevisani, Virgínia Fernandes Moça

    2012-01-01

    Objective The purpose of this research was to verify the effectiveness of an eight-week quadriceps strengthening program on pain, function and quality of life of patients with knee osteoarthritis. Methods A hundred patients were randomized into two groups: 1- Exercise Group (ExG) and 2- Orientation Group. The Timed Up and Go (TUG) test, the Numerical Rating Scale (NRS) and the Short Form-36 were used for the assessment. Results Eighty-one patients completed the survey. According to the intention to treat (ITT) analysis, there was statistically significant difference in ExG compared to OG in all the variables assessed. Conclusion The program quadriceps strengthening exercises applied in this randomized clinical trial was effective in improving pain, function and quality of life of patients with knee osteoarthritis. Level of Evidence I, Randomized Clinical Trial. PMID:24453599

  5. Feasibility of using quadriceps-strengthening exercise to improve pain and sleep in a severely demented elder with osteoarthritis - a case report.

    PubMed

    Tsai, Pao-Feng; Richards, Kathy; FitzRandolph, Richard

    2002-10-01

    BACKGROUND: Osteoarthritis (OA) of the knee, which is prevalent among older adults in nursing homes, causes significant pain and suffering, including disturbance of nocturnal sleep. One nonpharmacologic treatment option is quadriceps-strengthening exercise, however, the feasibility of such a treatment for reducing pain from OA in severely demented elders has not been studied. This report describes our test of the feasibility of such an exercise program, together with its effects on pain and sleep, in a severely demented nursing home resident. CASE PRESENTATION: The subject was an elderly man with severe cognitive impairment (Mini-Mental Status Exam score 4) and knee OA (Kellgren-Lawrence radiographic grade 4). He was enrolled in a 5-week, 10-session standardized progressive-resistance training program to strengthen the quadriceps, and completed all sessions. Pain was assessed with the Western Ontario and MacMaster OA Index (WOMAC) pain subscale, and sleep was assessed by actigraphy.The patient was able to perform the exercises, with a revision to the protocol. However, the WOMAC OA pain subscale proved inadequate for measuring pain in a patient with low cognitive functioning, and therefore the effects on pain were inconclusive. Although his sleep improved after the intervention, the influence of his medications and the amount of daytime sleep on his nighttime sleep need to be considered. CONCLUSIONS: A quadriceps-strengthening exercise program for treating OA of the knee is feasible in severely demented elders, although a better outcome measure is needed for pain. PMID:12361479

  6. Comparative study of hamstring and quadriceps strengthening treatments in the management of knee osteoarthritis.

    PubMed

    Al-Johani, Ahmed H; Kachanathu, Shaji John; Ramadan Hafez, Ashraf; Al-Ahaideb, Abdulaziz; Algarni, Abdulrahman D; Meshari Alroumi, Abdulmohesn; Alanezi, Aqeel M

    2014-06-01

    [Purpose] Osteoarthritis (OA) of the knee is the most common form of joint disease. It is one of the major causes of impaired function that reduces quality of life (QOL) worldwide. The purpose of this study was to compare exercise treatments for hamstring and quadriceps strength in the management of knee osteoarthritis. [Subjects and Methods] Forty patients with OA knee, aged 50-65 years were divided into 2 groups. The first group (57.65±4.78 years) received hot packs and performed strengthening exercises for the quadriceps and hamstring, and stretching exercises for the hamstring. The second group (58.15±5.11 years) received hot packs and performed strengthening exercises for only the quadriceps, and stretching exercise for the hamstring. Outcome measures were the WOMAC (Western Ontario and McMaster Universities OA index questionnaire), Visual Analogue Scale (VAS) assessment of pain, the Fifty-Foot Walk Test (FWS), and Handheld dynamometry. [Results] There was a significant difference between the groups. The first group showed a more significant result than the second group. [Conclusion] Strengthening of the hamstrings in addition to strengthening of the quadriceps was shown to be beneficial for improving subjective knee pain, range of motion and decreasing the limitation of functional performance of patients with knee osteoarthritis. PMID:25013274

  7. Comparative Study of Hamstring and Quadriceps Strengthening Treatments in the Management of Knee Osteoarthritis

    PubMed Central

    Al-Johani, Ahmed H; Kachanathu, Shaji John; Ramadan Hafez, Ashraf; Al-Ahaideb, Abdulaziz; Algarni, Abdulrahman D; Meshari Alroumi, Abdulmohsen; Alenazi, Aqeel M.

    2014-01-01

    [Purpose] Osteoarthritis (OA) of the knee is the most common form of joint disease. It is one of the major causes of impaired function that reduces quality of life (QOL) worldwide. The purpose of this study was to compare exercise treatments for hamstring and quadriceps strength in the management of knee osteoarthritis. [Subjects and Methods] Forty patients with OA knee, aged 50–65 years were divided into 2 groups. The first group (57.65±4.78 years) received hot packs and performed strengthening exercises for the quadriceps and hamstring, and stretching exercises for the hamstring. The second group (58.15±5.11 years) received hot packs and performed strengthening exercises for only the quadriceps, and stretching exercise for the hamstring. Outcome measures were the WOMAC (Western Ontario and McMaster Universities OA index questionnaire), Visual Analogue Scale (VAS) assessment of pain, the Fifty-Foot Walk Test (FWS), and Handheld dynamometry. [Results] There was a significant difference between the groups. The first group showed a more significant result than the second group. [Conclusion] Strengthening of the hamstrings in addition to strengthening of the quadriceps was shown to be beneficial for improving subjective knee pain, range of motion and decreasing the limitation of functional performance of patients with knee osteoarthritis. PMID:25013274

  8. Functional changes of human quadriceps muscle injured by eccentric exercise.

    PubMed

    Serrão, F V; Foerster, B; Spada, S; Morales, M M B; Monteiro-Pedro, V; Tannús, A; Salvini, T F

    2003-06-01

    The present study evaluated functional changes of quadriceps muscle after injury induced by eccentric exercise. Maximal isometric torque of quadriceps and the surface electromyography (root mean square, RMS, and median frequency, MDF) of the vastus medialis oblique (VMO) and vastus lateralis (VL) muscles were examined before, immediately after and during the first 7 days after injury. Serum creatine kinase (CK) levels and magnetic resonance imaging (MRI) were used to identify muscle injury. The subject was used as her own control and percent refers to pre-injury data. Experiments were carried out with a sedentary 23-year-old female. Injury was induced by 4 bouts of 15 maximal isokinetic eccentric contractions (angular velocity of 5 /s; range of motion from 40 to 110 of knee flexion). The isometric torque of the quadriceps (knee at 90 flexion) decreased 52% immediately after eccentric exercise and recovered on the 5th day. The highest reduction of RMS occurred on the 2nd day after injury in both VL (63%) and VMO (66%) and only VL recovered to the pre-injury level on the 7th day. Immediately after injury, the MDF decreased by 5 and 3% (VMO and VL, respectively) and recovered one day later. Serum CK levels increased by 109% on the 2nd day and were still increased by 32% on the 7th day. MRI showed large areas of injury especially in the deep region of quadriceps. In conclusion, eccentric exercise decreased the isometric torque and electromyographic signals of quadriceps muscle, which were recovered in one week, despite the muscle regeneration signals. PMID:12792708

  9. Quadriceps and Hamstrings Coactivation During Common Therapeutic Exercises

    PubMed Central

    Begalle, Rebecca L.; DiStefano, Lindsay J.; Blackburn, Troy; Padua, Darin A.

    2012-01-01

    Context Anterior tibial shear force and knee valgus moment increase anterior cruciate ligament (ACL) loading. Muscle coactivation of the quadriceps and hamstrings influences anterior tibial shear force and knee valgus moment, thus potentially influencing ACL loading and injury risk. Therefore, identifying exercises that facilitate balanced activation of the quadriceps and hamstrings might be beneficial in ACL injury rehabilitation and prevention. Objective To quantify and compare quadriceps with hamstrings coactivation electromyographic (EMG) ratios during commonly used closed kinetic chain exercises. Design Cross-sectional study. Setting Research laboratory. Patients or Other Participants Twenty-seven healthy, physically active volunteers (12 men, 15 women; age = 22.1 ± 3.1 years, height = 171.4 ± 10 cm, mass = 72.4 ± 16.7 kg). Intervention(s) Participants completed 9 separate closed chain therapeutic exercises in a randomized order. Main Outcome Measure(s) Surface electromyography quantified the activity level of the vastus medialis (VM), vastus lateralis (VL), medial hamstrings (MH), and biceps femoris (BF) muscles. The quadriceps-to-hamstrings (Q:H) coactivation ratio was computed as the sum of average quadriceps (VM, VL) EMG amplitude divided by the sum of average hamstrings (MH, BF) EMG amplitude for each trial. We used repeated-measures analyses of variance to compare Q:H ratios and individual muscle contributions across exercises (α = .05), then used post hoc Tukey analyses. Results We observed a main effect for exercise (F3,79 = 22.6, P < .001). The post hoc Tukey analyses revealed smaller Q:H ratios during the single-limb dead lift (2.87 ± 1.77) than the single-limb squat (5.52 ± 2.89) exercise. The largest Q:H ratios were observed during the transverse-lunge (7.78 ± 5.51, P < .001), lateral-lunge (9.30 ± 5.53, P < .001), and forward-lunge (9.70 ± 5.90, P < .001) exercises. Conclusions The most balanced (smallest) coactivation ratios were observed during the single-limb dead-lift, lateral-hop, transverse-hop, and lateral band-walk exercises. These exercises potentially could facilitate balanced activation in ACL rehabilitation and injury-prevention programs. They also could be used in postinjury rehabilitation programs in a safe and progressive manner. PMID:22889655

  10. Exercise and Quadriceps Muscle Cooling Time

    PubMed Central

    Long, Blaine C; Cordova, Mitchell L; Brucker, Jody B; Demchak, Timothy J; Stone, Marcus B

    2005-01-01

    Context: Cryotherapy is commonly used for a variety of purposes; however, the body's response to cryotherapy immediately postexercise is unknown. Objective: To investigate the effect of prior exercise on crushed-ice–bag treatment of a large muscle group. Design: 2 × 3 repeated-measures design on depth (1 cm and 2 cm below adipose tissue) and treatment (exercise followed by ice, exercise followed by no ice, and no exercise followed by ice). Setting: Sports Injury Research Laboratory. Patients or Other Participants: Six physically active, uninjured male volunteers. Intervention(s): For the 2 exercise conditions, subjects rode a stationary cycle ergometer at 70% to 80% of their age-predicted maximum heart rate, as calculated by the Karvonen method. For the no-exercise condition, subjects lay supine on a treatment table. The cryotherapy treatment consisted of a 1-kg ice bag applied to the anterior mid thigh. For the no-ice condition, subjects lay supine on a treatment table. Main Outcome Measure(s): Time required for the intramuscular temperatures at the 1-cm and 2-cm depths below adipose tissue to return to pre-exercise baseline and time required to cool the 1-cm and 2-cm depths to 10°C below the pre-exercise temperature. Results: The time to cool the rectus femoris to the pre-exercise temperature using a crushed-ice–bag treatment was reduced by approximately 40 minutes (P < .001). The ice bag cooled the 1-cm and 2-cm depths to the pre-exercise temperature within 7 minutes (P = .38), but the 2-cm tissue depth took nearly 13.5 minutes longer to cool than the 1-cm depth when no ice was applied (P = .001). The 1-cm depth cooled to 10°C below the pre-exercise temperature about 8 minutes sooner than the 2-cm depth, regardless of whether the tissue was exercised or not (P < .001). Exercise shortened the cooling time to 10°C below the pre-exercise temperature by approximately 13 minutes (P = .05). Conclusions: Exercise before cooling with a crushed-ice bag enhanced the removal of intramuscular heat. PMID:16404445

  11. Quadriceps effort during squat exercise depends on hip extensor muscle strategy.

    PubMed

    Bryanton, Megan A; Carey, Jason P; Kennedy, Michael D; Chiu, Loren Z F

    2015-03-01

    Hip extensor strategy, specifically relative contribution of gluteus maximus versus hamstrings, will influence quadriceps effort required during squat exercise, as hamstrings and quadriceps co-contract at the knee. This research examined the effects of hip extensor strategy on quadriceps relative muscular effort (RME) during barbell squat. Inverse dynamics-based torque-driven musculoskeletal models were developed to account for hamstrings co-contraction. Net joint moments were calculated using 3D motion analysis and force platform data. Hamstrings co-contraction was modelled under two assumptions: (1) equivalent gluteus maximus and hamstrings activation (Model 1) and (2) preferential gluteus maximus activation (Model 2). Quadriceps RME, the ratio of quadriceps moment to maximum knee extensor strength, was determined using inverse dynamics only, Model 1 and Model 2. Quadriceps RME was greater in both Models 1 and 2 than inverse dynamics only at barbell loads of 50-90% one repetition maximum. The highest quadriceps RMEs were 120 ± 36% and 87 ± 28% in Models 1 and 2, respectively, which suggests that barbell squats are only feasible using the Model 2 strategy prioritising gluteus maximus versus hamstrings activation. These results indicate that developing strength in both gluteus maximus and quadriceps is essential for lifting heavy loads in squat exercise. PMID:25895990

  12. Core strengthening exercises for low back pain.

    PubMed

    Baerga-Varela, Luis; Abréu Ramos, Antonio M

    2006-01-01

    Core strengthening concepts have gained increased popularity in low back rehabilitation. Traditional low back pain rehabilitation is based on a static spine stability model and is composed mostly of modalities, stretching and strengthening exercises. More recent theories, however, include newer concepts of dynamic spinal stability, coordination and neuromuscular control. Core strengthening exercises incorporate these new concepts. Although more research is necessary, the best available evidence suggests that a core strengthening program may be beneficial in reducing pain scores, functional disability and recurrences of acute low back pain episodes. This article reviews "core" anatomy, physiologic models of spinal stability, effects, of low back pain on spinal stability, evidence-based reasoning behind core strengthening and the basic concepts involved in designing a core strengthening program. PMID:19610550

  13. Effect of exercise-induced arterial hypoxemia on quadriceps muscle fatigue in healthy humans.

    PubMed

    Romer, Lee M; Haverkamp, Hans C; Lovering, Andrew T; Pegelow, David F; Dempsey, Jerome A

    2006-02-01

    The effect of exercise-induced arterial hypoxemia (EIAH) on quadriceps muscle fatigue was assessed in 11 male endurance-trained subjects [peak O2 uptake (VO2 peak) = 56.4 +/- 2.8 ml x kg(-1) x min(-1); mean +/- SE]. Subjects exercised on a cycle ergometer at >or=90% VO2 peak) to exhaustion (13.2 +/- 0.8 min), during which time arterial O2 saturation (Sa(O2)) fell from 97.7 +/- 0.1% at rest to 91.9 +/- 0.9% (range 84-94%) at end exercise, primarily because of changes in blood pH (7.183 +/- 0.017) and body temperature (38.9 +/- 0.2 degrees C). On a separate occasion, subjects repeated the exercise, for the same duration and at the same power output as before, but breathed gas mixtures [inspired O2 fraction (Fi(O2)) = 0.25-0.31] that prevented EIAH (Sa(O2) = 97-99%). Quadriceps muscle fatigue was assessed via supramaximal paired magnetic stimuli of the femoral nerve (1-100 Hz). Immediately after exercise at Fi(O2) 0.21, the mean force response across 1-100 Hz decreased 33 +/- 5% compared with only 15 +/- 5% when EIAH was prevented (P < 0.05). In a subgroup of four less fit subjects, who showed minimal EIAH at Fi(O2) 0.21 (Sa(O2) = 95.3 +/- 0.7%), the decrease in evoked force was exacerbated by 35% (P < 0.05) in response to further desaturation induced via Fi(O2) 0.17 (Sa(O2) = 87.8 +/- 0.5%) for the same duration and intensity of exercise. We conclude that the arterial O2 desaturation that occurs in fit subjects during high-intensity exercise in normoxia (-6 +/- 1% DeltaSa(O2) from rest) contributes significantly toward quadriceps muscle fatigue via a peripheral mechanism. PMID:16166208

  14. Reduction in mdx mouse muscle degeneration by low-intensity endurance exercise: a proteomic analysis in quadriceps muscle of exercised compared with sedentary mdx mice

    PubMed Central

    Fontana, Simona; Schillaci, Odessa; Frinchi, Monica; Giallombardo, Marco; Morici, Giuseppe; Liberto, ValentinaDi; Alessandro, Riccardo; De Leo, Giacomo; Perciavalle, Vincenzo; Belluardo, Natale; Mud, Giuseppa

    2015-01-01

    In our recent study was shown a significant recovery of damaged skeletal muscle of mice with X-linked muscular dystrophy (mdx) following low-intensity endurance exercise, probably by reducing the degeneration of dystrophic muscle. Consequently, in the present work, we aimed to identify proteins involved in the observed reduction in degenerating fibres. To this end, we used proteomic analysis to evaluate changes in the protein profile of quadriceps dystrophic muscles of exercised compared with sedentary mdx mice. Four protein spots were found to be significantly changed and were identified as three isoforms of carbonic anhydrase 3 (CA3) and superoxide dismutase [Cu-Zn] (SODC). Protein levels of CA3 isoforms were significantly up-regulated in quadriceps of sedentary mdx mice and were completely restored to wildtype (WT) mice values, both sedentary and exercised, in quadriceps of exercised mdx mice. Protein levels of SODC were down-regulated in quadriceps of sedentary mdx mice and were significantly restored to WT mice values, both sedentary and exercised, in quadriceps of exercised mdx mice. Western blot data were in agreement with those obtained using proteomic analysis and revealed the presence of one more CA3 isoform that was significantly changed. Based on data found in the present study, it seems that low-intensity endurance exercise may in part contribute to reduce cell degeneration process in mdx muscles, by counteracting oxidative stress. PMID:26182375

  15. Effects of exhaustive incremental treadmill exercise on diaphragm and quadriceps motor potentials evoked by transcranial magnetic stimulation.

    PubMed

    Verin, Eric; Ross, Ewen; Demoule, Alexandre; Hopkinson, Nicholas; Nickol, Annabel; Fauroux, Brigitte; Moxham, John; Similowski, Thomas; Polkey, Michael I

    2004-01-01

    It is unknown whether changes in corticomotor excitability follow exercise in healthy humans. We hypothesized that a fall in the diaphragm and quadriceps motor-evoked potential (MEP) amplitude elicited by transcranial magnetic stimulation of the motor cortex would occur after an incremental exercise task. In 11 healthy subjects, we measured transdiaphragmatic pressure and isometric quadriceps tension in response to supramaximal peripheral magnetic nerve stimulation. MEPs were recorded from these muscles in response to transcranial magnetic stimulation. After baseline measurements, subjects performed a period of submaximal exercise (gentle walking). Measurements were repeated 5 and 20 min after this. The subjects then exercised on a treadmill with an incremental protocol to exhaustion. Transcranial magnetic stimulation was performed at baseline and at 5, 20, 40, and 60 min after exhaustive exercise, and force measurements were obtained at baseline, 20 min, and 60 min. Mean exercise duration was 18 +/- 4 min, and mean maximum heart rate was 172 +/- 10 beats/min. Twitch transdiaphragmatic pressure and twitch isometric quadriceps tension were not different from baseline after exercise, but a significant decrease was observed in diaphragm MEP amplitude 5 and 20 min after exercise (60 +/- 38 and 45 +/- 24%, respectively, of baseline, P = 0.0001). At the same times, the mean quadriceps MEPs were 59 +/- 39 and 74 +/- 32% of baseline (P < 0.0001 and P < 0.01, respectively). Studies using paired stimuli confirmed a likely intracortical mechanism for this depression. Our data confirm significant depression of both diaphragm and quadriceps MEPs after incremental treadmill exercise. PMID:12959961

  16. Dynamics of corticospinal changes during and after high-intensity quadriceps exercise.

    PubMed

    Gruet, Mathieu; Temesi, John; Rupp, Thomas; Levy, Patrick; Verges, Samuel; Millet, Guillaume Y

    2014-08-01

    This study tested the hypothesis that during fatiguing quadriceps exercise, supraspinal fatigue develops late, is associated with both increased corticospinal excitability and inhibition and recovers quickly. Eight subjects performed 20 s contractions [15 s at 50% maximal voluntary contraction (MVC) followed by 5 s MVC] separated by a 10 s rest period until task failure. Transcranial magnetic stimulation (TMS) and electrical femoral nerve stimulation (PNS) were delivered ∼ 2 s apart during 50% MVC, during MVC and after MVC in relaxed muscle. Voluntary activation was assessed by TMS (VATMS) immediately before and after exercise and then three times over a 6 min recovery period. During exercise, MVC and twitch force evoked by PNS in relaxed muscle decreased progressively to 48 ± 8 and 36 ± 16% of control values, respectively (both P < 0.01). Significant changes in voluntary activation assessed by PNS and twitch evoked by TMS during MVC were observed during the last quarter of exercise only (from 96.4 ± 1.7 to 86 ± 13%, P = 0.03 and from 0.76 ± 0.8 to 4.9 ± 4.7% MVC, P = 0.02, from baseline to task failure, respectively). The TMS-induced silent period increased linearly during both MVC (by ∼ 79 ms) and 50% MVC (by ∼ 63 ms; both P < 0.01). Motor-evoked potential amplitude did not change during the protocol at any force levels. Both silent period and VATMS recovered within 2 min postexercise, whereas MVC and twitch force evoked by PNS in relaxed muscle recovered to only 84 ± 9 and 73 ± 17% of control values 6 min after exercise, respectively. In conclusion, high-intensity single-joint quadriceps exercise induces supraspinal fatigue near task failure, with increased intracortical inhibition and, in contrast to previous upper-limb results, unchanged corticospinal excitability. These changes recover rapidly after task failure, emphasizing the need to measure corticospinal adaptations immediately at task failure to avoid underestimation of exercise-induced corticospinal changes. PMID:24907029

  17. Effect of Closed Chain Exercise on Quadriceps Femoris Peak Torque and Functional Performance

    PubMed Central

    Wawrzyniak, John R.; Tracy, James E.; Catizone, Peter V.; Storrow, Rich R.

    1996-01-01

    Objective: To determine the effect of a 6-week leg press training program on quadriceps femoris peak torque and lower extremity functional performance. Design and Setting: A 2 x 3 factorial design. A private university-based outpatient physical therapy clinic was used for testing. The university strength and conditioning center was used for training sessions. Subjects: A volunteer sample of thirty nonathletic, collegeage females participated. All thirty subjects completed the study. Measurements: Subjects were randomly assigned to either a control group (Gcon) or an exercise group that performed isotonic unilateral leg presses through either 0 to 60° (G60) or 0 to 90 ° (G90) of knee flexion. Subjects trained 3 days/wk for 6 weeks using the DAPRE technique. Pre and post isokinetic testing of the quadriceps femoris at 60°/sec and hop tests for distance and time were measured. Results: Both training groups showed significant pre-post increases (p < .05) for: concentric peak torque, eccentric peak torque, and hop test for distance. G\\60 showed a significant decrease in hop test for time values. Significant increases (p < .05) in eccentric peak torque was seen between training groups and the control group, concentric peak torque was significantly greater only in G90 as compared to Gcon, on. No significant differences were observed between G60 and G90 for any of the measured variables. There were no differences between the three groups for any of the functional hop test measurements. Conclusions: Unilateral leg press exercise performed through 0 to 90° of knee flexion increases concentric and eccentric peak torque while training from 0 to 60° improves eccentric torque. No changes in functional performance as measured by hop tests were seen in any groups. Transference between closed kinetic chain (CKC) exercise and open kinetic chain testing was supported, but not between CKC and functional performance testing. ImagesFig 1.Fig 2. PMID:16558420

  18. Force-generating capacities and fatigability of the quadriceps femoris in relation to different exercise modes.

    PubMed

    Ullrich, Boris; Brüggemann, Gert-Peter

    2008-09-01

    In this study, we examined whether different exercise modes provoke functional differences in maximal and explosive force-generating capacities and fatigability of the quadriceps femoris (QF). Additionally, the interaction of different functional capacities was studied in competitive athletes. Ten competitive tennis players and 10 endurance athletes participated in the study. Pre-exercise force-generating capacities were determined during maximal voluntary isometric knee extensions (MVC). Fatigability of the QF was studied using sustained isometric contractions with target loads of 20% and 40% of pre-exercise MVC. Postexercise MVCs were conducted 20 seconds, 1 minute, and 3 minutes post task failure. Muscle activation of the QF during the fatiguing exercises and postexercise MVCs was estimated using surface electromyography. Higher explosive force-generating capacities, but no differences in absolute moments, were detected in tennis players compared with endurance athletes. Fatigability of the QF during both fatiguing tasks was approximately the same in both athletic populations. This was indicated by minor group differences in endurance time, postexercise MVC production, and electromyography (EMG)-estimated muscle activation during fatigue. Variability in endurance time was not significantly associated with pre-exercise force-generating capacities in these competitive athletes. In both athletic populations, recovery of MVC was significantly slower after the fatiguing contraction with 20% of MVC compared with that with 40% of MVC. These results may enhance understanding of plasticity of the neuromuscular system and yield interesting information for the optimization of athletic training programs. Explosive strength training might enhance endurance athletes' explosiveness without decreasing muscle fatigue resistance. The exercise profile of competitive tennis is suggested to act as a sufficient trigger to reach high neuromuscular fatigue resistance but may be inadequate to cause significant gains in absolute muscle strength. PMID:18714233

  19. Relative Activity of Abdominal Muscles during Commonly Prescribed Strengthening Exercises.

    ERIC Educational Resources Information Center

    Willett, Gilbert M.; Hyde, Jennifer E.; Uhrlaub, Michael B.; Wendel, Cara L.; Karst, Gregory M.

    2001-01-01

    Examined the relative electromyographic (EMG) activity of upper and lower rectus abdominis (LRA) and external oblique (EOA) muscles during five abdominal strengthening exercises. Isometric and dynamic EMG data indicated that abdominal strengthening exercises activated various abdominal muscle groups. For the LRA and EOA muscle groups, there were…

  20. Quadriceps muscle blood flow and oxygen availability during repetitive bouts of isometric exercise in simulated sailing.

    PubMed

    Vogiatzis, Ioannis; Andrianopoulos, Vasileios; Louvaris, Zafeiris; Cherouveim, Evgenia; Spetsioti, Stavroula; Vasilopoulou, Maroula; Athanasopoulos, Dimitrios

    2011-07-01

    In this study, we wished to determine whether the observed reduction in quadriceps muscle oxygen availability, reported during repetitive bouts of isometric exercise in simulated sailing efforts (i.e. hiking), is because of restricted muscle blood flow. Six national-squad Laser sailors initially performed three successive 3-min hiking bouts followed by three successive 3-min cycling tests sustained at constant intensities reproducing the cardiac output recorded during each of the three hiking bouts. The blood flow index (BFI) was determined from assessment of the vastus lateralis using near-infrared spectroscopy in association with the light-absorbing tracer indocyanine green dye, while cardiac output was determined from impedance cardiography. At equivalent cardiac outputs (ranging from 10.30.5 to 14.80.86 L min(-1)), the increase from baseline in vastus lateralis BFI across the three hiking bouts (from 1.10.2 to 3.10.6 nM s(-1)) was lower (P = 0.036) than that seen during the three cycling bouts (from 1.10.2 to 7.21.4 nM s(-1)) (Cohen's d: 3.80 nM s(-1)), whereas the increase from baseline in deoxygenated haemoglobin (by ?17.02.9 ?M) (an index of tissue oxygen extraction) was greater (P = 0.006) during hiking than cycling (by ?5.32.7 ?M) (Cohen's d: 4.17 ?M). The results suggest that reduced vastus lateralis muscle oxygen availability during hiking arises from restricted muscle blood flow in the isometrically acting quadriceps muscles. PMID:21590577

  1. Effects of quadriceps strength after static and dynamic whole-body vibration exercise.

    PubMed

    Bush, Jill A; Blog, Gabriel L; Kang, Jie; Faigenbaum, Avery D; Ratamess, Nicholas A

    2015-05-01

    Numerous studies have shown performance benefits including whole-body vibration (WBV) as a training modality or an acute exercise protocol when used as a component of the resistance training program. Some studies have indicated that performing dynamic exercises as compared with static position exercises while exposed to WBV might be beneficial; however, evidence is lacking. Thus, the purpose of this study was to determine if an acute bout of dynamic versus static squats performed during WBV results in increase in quadriceps force production by means of dynamic isokinetic knee extension and flexion exercise. Nonresistance-trained healthy young men and women (N = 21) of 18-25 years participated in 4 protocols with 2-week rest in-between. Protocol 1 consisted of 5 sets of 10 dynamic squats without vibration; Protocol 2: 5 sets of 30-second static squats without vibration; Protocol 3: 5 sets of 10 dynamic squats with 30-Hz WBV for a total of 2.5 minutes; and Protocol 4: 5 sets of 30-second static squats with 30-Hz WBV for a total of 2.5 minutes. Prestrength tests (1 set of 4 repetitions at 100° · s(-1) for the knee extension exercise) was performed within 5 minutes of starting each protocol, and poststrength testing was performed within 1 minute of completing each protocol. Strength outcomes were analyzed by repeated measures analysis of variance with a significance level set at p ≤ 0.05. A significant decrease in strength was observed after dynamic and static squats without WBV (p = 0.002); an increase in strength after dynamic squats with WBV (p = 0.003); and a decrease in strength after static squats with WBV (p = 0.003). The inclusion of WBV to dynamic resistance exercise can be an added modality to increase strength. Whole-body vibration can have varied effects in altering muscle strength in untrained individuals according to the type of resistance training performed. As a dynamic squat with WBV seems to immediately potentiate neuromuscular functioning, the combination of dynamic exercises and WBV could be used as a potential warm-up procedure before resistance exercise. PMID:25268289

  2. Quadriceps Muscle Function After Exercise in Men and Women With a History of Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Kuenze, Christopher M.; Hertel, Jay; Hart, Joseph M.

    2014-01-01

    Context: Sex differences in lower extremity neuromuscular function have been reported after anterior cruciate ligament reconstruction (ACLR). Research evidence supports different levels of fatigability in men and women and between patients with ACLR and healthy controls. The influence of sex on the response to continuous exercise in patients with ACLR is not clear. Objective: To compare quadriceps neuromuscular function after exercise between men and women with ACLR. Design: Descriptive laboratory study. Setting: Laboratory. Patients or Other Participants: Twenty-six active volunteers (13 men [50%]: age = 24.1 ± 4.4 years, height = 179.1 ± 9.8 cm, mass = 80.1 ± 9.4 kg, months since surgery = 43.5 ± 37.0; 13 women [50%]: age = 24.2 ± 5.6 years, height = 163.0 ± 5.9 cm, mass = 62.3 ± 8.3 kg, months since surgery = 45.8 ± 42.7) with a history of unilateral primary ACLR at least 6 months earlier. Intervention(s): Thirty minutes of continuous exercise comprising 5 separate 6-minute cycles, including 5 minutes of uphill walking and 1 minute of body-weight squatting and step-ups. Main Outcome Measure(s): Normalized knee-extension maximal voluntary isometric contraction torque, quadriceps superimposed-burst torque, and quadriceps central activation ratio before and after exercise. We performed separate 2 (sex: men, women) × 2 (time: preexercise, postexercise) repeated-measures analyses of variance for the 3 variables. Separate, independent-samples t tests were calculated to compare preexercise with postexercise change in all dependent variables between sexes. Results: A significant group-by-time interaction was present for knee-extension torque (P = .04). The percentage reduction in knee-extension maximal voluntary isometric contraction torque (men = 1.94%, women = −10.32%; P = .02) and quadriceps central activation ratio (men = −1.45%, women = −8.69%; P = .03) experienced by men was less than that observed in women. Conclusions: In the presence of quadriceps dysfunction, female participants experienced greater-magnitude reductions in quadriceps function after 30 minutes of exercise than male participants. This indicates a reduced ability to absorb knee-joint loads, which may have significant implications for reinjury and joint osteoarthritis in women after ACLR. PMID:25243735

  3. Interactive resistance chair to promote strengthening exercise in older adults.

    PubMed

    Jeong, In Cheol; Finkelstein, Joseph

    2015-01-01

    We developed a strengthening exercise support system which can be remotely managed and clinically supervised via internet. Older adults may potentially benefit from such an exercise system however functionality of this system requires validation before commencement of field studies in older adults. The aim of this study was to introduce and assess validity of a prototype telerehabilitation system supporting computer-assisted home-based strengthening exercise. The system included a resistance chair with a set of movement and physiologic sensors. Real-time feedback on exercise performance was displayed on a touch screen dashboard. Personalized exercise parameters were managed by a rehabilitation team via a designated telerehabilitation site. Assessment of the system demonstrated sufficient validity in real-time identification of exercise performance and cardiovascular parameters. We concluded that the interactive resistance chair has a potential in promoting strengthening exercise and it is warranted for further evaluation in community dwelling older adults. PMID:25991131

  4. High-Impact Exercise Strengthens Men's Bones, Researchers Say

    MedlinePLUS

    ... news/fullstory_157403.html High-Impact Exercise Strengthens Men's Bones, Researchers Say Long-term jogging or tennis ... 22, 2016 MONDAY, Feb. 22, 2016 (HealthDay News) -- Men who engage in high-impact physical activity and ...

  5. Electromyographic activity and rate of muscle fatigue of the quadriceps femoris during cycling exercise in the severe domain.

    PubMed

    Camata, Thiago V; Altimari, Leandro R; Bortolotti, Henrique; Dantas, Jose L; Fontes, Eduardo B; Smirmaul, Bruno P C; Okano, Alexandre H; Chacon-Mikahil, Mara P T; Moraes, Antonio C

    2011-09-01

    This study compared the activation pattern and the fatigue rate among the superficial muscles of the quadriceps femoris (QF) during severe cycling exercise. Peak oxygen consumption (VO(2)peak) and maximal accumulated oxygen Deficit (MAOD) were established by 10 well-trained male cyclists (27.5 ± 4.1 years, 71.0 ± 10.3 kg, 173.4 ± 6.6 cm, mean VO(2)peak 56.7 ± 4.4 ml·kg·min(-1), mean MAOD 5.7 ± 1.1 L). Muscle activity (electromyographic [EMG] signals) was obtained during the supramaximal constant workload test (MAOD) and expressed by root mean square (RMS) and median frequency (MF slope). The RMS of the QF, vastus lateralis (VL) and vastus medialis (VM) muscles were significantly higher than at the beginning after 75% of exercise duration, whereas for the rectus femoris (RF), this was observed after 50% of exercise duration (p ≤ 0.05). The slope of the MF was significantly higher in the RF, followed by the VL and VM (-3.13 ± 0.52 vs. -2.61 ± 0.62 vs. -1.81 ±0.56, respectively; p < 0.05). We conclude that RF may play an important role in limiting performance during severe cycling exercise. PMID:21804424

  6. Effect of L-Glutamine Supplementation on Electromyographic Activity of the Quadriceps Muscle Injured By Eccentric Exercise

    PubMed Central

    Rahmani Nia, Farhad; Farzaneh, Esmail; Damirchi, Arsalan; Shamsi Majlan, Ali

    2013-01-01

    Objective(s): The purpose of the present study was to examine the effects of L-glutamine on electromyographic (EMG) activity of the quadriceps muscle injured by eccentric exercise (EE). Materials and Methods: Seventeen healthy men (age: 22.35±2.27 yr; body mass: 69.91±9.78 kg; height: 177.08±4.32 cm) were randomly and double-blind study with subjects assigned to either an L-glutamine supplementation (n=9) or placebo (n=8) group. The subjects in two groups were asked to take three times during a week for 4 weeks. Each subject was screened for dietary habits before inclusion into the study. Participants performed 6 set to exhaustion eccentric leg extensions at 75% of 1RM and rest intervals were 3 min among sets. Pain Assessment Scale (PAS), EMG activity and range of motion (ROM) measurements were taken before exercise protocol and 24 and 48 hr afterwards. Results: There was no statistically significant difference between groups in perceived muscle soreness (SOR), ROM and EMG activity (P < 0.05). Conclusion: The results indicate that L-glutamine supplementation has no significant effect on muscle injury markers in between groups, although glutamine supplementation attenuated delayed onset muscle soreness (DOMS) effects in sup group. PMID:23997909

  7. Quadriceps Contusion

    MedlinePLUS

    ... it both tear. Quadriceps contusions are common in sports that involve a lot of direct contact, such ... and hockey. They're also a risk in sports where there's a chance of collisions, like soccer ...

  8. Treatment of knee osteoarthritis in relation to hamstring and quadriceps strength.

    PubMed

    Hafez, Ashraf Ramadan; Al-Johani, Ahmed H; Zakaria, Abdul Rahim; Al-Ahaideb, Abdulaziz; Buragadda, Syamala; Melam, Ganeswara Rao; Kachanathu, Shaji J

    2013-11-01

    [Purpose] To assess the effect of hamstring and quadriceps strengthening exercises on pain intensity, gait velocity, maximum isometric strength, and activities of daily living of patients with knee osteoarthritis (OA). [Subjects and Methods] A total of 20 patients with knee OA, 50 to 65 years of age (57.65 ± 4.78 years), received hot packs, strengthening exercises for the quadriceps and the hamstring muscles and stretching exercises for hamstring muscles. Outcome measures included: the Western Ontario and McMaster Universities OA index questionnaire (WOMAC) scores for assessing health status and health outcomes of knee OA; self-reported pain intensity scores, measured using a visual analogue scale; the 50 ft walk test (a measure of gait velocity and function); and handheld dynamometry (a tool used to measure maximum isometric strength of knee extension and flexion). [Results] There was a significant difference between pre- and post-intervention measures of pain intensity, 50 ft walk times, hamstring strength, and quadriceps strength. Significant differences in WOMAC measures were also observed in the subscales of pain, stiffness and physical function, as well as WOMAC total scores. [Conclusion] Strengthening the hamstring muscles in addition to strengthening the quadriceps muscles proved to be beneficial for perceived knee pain, range of motion, and decreasing the limitation of functional performance of patients with knee OA. PMID:24396198

  9. Increases of Quadriceps Inter-Muscular Cross-Correlation and Coherence during Exhausting Stepping Exercise

    PubMed Central

    Chang, Ya-Ju; Chou, Ching-Chieh; Chan, Hsiao-Lung; Hsu, Miao-Ju; Yeh, Ming-Yuh; Fang, Chia-Ying; Chuang, Yu-Fen; Wei, Shun-Hwa; Lien, Hen-Yu

    2012-01-01

    The aim of this study was to examine the change of the intermuscular cross-correlation and coherence of the rectus femoris (RF), vastus medialis (VM) and vastus lateralis (VL) during exhausting stepping exercise. Eleven healthy adults repeated the stepping exercise up to their individual endurance limits (RPE score reached 20), and the cross-correlation and coherence were assessed by surface electromyography (EMG) recordings. The coefficient and time lag of cross-correlation and the coherence areas in the alpha (8–12 Hz), beta (15–30 Hz), gamma (30–60 Hz) and high-gamma (60–150 Hz) bands among the three muscle pairs (RF-VM, RF-VL and VM-VL) were calculated. As muscle fatigue, RF-VM and VM-VL showed increases of coefficients and the shortening of time lags. RF-VM and RF-VL showed increases of beta-band coherence in the ascent and descent phases, respectively. The increased intermuscular cross-correlation and beta-band coherence may be a compensatory strategy for maintaining the coordination of knee synergistic muscles during fatigue due to the fatigue-related disturbance of the corticospinal transmission. Therefore, the intermuscular cross-correlation and beta-band coherence may be a potential index for assessing muscle fatigue and monitoring the central control of motor function during dynamic fatiguing exercise. PMID:23443382

  10. Influence of exercise intensity on atrophied quadriceps muscle in the rat

    PubMed Central

    Tanaka, Shoji; Obatake, Taishi; Hoshino, Koichi; Nakagawa, Takao

    2015-01-01

    [Purpose] The aim of this study was to determine the effect of resistance training on atrophied skeletal muscle in rats based on evidence derived from physical therapy. [Subjects and Methods] Rats were forced to undergo squats as resistance training for 3 weeks after atrophying the rectus femoris muscle by hindlimb suspension for 2 weeks. The intensity of resistance training was adjusted to 50% and 70% of the maximum lifted weight, i.e., 50% of the one-repetition maximum and 70% of the one-repetition maximum, respectively. [Results] Three weeks of training did not alter the one-repetition maximum, and muscle fibers were injured while measuring the one-repetition maximum and reloading. The decrease in cross-sectional area in the rectus femoris muscle induced by unloading for 2 weeks was significantly recovered after training at 70% of the one-repetition maximum. The levels of muscle RING-finger protein-1 mRNA expression were significantly lower in muscles trained at 70% of the one-repetition maximum than in untrained muscles. [Conclusion] These results suggest that high-intensity resistance training can promote atrophic muscle recovery, which provides a scientific basis for therapeutic exercise methods for treatment of atrophic muscle in physical therapy. PMID:26696716

  11. Influence of exercise intensity on atrophied quadriceps muscle in the rat.

    PubMed

    Tanaka, Shoji; Obatake, Taishi; Hoshino, Koichi; Nakagawa, Takao

    2015-11-01

    [Purpose] The aim of this study was to determine the effect of resistance training on atrophied skeletal muscle in rats based on evidence derived from physical therapy. [Subjects and Methods] Rats were forced to undergo squats as resistance training for 3 weeks after atrophying the rectus femoris muscle by hindlimb suspension for 2 weeks. The intensity of resistance training was adjusted to 50% and 70% of the maximum lifted weight, i.e., 50% of the one-repetition maximum and 70% of the one-repetition maximum, respectively. [Results] Three weeks of training did not alter the one-repetition maximum, and muscle fibers were injured while measuring the one-repetition maximum and reloading. The decrease in cross-sectional area in the rectus femoris muscle induced by unloading for 2 weeks was significantly recovered after training at 70% of the one-repetition maximum. The levels of muscle RING-finger protein-1 mRNA expression were significantly lower in muscles trained at 70% of the one-repetition maximum than in untrained muscles. [Conclusion] These results suggest that high-intensity resistance training can promote atrophic muscle recovery, which provides a scientific basis for therapeutic exercise methods for treatment of atrophic muscle in physical therapy. PMID:26696716

  12. Eccentric exercise and delayed onset muscle soreness of the quadriceps induce adjustments in agonist-antagonist activity, which are dependent on the motor task.

    PubMed

    Vila-Chã, C; Hassanlouei, H; Farina, D; Falla, D

    2012-02-01

    This study investigates the effects of eccentric exercise and delayed onset muscle soreness (DOMS) of the quadriceps on agonist-antagonist activity during a range of motor tasks. Ten healthy volunteers (age, mean ± SD, 24.9 ± 3.2 years) performed maximum voluntary contractions (MVC) and explosive isometric contractions of the knee extensors followed by isometric contractions at 2.5, 5, 10, 15, 20, and 30% MVC at baseline, immediately after and 24 h after eccentric exercise of the quadriceps. During each task, force of the knee extensors and surface EMG of the vasti and hamstrings muscles were recorded concurrently. Rate of force development (RFD) was computed from the explosive isometric contraction, and the coefficient of variation of the force (CoV) signal was estimated from the submaximal contractions. Twenty-four hours after exercise, the subjects rated their perceived pain intensity as 4.1 ± 1.2 (score out of 10). The maximum RFD and MVC of the knee extensors was reduced immediately post- and 24 h after eccentric exercise compared to baseline (average across both time points: 19.1 ± 17.1% and 11.9 ± 9.8% lower, respectively, P < 0.05). The CoV for force during the submaximal contractions was greater immediately after eccentric exercise (up to 66% higher than baseline, P < 0.001) and remained higher 24 h post-exercise during the presence of DOMS (P < 0.01). For the explosive and MVC tasks, the EMG amplitude of the vasti muscles decreased immediately after exercise and was accompanied by increased antagonist EMG for the explosive contraction only. On the contrary, reduced force steadiness was accompanied by a general increase in EMG amplitude of the vasti muscles and was accompanied by increased antagonist activity, but only at higher force levels (>15% MVC). This study shows that eccentric exercise and subsequent DOMS of the quadriceps reduce the maximal force, rate of force development and force steadiness of the knee extensors, and is accompanied by different adjustments of agonist and antagonist muscle activities. PMID:22094715

  13. Hemodynamics and O2 uptake during maximal knee extensor exercise in untrained and trained human quadriceps muscle: effects of hyperoxia.

    PubMed

    Mourtzakis, M; Gonzlez-Alonso, J; Graham, T E; Saltin, B

    2004-11-01

    To elucidate the potential limitations on maximal human quadriceps O2 capacity, six subjects trained (T) one quadriceps on the single-legged knee extensor ergometer (1 h/day at 70% maximum workload for 5 days/wk), while their contralateral quadriceps remained untrained (UT). Following 5 wk of training, subjects underwent incremental knee extensor tests under normoxic (inspired O2 fraction = 21%) and hyperoxic (inspired O2 fraction = 60%) conditions with the T and UT quadriceps. Training increased quadriceps muscle mass (2.9 +/- 0.2 to 3.1 +/- 0.2 kg), but did not change fiber-type composition or capillary density. The T quadriceps performed at a greater peak power output than UT, under both normoxia (101 +/- 10 vs. 80 +/- 7 W; P < 0.05) and hyperoxia (97 +/- 11 vs. 81 +/- 7 W; P < 0.05) without further increases with hyperoxia. Similarly, thigh peak O2 consumption, blood flow, vascular conductance, and O2 delivery were greater in the T vs. the UT thigh (1.4 +/- 0.2 vs. 1.1 +/- 0.1 l/min, 8.4 +/- 0.8 vs. 7.2 +/- 0.8 l/min, 42 +/- 6 vs. 35 +/- 4 ml x min(-1) x mmHg(-1), 1.71 +/- 0.18 vs. 1.51 +/- 0.15 l/min, respectively) but were not enhanced with hyperoxia. Oxygen extraction was elevated in the T vs. the UT thigh, whereas arteriovenous O2 difference tended to be higher (78 +/- 2 vs. 72 +/- 4%, P < 0.05; 160 +/- 8 vs. 154 +/- 11 ml/l, respectively; P = 0.098) but again were unaltered with hyperoxia. In conclusion, the present results demonstrate that the increase in quadriceps muscle O2 uptake with training is largely associated with increases in blood flow and O2 delivery, with smaller contribution from increases in O2 extraction. Furthermore, the elevation in peak muscle blood flow and vascular conductance with endurance training seems to be related to an enhanced vasodilatory capacity of the vasculature perfusing the quadriceps muscle that is unaltered by moderate hyperoxia. PMID:15208296

  14. Activity in three parts of the quadriceps recorded isometrically at two different knee angles and during a functional exercise.

    PubMed

    Morrish, G M; Woledge, R C; Haddad, F S

    2003-01-01

    The purpose of this study was to evaluate individual differences in three parts of the quadriceps activated isometrically at 60 degrees and 90 degrees of knee flexion, and during a functional activity involving both concentric and eccentric muscle work. Surface EMG amplitudes were therefore recorded from oblique parts of vastus medialis (VMO) and vastus lateralis (VLO) and from rectus femoris (RF). VMO and VLO showed less activation at 60 degrees than at 90 degrees, but in RF there was no difference between the two angles. In the second experiment, where 11 subjects stepped on and off a stool; these amplitudes were compared with those from a maximal isometric voluntary contraction at 90 degrees of knee flexion. For VMO & VLO the normalised peak amplitude in stepping up was 1.41 +/- 0.12, & 1.46 +/- 0.15 respectively, showing that higher activity is necessary during concentric contractions. These two results suggest that the motor control of VMO/VLO may be different from the bulk of quadriceps. Our findings have implications for patellofemoral function. PMID:12964252

  15. Exercise Strengthens Central Nervous System Modulation of Pain in Fibromyalgia.

    PubMed

    Ellingson, Laura D; Stegner, Aaron J; Schwabacher, Isaac J; Koltyn, Kelli F; Cook, Dane B

    2016-01-01

    To begin to elucidate the mechanisms underlying the benefits of exercise for chronic pain, we assessed the influence of exercise on brain responses to pain in fibromyalgia (FM). Complete data were collected for nine female FM patients and nine pain-free controls (CO) who underwent two functional neuroimaging scans, following exercise (EX) and following quiet rest (QR). Brain responses and pain ratings to noxious heat stimuli were compared within and between groups. For pain ratings, there was a significant (p < 0.05) Condition by Run interaction characterized by moderately lower pain ratings post EX compared to QR (d = 0.39-0.41) for FM but similar to ratings in CO (d = 0.10-0.26), thereby demonstrating that exercise decreased pain sensitivity in FM patients to a level that was analogous to pain-free controls. Brain responses demonstrated a significant within-group difference in FM patients, characterized by less brain activity bilaterally in the anterior insula following QR as compared to EX. There was also a significant Group by Condition interaction with FM patients showing less activity in the left dorsolateral prefrontal cortex following QR as compared to post-EX and CO following both conditions. These results suggest that exercise appeared to stimulate brain regions involved in descending pain inhibition in FM patients, decreasing their sensitivity to pain. Thus, exercise may benefit patients with FM via improving the functional capacity of the pain modulatory system. PMID:26927193

  16. Exercise Strengthens Central Nervous System Modulation of Pain in Fibromyalgia

    PubMed Central

    Ellingson, Laura D.; Stegner, Aaron J.; Schwabacher, Isaac J.; Koltyn, Kelli F.; Cook, Dane B.

    2016-01-01

    To begin to elucidate the mechanisms underlying the benefits of exercise for chronic pain, we assessed the influence of exercise on brain responses to pain in fibromyalgia (FM). Complete data were collected for nine female FM patients and nine pain-free controls (CO) who underwent two functional neuroimaging scans, following exercise (EX) and following quiet rest (QR). Brain responses and pain ratings to noxious heat stimuli were compared within and between groups. For pain ratings, there was a significant (p < 0.05) Condition by Run interaction characterized by moderately lower pain ratings post EX compared to QR (d = 0.39–0.41) for FM but similar to ratings in CO (d = 0.10–0.26), thereby demonstrating that exercise decreased pain sensitivity in FM patients to a level that was analogous to pain-free controls. Brain responses demonstrated a significant within-group difference in FM patients, characterized by less brain activity bilaterally in the anterior insula following QR as compared to EX. There was also a significant Group by Condition interaction with FM patients showing less activity in the left dorsolateral prefrontal cortex following QR as compared to post-EX and CO following both conditions. These results suggest that exercise appeared to stimulate brain regions involved in descending pain inhibition in FM patients, decreasing their sensitivity to pain. Thus, exercise may benefit patients with FM via improving the functional capacity of the pain modulatory system. PMID:26927193

  17. The effects of gluteus muscle strengthening exercise and lumbar stabilization exercise on lumbar muscle strength and balance in chronic low back pain patients

    PubMed Central

    Jeong, Ui-Cheol; Sim, Jae-Heon; Kim, Cheol-Yong; Hwang-Bo, Gak; Nam, Chan-Woo

    2015-01-01

    [Purpose] The aim of this study was to examine the effects of exercise to strengthen the muscles of the hip together with lumbar segmental stabilization exercise on the lumbar disability index, lumbar muscle strength, and balance. [Subjects and Methods] This study randomly and equally assigned 40 participants who provided written consent to participate in this study to a lumbar segmental stabilization exercise plus exercise to strengthen the muscles of the gluteus group (SMG + LES group) and a lumbar segmental stabilization exercise group. [Results] Each evaluation item showed a statistically significant effect. [Conclusion] Clinical application of exercise in this study showed that lumbar segmental stabilization exercise plus exercise to strengthen the muscles of the gluteus resulted in a greater decrease in low back pain disability index and increase in lumbar muscle strength and balance ability than lumbar segmental stabilization exercise in chronic low back pain patients receiving the exercise treatments during the same period. PMID:26834359

  18. Exercise for patients with osteoporosis: management of vertebral compression fractures and trunk strengthening for fall prevention.

    PubMed

    Sinaki, Mehrsheed

    2012-11-01

    Maintenance of bone health and quality requires mechanical strain, but the mechanical force needs to be within the bone's biomechanical competence. In osteoporosis, compression of vertebral bodies can be insidious. Therefore, absence of pain does not necessarily indicate absence of vertebral microfracture and deformity. Further, patients with previous vertebral fractures are at risk for further vertebral fractures and their associated morbidity. Exercise is a part of the comprehensive management of patients with osteoporosis and has been associated with improvement of quality of life and lowered risk of future fracture. The exercise prescription needs to match the needs of the patient. If exercise is not prescribed properly, then it may have negative consequences. In general, an exercise program, therapeutic or recreational, needs to address flexibility, muscle strength, core stability, cardiovascular fitness, and gait steadiness. As with pharmacotherapy, therapeutic exercises need to be individualized on the basis of musculoskeletal status and an individual's exercise interest. In osteoporosis, axial strength and stability are of primary importance. In particular, a spinal extensor strengthening program should be performed with progressive measured resistance as tolerated. To address falls and fractures, an exercise program should also include balance and lower extremity strength training. Proper dosing of oral cholecalciferol and calcium supplements can enhance the effect of strengthening exercises. Finally, a coordinated approach, such as the Spinal Proprioception Extension Exercise Dynamic (SPEED) program, can improve back extensor strength, the level of physical activity, and locomotion, and reduce back pain and fear and risk of falls. PMID:23174554

  19. Isolated quadriceps training increases maximal exercise capacity in chronic heart failure: The role of skeletal muscle convective and diffusive oxygen transport

    PubMed Central

    Esposito, Fabio; Reese, Van; Shabetai, Ralph; Wagner, Peter D.; Richardson, Russell S.

    2011-01-01

    Objectives This study sought to elucidate the mechanisms responsible for the benefits of small muscle mass exercise training in patients with chronic heart failure (CHF). Background How central cardiorespiratory and/or peripheral skeletal muscle factors are altered with small muscle mass training in CHF is unknown. Methods We studied muscle structure and oxygen (O2) transport and metabolism at maximal cycle (whole body) and knee-extensor exercise (KE) (small muscle mass) in 6 healthy controls and 6 patients with CHF who then performed 8 weeks of KE training (both legs, separately) and repeated these assessments. Results Pre-training cycling and KE peak leg O2 uptake (VO2peak) were ~17% and ~15% lower, respectively, in the patients compared to controls. Structurally, KE training increased quadriceps muscle capillarity and mitochondrial density by ~21 and ~25%, respectively. Functionally, despite not altering maximal cardiac output, KE training increased maximal O2 delivery (~54%), arterial-venous O2 (a–v O2) difference (~10%), and muscle O2 diffusive conductance (DMO2) (~39%) (assessed during KE), thereby increasing single leg VO2peak by ~53%, to a level exceeding that of the untrained controls. Post-training, during maximal cycling, O2 delivery (~40%), a–v O2 difference (~15%), and DMO2 (~52%) all increased, yielding an increase in VO2peak of ~40%, matching the controls. Conclusions In the face of continued central limitations, clear improvements in muscle structure, peripheral convective and diffusive O2 transport, and subsequently O2 utilization support the efficacy of local skeletal muscle training as a powerful approach to combat exercise intolerance in CHF. PMID:21920265

  20. Quadriceps exercise intolerance in patients with chronic obstructive pulmonary disease: the potential role of altered skeletal muscle mitochondrial respiration.

    PubMed

    Gifford, Jayson R; Trinity, Joel D; Layec, Gwenael; Garten, Ryan S; Park, Song-Young; Rossman, Matthew J; Larsen, Steen; Dela, Flemming; Richardson, Russell S

    2015-10-15

    This study sought to determine if qualitative alterations in skeletal muscle mitochondrial respiration, associated with decreased mitochondrial efficiency, contribute to exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). Using permeabilized muscle fibers from the vastus lateralis of 13 patients with COPD and 12 healthy controls, complex I (CI) and complex II (CII)-driven State 3 mitochondrial respiration were measured separately (State 3:CI and State 3:CII) and in combination (State 3:CI+CII). State 2 respiration was also measured. Exercise tolerance was assessed by knee extensor exercise (KE) time to fatigue. Per milligram of muscle, State 3:CI+CII and State 3:CI were reduced in COPD (P < 0.05), while State 3:CII and State 2 were not different between groups. To determine if this altered pattern of respiration represented qualitative changes in mitochondrial function, respiration states were examined as percentages of peak respiration (State 3:CI+CII), which revealed altered contributions from State 3:CI (Con 83.7 ± 3.4, COPD 72.1 ± 2.4%Peak, P < 0.05) and State 3:CII (Con 64.9 ± 3.2, COPD 79.5 ± 3.0%Peak, P < 0.05) respiration, but not State 2 respiration in COPD. Importantly, a diminished contribution of CI-driven respiration relative to the metabolically less-efficient CII-driven respiration (CI/CII) was also observed in COPD (Con 1.28 ± 0.09, COPD 0.81 ± 0.05, P < 0.05), which was related to exercise tolerance of the patients (r = 0.64, P < 0.05). Overall, this study indicates that COPD is associated with qualitative alterations in skeletal muscle mitochondria that affect the contribution of CI and CII-driven respiration, which potentially contributes to the exercise intolerance associated with this disease. PMID:26272320

  1. Effect of a muscle strengthening exercise program for pelvic control on gait function of stroke patients.

    PubMed

    Park, Byoung-Sun; Kim, Ju-Hyun; Kim, Mee-Young; Lee, Lim-Kyu; Yang, Seung-Min; Jeon, Hye-Joo; Lee, Won-Deok; Noh, Ji-Woong; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Kim, Ju-Young; Kim, Junghwan

    2015-03-01

    [Purpose] The purpose of this study was to investigate the effects of strengthening exercises for the hip extensors on the gait performance and stability of patients with hemiplegia. [Subjects and Methods] The subjects were fifteen stroke patients (ten males, five females). The experimental subjects performed a hip extensor strengthening exercise (HESE) program for a total of four weeks. [Results] The experimental subjects showed significant improvements after the HESE program. Especially, walking speed and the affected side stance phase time significantly increased after the HESE program. Furthermore, the affected side stride length and symmetry index in the stance phase significantly increased after HESE program. [Conclusion] These results suggest that the HESE program may, in part, help to improve gait performance ability and stabilize physical disability after stroke. PMID:25931698

  2. Effect of a muscle strengthening exercise program for pelvic control on gait function of stroke patients

    PubMed Central

    Park, Byoung-Sun; Kim, Ju-Hyun; Kim, Mee-Young; Lee, Lim-Kyu; Yang, Seung-Min; Jeon, Hye-Joo; Lee, Won-Deok; Noh, Ji-Woong; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Kim, Ju-Young; Kim, Junghwan

    2015-01-01

    [Purpose] The purpose of this study was to investigate the effects of strengthening exercises for the hip extensors on the gait performance and stability of patients with hemiplegia. [Subjects and Methods] The subjects were fifteen stroke patients (ten males, five females). The experimental subjects performed a hip extensor strengthening exercise (HESE) program for a total of four weeks. [Results] The experimental subjects showed significant improvements after the HESE program. Especially, walking speed and the affected side stance phase time significantly increased after the HESE program. Furthermore, the affected side stride length and symmetry index in the stance phase significantly increased after HESE program. [Conclusion] These results suggest that the HESE program may, in part, help to improve gait performance ability and stabilize physical disability after stroke. PMID:25931698

  3. PERCEIVED LOADING AND MUSCLE ACTIVITY DURING HIP STRENGTHENING EXERCISES: COMPARISON OF ELASTIC RESISTANCE AND MACHINE EXERCISES

    PubMed Central

    Jakobsen, Markus Due; Thorborg, Kristian; Sundstrup, Emil; Jay, Kenneth; Andersen, Lars L.

    2013-01-01

    Objective: Decreased hip muscle strength is frequently reported in patients with hip injury or pathology. Furthermore, soccer players suffering from groin injury show decreased strength of hip muscles. Estimating 10?repetition maximum can be time?consuming and difficult, thus, using the Borg category rating 10 scale (Borg CR10 scale) can be a useful tool for estimating the intensity of exercise. The aims of this study were 1) to investigate the feasibility of the use of the Borg CR10 scale for rating strength training intensity of the hip abductor and hip adductor muscles, and 2) to compare hip muscle activity during hip abduction and hip adduction exercises using elastic resistance and isotonic machines, using electromyography (EMG). Methods: EMG activity was recorded from 11 muscles at the hip, thigh and trunk during hip adduction and hip abduction exercises in 16 untrained women, using elastic resistance and isotonic exercise machines. These recordings were normalized to maximal voluntary contraction (MVC) EMG (nEMG). The exercises were performed at four levels of perceived loading reported using the Borg CR10: light (Borg ?2), moderate (Borg >2<5), heavy (Borg ?5<7) and near maximum (Borg ?7). Results: Moderate to strong associations were observed between perceived loading and nEMG obtained during the adduction exercise with elastic resistance (r=0.80.3) as well as in machine (r=0.690.55) and the abduction exercise with elastic resistance (r=0.660.29) as well as in machine (r =0.620.54). The abduction exercise performed with elastic resistance displayed significantly higher gluteus medius nEMG recruitment than the in machine exercise. Conclusions: The results of this study show that the Borg CR10 scale can be a useful tool for estimating intensity levels during resistance training of the hip adductor and hip abductor muscles. Although elastic resistance and exercise machine seem equally effective for recruiting muscle activity of the hip adductors, the elastic resistance condition was able to demonstrate greater muscle recruitment than the exercise machine during hip abduction. PMID:24377067

  4. The effects of respiratory muscle strengthening exercise using a sling on the amount of respiration.

    PubMed

    Yi, Seung-Ju; Kim, Jin-Seop

    2015-07-01

    [Purpose] The purpose of this study was to present aerobic exercise that can be performed together with respiratory muscle strength training and examine whether the vital capacity of individuals can be enhanced when respiratory muscle strength training is conducted together with aerobic exercise. [Subjects and Methods] The subjects were 10 male students and 8 female students. The sling exercise method was used to conduct three types of training to strengthen the muscles around the shoulder joints. A maximal respiratory quotient measurement device was used to measure the vital capacity of the subjects five times. [Results] There was a significant difference in each respiratory training time point compared with before the performance of respiratory training. [Conclusion] This study presented respiratory muscle strength training using a sling as a training method for respiratory training. PMID:26311937

  5. The effects of respiratory muscle strengthening exercise using a sling on the amount of respiration

    PubMed Central

    Yi, Seung-Ju; Kim, Jin-Seop

    2015-01-01

    [Purpose] The purpose of this study was to present aerobic exercise that can be performed together with respiratory muscle strength training and examine whether the vital capacity of individuals can be enhanced when respiratory muscle strength training is conducted together with aerobic exercise. [Subjects and Methods] The subjects were 10 male students and 8 female students. The sling exercise method was used to conduct three types of training to strengthen the muscles around the shoulder joints. A maximal respiratory quotient measurement device was used to measure the vital capacity of the subjects five times. [Results] There was a significant difference in each respiratory training time point compared with before the performance of respiratory training. [Conclusion] This study presented respiratory muscle strength training using a sling as a training method for respiratory training. PMID:26311937

  6. The effects of ankle joint muscle strengthening and proprioceptive exercise programs accompanied by functional electrical stimulation on stroke patients’ balance

    PubMed Central

    Kim, Kyunghoon; Lee, Sukmin; Kim, Donghoon; Kim, Kyou Sik

    2015-01-01

    [Purpose] The purpose of the present study was to examine the effects of ankle joint muscle strengthening and proprioceptive exercises accompanied by functional electrical stimulation on stroke patients’ balance ability. [Methods] For six weeks beginning in April 2015, 22 stroke patients receiving physical therapy at K Hospital located in Gyeonggi-do were divided into a functional electrical stimulation (FES), ankle proprioceptive exercise and ankle joint muscle strengthening exercise group (FPS group) of 11 patients and an FES and stretching exercise group (FS group) of 11 patients. The stimulation and exercises were conducted for 30 min per day, five days per week for six weeks. Balance ability was measured using a BioRescue and the Berg balance scale, functional reach test, and the timed up-and-go test were also used as clinical evaluation indices. Repeated measures ANOVA was conducted to examine differences between before the exercises and at three and six weeks after beginning the exercises within each group, and the amounts of change between the two groups were compared. [Results] In the comparison within each group, both groups showed significant differences between before and after the experiment in all the tests and comparison between the groups showed that greater improvement was seen in all values in the FPS group. [Conclusion] In the present study, implementing FES and stretching exercises plus ankle joint muscle strengthening and proprioceptive exercises was more effective at improving stroke patients balance ability than implementing only FES and stretching exercises. PMID:26504337

  7. A new silver robot platform for the elderly and the handicapped: Spiderbot TM-posture balancing and muscle strengthening exercises

    NASA Astrophysics Data System (ADS)

    Pervez, Aslam; Farahani, Hossein S.; Jeong, Seung-Gweon; Kim, Hyunho; Ryu, Jeha

    2005-12-01

    By using a new type of silver robot called SpiderBot TM, posture balancing and muscle strengthening exercises were presented. Unlike mobile robots on a floor, SpiderBot TM is conceptualized to generate full mobility in a room and to have higher payload while generating six degrees-of-freedom for assisting daily lives of the elderly and the handicapped. A preliminary prototype of SpiderBot TM has been constructed by using incompletely restrained wire mechanism and simple control algorithms were implemented for two types of exercises for elderly people's health improvement. One is a posture balancing exercise that prevents from falling to any directions. And the other is muscle strengthening exercise that uses the SpiderBot TM as a weight lifting mechanism. Preliminary experimental results show that the proposed new silver robot platform is used for such exercises.

  8. The effects of gluteus maximus and abductor hallucis strengthening exercises for four weeks on navicular drop and lower extremity muscle activity during gait with flatfoot

    PubMed Central

    Goo, Young-Mi; Kim, Tae-Ho; Lim, Jin-Yong

    2016-01-01

    [Purpose] The purpose of the present study is to examine the effects of abductor hallucis and gluteus maximus strengthening exercises on pronated feet. [Subjects and Methods] The present study was conducted with 18 adults without no history of surgery on the foot or ankle. One group performed both gluteus maximus strengthening exercises and abductor hallucis strengthening exercises, while the other group performed only abductor hallucis strengthening exercises five times per week for four weeks. [Results] The group that performed both gluteus maximus and abductor hallucis strengthening exercises showed smaller values in the height of navicular drop than the group that performed only abductor hallucis strengthening exercises. The muscle activity of the gluteus maximus and the vastus medialis increased during heel-strike in the group that added gluteus maximus exercises, and the muscle activity of the abductor hallucis significantly increased in both groups. [Conclusion] Given the results of the present study, it can be suggested that strengthening the gluteus maximus while also performing exercises to correct the pronated foot is an effective method for achieving normal gait. PMID:27134383

  9. The effects of gluteus maximus and abductor hallucis strengthening exercises for four weeks on navicular drop and lower extremity muscle activity during gait with flatfoot.

    PubMed

    Goo, Young-Mi; Kim, Tae-Ho; Lim, Jin-Yong

    2016-03-01

    [Purpose] The purpose of the present study is to examine the effects of abductor hallucis and gluteus maximus strengthening exercises on pronated feet. [Subjects and Methods] The present study was conducted with 18 adults without no history of surgery on the foot or ankle. One group performed both gluteus maximus strengthening exercises and abductor hallucis strengthening exercises, while the other group performed only abductor hallucis strengthening exercises five times per week for four weeks. [Results] The group that performed both gluteus maximus and abductor hallucis strengthening exercises showed smaller values in the height of navicular drop than the group that performed only abductor hallucis strengthening exercises. The muscle activity of the gluteus maximus and the vastus medialis increased during heel-strike in the group that added gluteus maximus exercises, and the muscle activity of the abductor hallucis significantly increased in both groups. [Conclusion] Given the results of the present study, it can be suggested that strengthening the gluteus maximus while also performing exercises to correct the pronated foot is an effective method for achieving normal gait. PMID:27134383

  10. The development and evaluation of a program for leg-strengthening exercises and balance assessment using Kinect

    PubMed Central

    Choi, Jin-Seung; Kang, Dong-Won; Seo, Jeong-Woo; Kim, Dae-Hyeok; Yang, Seung-Tae; Tack, Gye-Rae

    2016-01-01

    [Purpose] In this study, a program was developed for leg-strengthening exercises and balance assessment using Microsoft Kinect. [Subjects and Methods] The program consists of three leg-strengthening exercises (knee flexion, hip flexion, and hip extension) and the one-leg standing test (OLST). The program recognizes the correct exercise posture by comparison with the range of motion of the hip and knee joints and provides a number of correct action examples to improve training. The program measures the duration of the OLST and presents this as the balance-age. The accuracy of the program was analyzed using the data of five male adults. [Results] In terms of the motion recognition accuracy, the sensitivity and specificity were 95.3% and 100%, respectively. For the balance assessment, the time measured using the existing method with a stopwatch had an absolute error of 0.37 sec. [Conclusion] The developed program can be used to enable users to conduct leg-strengthening exercises and balance assessments at home. PMID:26957724

  11. The development and evaluation of a program for leg-strengthening exercises and balance assessment using Kinect.

    PubMed

    Choi, Jin-Seung; Kang, Dong-Won; Seo, Jeong-Woo; Kim, Dae-Hyeok; Yang, Seung-Tae; Tack, Gye-Rae

    2016-01-01

    [Purpose] In this study, a program was developed for leg-strengthening exercises and balance assessment using Microsoft Kinect. [Subjects and Methods] The program consists of three leg-strengthening exercises (knee flexion, hip flexion, and hip extension) and the one-leg standing test (OLST). The program recognizes the correct exercise posture by comparison with the range of motion of the hip and knee joints and provides a number of correct action examples to improve training. The program measures the duration of the OLST and presents this as the balance-age. The accuracy of the program was analyzed using the data of five male adults. [Results] In terms of the motion recognition accuracy, the sensitivity and specificity were 95.3% and 100%, respectively. For the balance assessment, the time measured using the existing method with a stopwatch had an absolute error of 0.37 sec. [Conclusion] The developed program can be used to enable users to conduct leg-strengthening exercises and balance assessments at home. PMID:26957724

  12. A randomised controlled feasibility study investigating the use of eccentric and concentric strengthening exercises in the treatment of rotator cuff tendinopathy

    PubMed Central

    Adams, Nicola

    2014-01-01

    Objectives: To conduct a feasibility study to compare concentric and eccentric rotator cuff strengthening exercises for rotator cuff tendinopathy. Methods: A total of 11 patients with rotator cuff tendinopathy who were on the waiting list for arthroscopic subacromial decompression surgery were randomised to perform eccentric rotator cuff strengthening exercises, concentric strengthening exercises or no exercises. Patients were evaluated in terms of levels of pain and function using the Oxford Shoulder Score and a Visual Analogue Scale initially, at 4 weeks and at 8 weeks. Results: The study design was found to be acceptable to patients and achieved a high level of 86% compliance. The drop-out rate was 0%. Two patients performing eccentric strengthening exercises improved sufficiently to cancel their planned surgery. Conclusion: Further research in this area is recommended. The study design was feasible and power calculations have been conducted to aid future research planning. PMID:26770702

  13. The Effect of NeuroMuscular Electrical Stimulation on Quadriceps Strength and Knee Function in Professional Soccer Players: Return to Sport after ACL Reconstruction

    PubMed Central

    Taradaj, J.; Halski, T.; Kucharzewski, M.; Walewicz, K.; Smykla, A.; Ozon, M.; Slupska, L.; Dymarek, R.; Ptaszkowski, K.; Rajfur, J.; Pasternok, M.

    2013-01-01

    The aim of this study was to assess the clinical efficacy and safety of NMES program applied in male soccer players (after ACL reconstruction) on the quadriceps muscle. The 80 participants (NMES = 40, control = 40) received an exercise program, including three sessions weekly. The individuals in NMES group additionally received neuromuscular electrical stimulation procedures on both right and left quadriceps (biphasic symmetric rectangular pulses, frequency of impulses: 2500 Hz, and train of pulses frequency: 50 Hz) three times daily (3 hours of break between treatments), 3 days a week, for one month. The tensometry, muscle circumference, and goniometry pendulum test (follow-up after 1 and 3 months) were applied. The results of this study show that NMES (in presented parameters in experiment) is useful for strengthening the quadriceps muscle in soccer athletes. There is an evidence of the benefit of the NMES in restoring quadriceps muscle mass and strength of soccer players. In our study the neuromuscular electrical stimulation appeared to be safe for biomechanics of knee joint. The pathological changes in knee function were not observed. This trial is registered with Australian and New Zealand Clinical Trials Registry ACTRN12613001168741. PMID:24381943

  14. Effects of consecutive application of stretching, Schroth, and strengthening exercises on Cobb’s angle and the rib hump in an adult with idiopathic scoliosis

    PubMed Central

    Yang, Jae-Man; Lee, Jung-Hoon; Lee, Dae-Hee

    2015-01-01

    [Purpose] To report the effects of consecutive application of stretching, Schroth, and strengthening exercises in an adult with idiopathic scoliosis. [Subject] A 26-year-old woman with idiopathic scoliosis, Cobb’s angle of 20.51°, and back pain. [Methods] The exercise program consisted of 3 sessions: 10 minutes of stretching exercises, 20 minutes of Schroth exercises, and 10 minutes of strengthening exercises. This program was implemented 3 times a week, for 8 weeks. [Results] The thoracic Cobb’s angle decreased from 20.51° to 16.35°, and the rib hump decreased from 15° to 9°. [Conclusion] Consecutive application of stretching, Schroth, and strengthening exercises may help reduce Cobb’s angle and the rib hump in adults with idiopathic scoliosis. PMID:26355577

  15. Effect of grip strength and grip strengthening exercises on instantaneous bat velocity of collegiate baseball players.

    PubMed

    Hughes, Shawn S; Lyons, Brian C; Mayo, Jerry J

    2004-05-01

    Bat velocity is considered to be an important factor for successful hitting. The relationship between grip strength and bat velocity has not been conclusively established. The purposes of this study were to determine the relationship of grip strength to bat velocity and to ascertain whether the performance of resistance training exercises designed to specifically target the forearms and grip would significantly alter bat velocity. The subjects for this study were 23 male members (mean +/- SD, age = 19.7 +/- 1.3 years, height = 182.5 +/- 5.9 cm, weight = 85.4 +/- 15.5 kg, experience = 14.4 +/- 1.7 years) of a varsity baseball team at a National Collegiate Athletic Association Division II school. The Jamar hand dynamometer was used to test grip strength, and the SETPRO Rookie was used to measure instantaneous bat velocity at the point of contact with the ball. Subjects were randomly divided into an experimental group and a control group. For 6 weeks, both groups participated in their usual baseball practice sessions, but the experimental group also performed extra forearm and grip strengthening exercises, whereas the control group did not. Pretest and posttest correlations between grip strength and bat velocity revealed no significant relationship between grip strength and bat velocity (pretest r = 0.054, p = 0.807; posttest r = 0.315, p = 0.145). A dependent t-test performed on all subjects revealed that a significant (p = 0.001) increase in bat velocity did occur over the course of the study. A covariate analysis, employing pretest bat velocity as the covariate, revealed no significant difference (p = 0.795) in posttest bat velocity scores between the experimental and control groups. Thus, increases in bat velocity occurred, but the differences were similar for both the experimental and control groups. The findings of this study suggest that grip strength and bat velocity are not significantly related, and that the allocation of time and energy for added training of the forearms in order to improve grip strength for the purpose of increasing bat velocity may not be warranted. PMID:15142011

  16. Central and peripheral quadriceps fatigue in congestive heart failure☆

    PubMed Central

    Hopkinson, Nicholas S.; Dayer, Mark J.; Antoine-Jonville, Sophie; Swallow, Elisabeth B.; Porcher, Raphael; Vazir, Ali; Poole-Wilson, Philip; Polkey, Michael I.

    2013-01-01

    Aims The clinical syndrome of heart failure includes exercise limitation that is not directly linked to measures of cardiac function. Quadriceps fatigability may be an important component of this and this may arise from peripheral or central factors. Methods and results We studied 10 men with CHF and 10 healthy age-matched controls. Compared with a rest condition, 10 min after incremental maximal cycle exercise, twitch quadriceps force in response to supramaximal magnetic femoral nerve stimulation fell in both groups (CHF 14.1% ± 18.1%, p = 0.037; Control: 20.8 ± 11.0%, p < 0.001; no significant difference between groups). There was no significant change in quadriceps maximum voluntary contraction voluntary force. The difference in the motor evoked potential (MEP) response to transcranial magnetic stimulation of the motor cortex between rest and exercise conditions at 10 min, normalised to the peripheral action potential, also fell significantly in both groups (CHF: 27.3 ± 38.7%, p = 0.037; Control: 41.1 ± 47.7%, p = 0.024). However, the fall in MEP was sustained for a longer period in controls than in patients (p = 0.048). Conclusions The quadriceps is more susceptible to fatigue, with a similar fall in TwQ occurring in CHF patients at lower levels of exercise. This is associated with no change in voluntary activation but a lesser degree of depression of quadriceps motor evoked potential. PMID:22795722

  17. The effects of a community-centered muscle strengthening exercise program using an elastic band on the physical abilities and quality of life of the rural elderly.

    PubMed

    Park, So-Yeon; Kim, Jin-Kyung; Lee, Seong-A

    2015-07-01

    [Purpose] The purpose of this study was to examine the effects of a muscle strengthening exercise program using an elastic band on changes in the physical abilities and quality of life of the rural elderly. [Subjects] The subjects of this study were 46 elderly people (8 males, 38 females) aged 65 or older, who lived in a rural area and managed their daily lives independently. [Methods] The study's exercise program was conducted 16 times for 80 minutes each session over an eight-week period. This program consisted of several exercises to strengthen muscular endurance and improve balance ability based on exercises using Thera-bands. The physical abilities of the subjects were divided into muscular endurance, upper-extremity flexibility, balance, and low-extremity agility. Each ability was measured to compare the effects of the exercise program. In addition, the Korean version of the World Health Organization Quality of Life (WHOQOL)-BREF questionnaire was used to examine changes in the subjects' quality of life. [Results] The subjects showed improvements in muscular endurance, balance, and low-extremity agility. They also exhibited an overall statistically significant improvement in quality of life scores after the exercise program. In terms of the main items, changes were observed in the areas of psychological relations, social relations, and environment. [Conclusion] The community-centered muscle strengthening exercise program using the elastic band was found to improve muscular endurance, balance, agility, and quality of life of rural elderly subjects. PMID:26311926

  18. The effects of a community-centered muscle strengthening exercise program using an elastic band on the physical abilities and quality of life of the rural elderly

    PubMed Central

    Park, So-Yeon; Kim, Jin-Kyung; Lee, Seong-A

    2015-01-01

    [Purpose] The purpose of this study was to examine the effects of a muscle strengthening exercise program using an elastic band on changes in the physical abilities and quality of life of the rural elderly. [Subjects] The subjects of this study were 46 elderly people (8 males, 38 females) aged 65 or older, who lived in a rural area and managed their daily lives independently. [Methods] The study’s exercise program was conducted 16 times for 80 minutes each session over an eight-week period. This program consisted of several exercises to strengthen muscular endurance and improve balance ability based on exercises using Thera-bands. The physical abilities of the subjects were divided into muscular endurance, upper-extremity flexibility, balance, and low-extremity agility. Each ability was measured to compare the effects of the exercise program. In addition, the Korean version of the World Health Organization Quality of Life (WHOQOL)-BREF questionnaire was used to examine changes in the subjects’ quality of life. [Results] The subjects showed improvements in muscular endurance, balance, and low-extremity agility. They also exhibited an overall statistically significant improvement in quality of life scores after the exercise program. In terms of the main items, changes were observed in the areas of psychological relations, social relations, and environment. [Conclusion] The community-centered muscle strengthening exercise program using the elastic band was found to improve muscular endurance, balance, agility, and quality of life of rural elderly subjects. PMID:26311926

  19. Effects of electromyographic biofeedback on quadriceps strength: a systematic review.

    PubMed

    Lepley, Adam S; Gribble, Phillip A; Pietrosimone, Brian G

    2012-03-01

    Quadriceps strength is a vital component to lower extremity function and is often the focus in resistance training interventions and injury rehabilitation. Electromyographic biofeedback (EMGBF) is frequently used to supplement strength gains; however, the true effect remains unknown. Therefore, the objective of this investigation was to determine the magnitude of the treatment effect for EMGBF on quadriceps strength compared with that of placebo and traditional exercise interventions in both healthy and pathological populations. Web of Science and ProQuest databases were searched, and bibliographies of relevant articles were crossreferenced. Six articles measuring isometric quadriceps strength in response to EMGBF training were included and methodologically assessed using the Physiotherapy Evidence Database (PEDro). Standardized effect sizes with 95% confidence intervals (CIs) were calculated from preintervention and postintervention measures for EMGBF, placebo, and exercise-only interventions. Separate comparisons were made between studies assessing different intervention length (<4 and ≥4 weeks) and patient populations (pathological and healthy). Articles included received an average PEDro score of 6.5 ± 0.84. Homogeneous EMGBF effect sizes were found in all 6 studies (d = 0.01-5.56), with 4 studies reporting CI that crossed 0. A heterogeneous collection of effect sizes was found for exercise alone (d = -0.12 to 1.18) and placebo (d = -0.2 to 1.38), with 4 and 1 studies having a CI that crossed 0, respectively. The greatest EMGBF effects were found in pathological populations (d = 0.01-5.56), with the strongest effect found in the subjects with knee osteoarthritis (d = 5.56, CI = 4.26-6.68). As a group, effects were the strongest for EMGBF compared with that of placebo and exercise-only interventions, yet definitive evidence that EMGBF is beneficial for increasing quadriceps strength could not be concluded because of the 4 studies demonstrating a wide CI. PMID:22289696

  20. Effects of ankle strengthening exercises combined with motor imagery training on the timed up and go test score and weight bearing ratio in stroke patients

    PubMed Central

    Kim, Sung Shin; Lee, Hyung Jin; You, Young Youl

    2015-01-01

    [Purpose] The purpose of the present study was to compare the effects of ankle strengthening exercises combined with motor imagery training and those of ankle strengthening exercises alone in stroke patients. [Subjects and Methods] Thirty stroke patients were randomly assigned to one of the following two groups: experimental group (15 patients) and control group (15 patients). The experimental group underwent motor imagery training for 15 minutes and ankle joint strengthening exercises for 15 minutes, while the control group underwent only ankle joint strengthening exercises for 30 minutes. Each session and training program was implemented four times a week for 4 weeks. The timed up and go (TUG) test score, affected-side weight bearing ratio, and affected-side front/rear weight bearing ratio were assessed. [Results] Both groups demonstrated improvement on the TUG test, and in the affected-side weight bearing ratios, affected-side front/rear weight bearing ratios, and balance errors. The experimental group demonstrated greater improvement than the control group in all variables. [Conclusion] Motor imagery training is an effective treatment method for improving static balance ability in stroke patients. PMID:26311971

  1. Prevalence of quadriceps muscle weakness in patients with COPD and its association with disease severity

    PubMed Central

    Kharbanda, Sidharth; Ramakrishna, Anand; Krishnan, Shyam

    2015-01-01

    Introduction COPD presents with an array of extra-pulmonary symptoms of which skeletal muscle dysfunction, particularly of the quadriceps, is well recognized. This contributes to impaired quality of life and increased health care utilization. Work on the quadriceps originated from the observation that a good proportion of COPD patients stop exercise due to the feeling of leg fatigue rather than breathlessness. This study was carried out with the aim of finding the prevalence of quadriceps weakness in a population set and correlate it with severity of COPD. Methodology This cross-sectional study was conducted in 75 subjects suffering from COPD aged 45 years or above. COPD severity in the subjects was graded based on the GOLD staging system. A digital hand held dynamometer (HHD) was used to measure quadriceps muscle strength. Descriptive statistics were done, and Pearson’s Correlation Coefficient and ANOVA analysis was used for expressing the results. Results Ninety two percent of subjects were suffering from quadriceps muscle weakness. Quadriceps weakness was present in significantly high proportions even in those suffering from mild disease and belonging to a younger age group. The mean quadriceps muscle force value decreased with disease severity and this relation was found to be significant (P<0.01). Conclusion Majority of the COPD patients were found to be suffering from quadriceps weakness, which was also present in significant proportions in subjects belonging to younger age groups and suffering from mild disease. These findings indicate that onset of muscle weakness in COPD may precede the onset of symptoms. These findings suggest need for early remedial measure to prevent occurrence of associated systemic diseases. PMID:26366065

  2. Posture Exercises

    MedlinePLUS

    ... Search You are here Home » Posture Exercises Posture Exercises When a person develops kyphosis, the posture becomes ... and strengthen the back. Try the following two exercises to keep your spine more limber and flexible. ...

  3. Strengthening and stretching for rheumatoid arthritis of the hand (SARAH): design of a randomised controlled trial of a hand and upper limb exercise intervention - ISRCTN89936343

    PubMed Central

    2012-01-01

    Background Rheumatoid Arthritis (RA) commonly affects the hands and wrists with inflammation, deformity, pain, weakness and restricted mobility leading to reduced function. The effectiveness of exercise for RA hands is uncertain, although evidence from small scale studies is promising. The Strengthening And Stretching for Rheumatoid Arthritis of the Hand (SARAH) trial is a pragmatic, multi-centre randomised controlled trial evaluating the clinical and cost effectiveness of adding an optimised exercise programme for hands and upper limbs to best practice usual care for patients with RA. Methods/design 480 participants with problematic RA hands will be recruited through 17 NHS trusts. Treatments will be provided by physiotherapists and occupational therapists. Participants will be individually randomised to receive either best practice usual care (joint protection advice, general exercise advice, functional splinting and assistive devices) or best practice usual care supplemented with an individualised exercise programme of strengthening and stretching exercises. The study assessors will be blinded to treatment allocation and will follow participants up at four and 12 months. The primary outcome measure is the Hand function subscale of the Michigan Hand Outcome Questionnaire, and secondary outcomes include hand and wrist impairment measures, quality of life, and resource use. Economic and qualitative studies will also be carried out in parallel. Discussion This paper describes the design and development of a trial protocol of a complex intervention study based in therapy out-patient departments. The findings will provide evidence to support or refute the use of an optimised exercise programme for RA of the hand in addition to best practice usual care. Trial registration Current Controlled Trials ISRCTN89936343 PMID:23176133

  4. Effects of Stretching and Strengthening Exercises, With and Without Manual Therapy, on Scapular Kinematics, Function, and Pain in Individuals With Shoulder Impingement: A Randomized Controlled Trial.

    PubMed

    Camargo, Paula R; Alburquerque-Sendín, Francisco; Avila, Mariana A; Haik, Melina N; Vieira, Amilton; Salvini, Tania F

    2015-12-01

    Study Design Randomized controlled trial. Objective To evaluate the effects of an exercise protocol, with and without manual therapy, on scapular kinematics, function, pain, and mechanical sensitivity in individuals with shoulder impingement syndrome. Background Stretching and strengthening exercises have been shown to effectively decrease pain and disability in individuals with shoulder impingement syndrome. There is still conflicting evidence regarding the efficacy of adding manual therapy to an exercise therapy regimen. Methods Forty-six patients were assigned to 1 of 2 groups, one of which received a 4-week intervention of stretching and strengthening exercises (exercise alone) and the other the same intervention, supplemented by manual therapy targeting the shoulder and cervical spine (exercise plus manual therapy). All outcomes were measured preintervention and postintervention at 4 weeks. Outcome measures were scapular kinematics in the scapular and sagittal planes during arm elevation, function as determined through the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, pain as assessed with a visual analog scale, and mechanical sensitivity as assessed with pressure pain threshold. Results Independent of the intervention group, small, clinically irrelevant changes in scapular kinematics were observed postintervention. A significant group-by-time interaction effect (P = .001) was found for scapular anterior tilt during elevation in the sagittal plane, with a 3.0° increase (95% confidence interval [CI]: -1.5°, 7.5°) relative to baseline in the exercise-plus-manual therapy group compared to a decrease of 0.3° (95% CI: -4.2°, 4.8°) in the exercise-alone group. Pain, mechanical sensitivity, and the DASH score improved similarly for both groups by the end of the intervention period. Conclusion Adding manual therapy to an exercise protocol did not enhance improvements in scapular kinematics, function, and pain in individuals with shoulder impingement syndrome. The noted improvements in pain and function are not likely explained by changes in scapular kinematics. The study is registered at www.clinicaltrials.gov (NCT02035618). Level of Evidence Therapy, level 1b-. J Orthop Sports Phys Ther 2015;45(12):984-997. Epub 15 Oct 2015. doi:10.2519/jospt.2015.5939. PMID:26471852

  5. Influence of Resistance Exercise Training to Strengthen Muscles across Multiple Joints of the Lower Limbs on Dynamic Balance Functions of Stroke Patients.

    PubMed

    Son, Sung Min; Park, Myung Kyu; Lee, Na Kyung

    2014-08-01

    [Purpose] The objective of this study was to evaluate the effects of resistance exercise training for strengthening muscles across multiple joints on the dynamic balance function of stroke patients. [Subjects and Methods] Subjects in the training group (n=14) and the control group (n=14) received conservative physical therapy for 30 minutes per day, five days per week, for a period of six weeks. The training group additionally performed three sets (eight to 10 repetitions per set) of resistance exercise at 70% of the 1-repetition maximum (1RM) to strengthen muscles across multiple joints. The control group did the same exercises for the same duration but without resistance. To assess dynamic balance function, before and after the intervention, we measured antero-posterior (A-P) and medio-lateral (M-L) sway distances, the Berg balance scale (BBS), and the timed up and go (TUG) times. [Results] Compared to pre-intervention values, the BBS score showed significant increases in both groups, and A-P and M-L sway distances and TUG times showed significant decreases in both groups. Changes in A-P and M-L sway distances, BBS scores, and TUG times were significantly different between the muscle training group and the control group. [Conclusion] Training involving muscle strength across multiple joints is an effective intervention for improvement of dynamic balance function of stroke patients. PMID:25202193

  6. [New strategies for exercise training in osteoporosis].

    PubMed

    Winkelmann, A; Schilling, S; Neuerburg, C; Mutschler, W; Böcker, W; Felsenberg, D; Stumpf, U

    2015-11-01

    In the prevention and treatment of osteoporosis, movement with muscle strengthening and proprioceptive training plays a major role. This was taken into consideration in the guidelines by the governing body on osteoporosis (Dachverband Osteoporose, DVO) from 2014 on prophylaxis, diagnosis and treatment of osteoporosis and in the DVO guidelines from 2008 on physiotherapy and exercise therapy for osteoporosis. Increases in lumbar bone density of between 0.5 % and 2.5 % can be achieved in women by strengthening exercises with high resistance. With this combination and strengthening of the quadriceps muscle a reduction of falls and hence the fracture risk could also be achieved. In traumatology, training for muscle strengthening is not always possible, especially for elderly patients. Practically relevant alternatives are regular walking and aquatraining, which may also lead to a significant increase in bone mineral density. Furthermore, large effects can be achieved with alternating side whole-body vibration (WBV) training with whole body vibration plates with only 3 days of training per week and with short training periods (15-20 min). Rates of increase in leg strength between 20 % and almost 40 % and in bone density between 0.5 % and 4 % in 6 months have been described. Whether and with what intensity whole body vibration therapy could be used for e.g. more rapid healing of fractures, is currently unclear. Initial positive results have been described in animal models. PMID:26467265

  7. Minimally invasive quadriceps tendon harvest.

    PubMed

    Almazán Díaz, Arturo; Cruz López, Francisco; Pérez Jiménez, Francisco-Xavier; Ibarra Ponce de León, José-Clemente

    2006-06-01

    Quadriceps tendon (QT) is becoming a popular graft for primary and revision ligament surgery. A subcutaneous technique for graft harvesting a QT is presented. Special closed tendon strippers were designed; these devices have 10- and 11-mm inner diameters and are stronger and sharper than regular hamstrings strippers. In the mid-line of the patellar upper pole, a 2-cm longitudinal incision is made, a 20- x 10-mm bone plug is created with an oscillating saw, and the tendon stripper is positioned and advanced into the thigh, dissecting the QT until the desired length, usually 10 cm, is obtained. The graft can be released by making a stab incision at the device's tip or by ventrally pointing and turning the tendon stripper to amputate the graft's end. The QT graft can be prepared in several fashions for 1- or 2-bundle ligament reconstructions. The technique was tested and refined in 3 cadaver specimens and has been used at our institution since 2003 in 18 primary posterior cruciate ligament reconstructions with no problems. This minimally invasive technique is safe, provides a consistently good-quality graft with excellent cosmetic results, and is simple and easily reproducible. PMID:16762711

  8. Concentric and Eccentric Time-Under-Tension during Strengthening Exercises: Validity and Reliability of Stretch-Sensor Recordings from an Elastic Exercise-Band

    PubMed Central

    Skovdal Rathleff, Michael; Thorborg, Kristian; Bandholm, Thomas

    2013-01-01

    Background Total, single repetition and contraction-phase specific (concentric and eccentric) time-under-tension (TUT) are important exercise-descriptors, as they are linked to the physiological and clinical response in exercise and rehabilitation. Objective To investigate the validity and reliability of total, single repetition, and contraction-phase specific TUT during shoulder abduction exercises, based on data from a stretch-sensor attached to an elastic exercise band. Methods A concurrent validity and interrater reliability study with two raters was conducted. Twelve participants performed five sets of 10 repetitions of shoulder abduction exercises with an elastic exercise band. Exercises were video-recorded to assess concurrent validity between TUT from stretch-sensor data and from video recordings (gold standard). Agreement between methods was calculated using Limits of Agreement (LoA), and the association was assessed by Pearson correlation coefficients. Interrater reliability was calculated using intraclass correlation coefficients (ICC 2.1). Results Total, single repetition, and contraction-phase specific TUT – determined from video and stretch-sensor data – were highly correlated (r>0.99). Agreement between methods was high, as LoA ranged from 0.0 to 3.1 seconds for total TUT (2.6% of mean TUT), from -0.26 to 0.56 seconds for single repetition TUT (6.9%), and from -0.29 to 0.56 seconds for contraction-phase specific TUT (13.2-21.1%). Interrater reliability for total, single repetition and contraction-phase specific TUT was high (ICC>0.99). Interrater agreement was high, as LoA ranged from -2.11 to 2.56 seconds for total TUT (4.7%), from -0.46 to 0.50 seconds for single repetition TUT (9.7%) and from -0.41 to 0.44 seconds for contraction-phase specific TUT (5.2-14.5%). Conclusion Data from a stretch-sensor attached to an elastic exercise band is a valid measure of total and single repetition time-under-tension, and the procedure is highly reliable. This method will enable clinicians and researchers to objectively quantify if home-based exercises are performed as prescribed, with respect to time-under-tension. PMID:23825696

  9. Gait Biomechanics and Patient-Reported Function as Predictors of Response to a Hip Strengthening Exercise Intervention in Patients with Knee Osteoarthritis

    PubMed Central

    Kobsar, Dylan; Osis, Sean T.; Hettinga, Blayne A.; Ferber, Reed

    2015-01-01

    Objective Muscle strengthening exercises have been shown to improve pain and function in adults with mild-to-moderate knee osteoarthritis, but individual response rates can vary greatly. Predicting individuals who respond and those who do not is important in developing a more efficient and effective model of care for knee osteoarthritis (OA). Therefore, the purpose of this study was to use pre-intervention gait kinematics and patient-reported outcome measures to predict post-intervention response to a 6-week hip strengthening exercise intervention in patients with mild-to-moderate knee OA. Methods Thirty-nine patients with mild-to-moderate knee osteoarthritis completed a 6-week hip-strengthening program and were subgrouped as Non-Responders, Low-Responders, or High-Responders following the intervention based on their change in Knee injury Osteoarthritis Outcome Score (KOOS). Predictors of responder subgroups were retrospectively determined from baseline patient-reported outcome measures and kinematic gait parameters in a discriminant analysis of principal components. A 3–4 year follow-up on 16 of the patients with knee OA was also done to examine long-term changes in these parameters. Results A unique combination of patient-reported outcome measures and kinematic factors was able to successfully subgroup patients with knee osteoarthritis with a cross-validated classification accuracy of 85.4%. Lower patient-reported function in daily living (ADL) scores and hip frontal plane kinematics during the loading response were most important in classifying High-Responders from other sub-groups, while a combination of hip, knee, ankle kinematics were used to classify Non-Responders from Low-Responders. Conclusion Patient-reported outcome measures and objective biomechanical gait data can be an effective method of predicting individual treatment success to an exercise intervention. Measuring gait kinematics, along with patient-reported outcome measures in a clinical setting can be useful in helping make evidence-based decisions regarding optimal treatment for patients with knee OA. PMID:26444426

  10. Neuromuscular Adjustments of the Quadriceps Muscle after Repeated Cycling Sprints

    PubMed Central

    Girard, Olivier; Bishop, David J.; Racinais, Sébastien

    2013-01-01

    Purpose This study investigated the supraspinal processes of fatigue of the quadriceps muscle in response to repeated cycling sprints. Methods Twelve active individuals performed 10 × 6-s “all-out” sprints on a cycle ergometer (recovery  =  30 s), followed 6 min later by 5 × 6-s sprints (recovery  =  30 s). Transcranial magnetic and electrical femoral nerve stimulations during brief (5-s) and sustained (30-s) isometric contractions of the knee extensors were performed before and 3 min post-exercise. Results Maximal strength of the knee extensors decreased during brief and sustained contractions (∼11% and 9%, respectively; P<0.001). Peripheral and cortical voluntary activation, motor evoked potential amplitude and silent period duration responses measured during briefs contractions were unaltered (P>0.05). While cortical voluntary activation declined (P<0.01) during the sustained maximal contraction in both test sessions, larger reductions occurred (P<0.05) after exercise. Lastly, resting twitch amplitude in response to both femoral nerve and cortical stimulations was largely (> 40%) reduced (P<0.001) following exercise. Conclusion The capacity of the motor cortex to optimally drive the knee extensors following a repeated-sprint test was shown in sustained, but not brief, maximal isometric contractions. Additionally, peripheral factors were largely involved in the exercise-induced impairment in neuromuscular function, while corticospinal excitability was well-preserved. PMID:23650503

  11. Skeletal muscle alterations in chronic heart failure: differential effects on quadriceps and diaphragm

    PubMed Central

    Mangner, Norman; Weikert, Bettina; Bowen, T Scott; Sandri, Marcus; Höllriegel, Robert; Erbs, Sandra; Hambrecht, Rainer; Schuler, Gerhard; Linke, Axel; Gielen, Stephan; Adams, Volker

    2015-01-01

    Background Chronic heart failure (CHF) results in limb and respiratory muscle weakness, which contributes to exercise intolerance and increased morbidity and mortality, yet the molecular mechanisms remain poorly understood. Therefore, we aimed to compare parameters of antioxidative capacity, energy metabolism, and catabolic/anabolic balance in diaphragm and quadriceps muscle in an animal model of CHF. Methods Ligation of the left anterior descending coronary artery (n = 13) or sham operation (n = 11) was performed on Wistar Kyoto rats. After 12 weeks, echocardiography and invasive determination of maximal rates of left ventricular (LV) pressure change were performed. Antioxidative and metabolic enzyme activities and expression of catabolic/anabolic markers were assessed in quadriceps and diaphragm muscle. Results Ligated rats developed CHF (i.e. severe LV dilatation, reduced LV ejection fraction, and impaired maximal rates of LV pressure change; P < 0.001). There was a divergent response for antioxidant enzymes between the diaphragm and quadriceps in CHF rats, with glutathione peroxidase and manganese superoxide dismutase activity increased in the diaphragm but reduced in the quadriceps relative to shams (P < 0.01). Metabolic enzymes were unaltered in the diaphragm, but cytochrome c oxidase activity (P < 0.01) decreased and lactate dehydrogenase activity (P < 0.05) increased in the quadriceps of CHF animals. Protein expression of the E3 ligase muscle ring finger 1 and proteasome activity were increased (P < 0.05) in both the diaphragm and quadriceps in CHF rats compared with shams. Conclusion Chronic heart failure induced divergent antioxidative and metabolic but similar catabolic responses between the diaphragm and quadriceps. Despite the quadriceps demonstrating significant impairments in CHF, apparent beneficial adaptations of an increased antioxidative capacity were induced in the diaphragm. Nevertheless, muscle ring finger 1 and proteasome activity (markers of protein degradation) were elevated and oxidative enzyme activity failed to increase in the diaphragm of CHF rats, which suggest that a myopathy is likely present in respiratory muscle in CHF, despite its constant activation. PMID:26674018

  12. Intra- and intermuscular variation in human quadriceps femoris architecture assessed in vivo

    PubMed Central

    Blazevich, Anthony J; Gill, Nicholas D; Zhou, Shi

    2006-01-01

    Despite the functional importance of the human quadriceps femoris in movements such as running, jumping, lifting and climbing, and the known effects of muscle architecture on muscle function, no research has fully described the complex architecture of this muscle group. We used ultrasound imaging techniques to measure muscle thickness, fascicle angle and fascicle length at multiple regions of the four quadriceps muscles in vivo in 31 recreationally active, but non-strength-trained adult men and women. Our analyses revealed a reasonable similarity in the superficial quadriceps muscles, which is suggestive of functional similarity (at least during the uni-joint knee extension task) given that they act via a common tendon. The deep vastus intermedius (VI) is architecturally dissimilar and therefore probably serves a different function(s). Architecture varies significantly along the length of the superficial muscles, which has implications for the accuracy of models that assume a constant intramuscular architecture. It might also have consequences for the efficiency of intra- and intermuscular force transmission. Our results provide some evidence that subjects with a given architecture of one superficial muscle, relative to the rest of the subject sample, also have a similar architecture in other superficial muscles. However, this is not necessarily true for vastus lateralis (VL), and was not the case for VI. Therefore, the relative architecture of one muscle cannot confidently be used to estimate the relative architecture of another. To confirm this, we calculated a value of whole quadriceps architecture by four different methods. Regardless of the method used, we found that the absolute or relative architecture of one muscle could not be used as an indicator of whole quadriceps architecture, although vastus medialis, possibly in concert with VL and the anterior portion of VI, could be used to provide a useful snapshot. Importantly, our estimates of whole quadriceps architecture show a gender difference in whole quadriceps muscle thickness, and that muscle thickness is positively correlated with fascicle angle whereas fascicle length is negatively, although weakly, correlated with fascicle angle. These results are supportive of the validity of estimates of whole quadriceps architecture. These data are interpreted with respect to their implications for neural control strategies, region-specific adaptations in muscle size in response to training, and gender-dependent differences in the response to exercise training. PMID:16928199

  13. Exercises

    MedlinePLUS

    ... Sack, MS, PT Physical Therapist View full profile COPD: Lifestyle Management Exercise An exercise program is another very important step in managing COPD. It is common for people with lung disease ...

  14. Rapid recovery from spontaneous and simultaneous bilateral quadriceps tendon rupture in an active, healthy individual.

    PubMed

    Gaheer, Rajinder Singh; Hawkins, Amanda

    2010-07-01

    Bilateral spontaneous quadriceps rupture is an uncommon injury that is usually seen in association with multiple medical conditions and is frequently misdiagnosed. It is rarely seen in healthy, active individuals. This article presents a case of bilateral simultaneous and spontaneous rupture of the quadriceps tendon in a healthy, athletic, active and highly motivated patient with rapid recovery from injury and return to full sport activity within a relatively short period of time. A 65-year-old healthy man felt both knees give way while walking down stairs at home and collapsed, unable to bear weight. He was fit and well, not on any medications and basic laboratory screening was within normal limits. He was an active sportsman, horse rider, swimmer, and long-distance cyclist, and had completed a half marathon 1 month before his injury. He was diagnosed with bilateral quadriceps tendon ruptures. An ultrasound of both knees confirmed the diagnosis of full-thickness rupture. Surgical repair of both quadriceps tendons was performed 3 days after the injury. Bilateral locking brace in 10 degrees of flexion was used to immobilize both knees and protect the repair for 6 weeks. The patient remained nonweight bearing for 2 weeks, then gradual weight bearing was commenced, with full weight bearing at 6 weeks. Intensive isometric quadriceps exercises were started on the second postoperative day. Immobilization of both knees was maintained for 6 weeks, after which full active range of motion (ROM) was initiated. At 16 weeks after the injury he had bilateral ROM from 0 degrees to 120 degrees flexion, with no extension lag. He was horse riding, playing golf, swimming, and walking distances up to 2 miles at that time. PMID:20608622

  15. Intervention program in college instrumental musicians, with kinematics analysis of cello and flute playing: a combined program of yogic breathing and muscle strengthening-flexibility exercises.

    PubMed

    Lee, Sang-Hie; Carey, Stephanie; Dubey, Rajiv; Matz, Rachel

    2012-06-01

    College musicians encounter health risks not dissimilar to those of professional musicians. Fifteen collegiate instrumental musicians participated in the intervention program of yogic-breathing and muscle-strengthening and flexibility exercises for 8 weeks. Pre- and post-intervention data from the Health-Pain-Injury Inventory (HPI) and the Physical & Musical-Performance Efficacy Assessment Survey (PME) were analyzed for the effects of the program on the musicians' physical and musical-performance efficacy. HPI results showed that the majority of our sample had healthy lifestyles and minimal pain and injuries but irregular eating and exercise habits. The pre-intervention PME data showed a high level of musical efficacy (i.e., awareness of music technique, tone, and flow) but a low-level of physical efficacy (i.e., awareness of posture, tension, and movement flexibility). Post-intervention data showed that the program improved physical efficacy by increased awareness of posture and tension. In 2 volunteer musicians, kinematics motion analysis was conducted for exploratory purposes. Our cellist played the scale using a larger range of motion (ROM) in right shoulder flexion and abduction and slightly increased rotation while keeping decreased right elbow ROM after the intervention program. The flutist shifted the body weight from one foot to the other more in the second playing post-intervention. These changes can be attributed to the increased physical efficacy that allowed freedom to express musicality. Findings from these case scenarios provide empirically based hypotheses for further study. We share our experience so that others may use our model and instruments to develop studies with larger samples. PMID:22739821

  16. How to Strengthen Your Ankle After a Sprain

    MedlinePLUS

    ... a Sprain Page Content Following an ankle sprain, strengthening exercises should be performed once you can bear ... is near full. There are several types of strengthening exercises. The easiest to begin with are isometric ...

  17. Effects of exercise training in patients with idiopathic pulmonary arterial hypertension.

    PubMed

    de Man, F S; Handoko, M L; Groepenhoff, H; van 't Hul, A J; Abbink, J; Koppers, R J H; Grotjohan, H P; Twisk, J W R; Bogaard, H-J; Boonstra, A; Postmus, P E; Westerhof, N; van der Laarse, W J; Vonk-Noordegraaf, A

    2009-09-01

    We determined the physiological effects of exercise training on exercise capacity and quadriceps muscle function in patients with idiopathic pulmonary arterial hypertension (iPAH). In total, 19 clinically stable iPAH patients (New York Heart Association II-III) underwent a supervised exercise training programme for the duration of 12 weeks. Maximal capacity, endurance capacity and quadriceps function were assessed at baseline and after 12 weeks. In 12 patients, serial quadriceps muscle biopsies were obtained. 6-min walk distance and peak exercise capacity did not change after training. However, endurance capacity improved significantly after training, demonstrated by a shift of the anaerobic threshold to a higher workload (from 32+/-5 to 46+/-6 W; p = 0.003) together with an increase in exercise endurance time (p<0.001). Moreover, exercise training increased quadriceps strength by 13% (p = 0.005) and quadriceps endurance by 34% (p = 0.001). Training enhanced aerobic capacity of the quadriceps, by increasing capillarisation (1.36+/-0.10 to 1.78+/-0.13 capillaries per muscle fibre; p<0.001) and oxidative enzyme activity, especially of the type-I (slow) muscle fibres. No changes were found in cross-sectional area and fibre type distribution. Exercise training in iPAH improves exercise endurance and quadriceps muscle function, which is also reflected by structural changes of the quadriceps. PMID:19720810

  18. Exerciser

    NASA Technical Reports Server (NTRS)

    Lem, J. D.

    1977-01-01

    The Mark I exerciser which was added for the second and third Skylab missions, was used for a number of arm and leg exercises. This unit is a modified version of a commercial device. This is an iso-kinetic, or constant velocity, exerciser which retards the speed at which the user is allowed to move. The user applies a maximum effort and the device automatically varies the opposing resistance to maintain speed of translation at a constant preselected value.

  19. Quadriceps Tendon Rupture due to Postepileptic Convulsion

    PubMed Central

    Erkut, Adem; Guvercin, Yilmaz; Sahin, Rifat; Keskin, Davut

    2014-01-01

    We present a case of quadriceps tendon (QT) rupture. QT ruptures can occur in all ages. The cause is mostly traumatic in origin. Spontaneous ruptures that are thought to result from predisposing conditions are rare. Post-convulsion QT ruptures lacking traumas in their history can be overlooked in clinical examinations. This should be born in mind by the attending physician, as early diagnosis and treatment of the condition can lead to satisfactory outcomes. PMID:24944977

  20. Measurement of quadriceps endurance by fNIRS

    NASA Astrophysics Data System (ADS)

    Erdem, Devrim; Şayli, Ömer; Karahan, Mustafa; Akin, A.

    2006-02-01

    In this paper, the changes in muscle deoxygenation trends during a sustained isometric quadriceps (chair squat/half squat) endurance exercise were evaluated among twelve male subjects and the relationship between muscle oxygenation and endurance times was investigated by means of functional near-infrared spectroscopy (fNIRS). Neuromuscular activation and predictions of muscle performance decrements during extended fatiguing task was investigated by means of surface electromyography (sEMG). The results of the study showed that in the subjects who maintained exercise longer than five minutes (group 1), mean Hb recovery time (33 [sec.]) was 37.4% less than the others (group 2, 52.7 [sec.]). Also mean HbO II decline amplitude (2.53 [a.u.] in group 1 and 2.07 [a.u.] in group 2) and oxy decline amplitude (8.4 [a.u.] in group 1 and 3.04 [a.u.] in group 2) in the beginning of squat exercise are found to be 22.6% and 176.9% bigger in these group. For the EMG parameters, mean slope of MNF and MDF decline are found to be 57.5% and 42.2% bigger in magnitude in group 2 which indicates higher degree of decrement in mean and median frequencies although their mean squat duration time is less. This indicates higher index of fatigue for this group. It is concluded that training leads to altered oxygenation and oxygen extraction capability in the exercising muscle and investigated fNIRS parameters could be used for endurance evaluation.

  1. Quadriceps and Respiratory Muscle Fatigue Following High-Intensity Cycling in COPD Patients

    PubMed Central

    Bachasson, Damien; Wuyam, Bernard; Pepin, Jean-Louis; Tamisier, Renaud; Levy, Patrick; Verges, Samuel

    2013-01-01

    Exercise intolerance in COPD seems to combine abnormal ventilatory mechanics, impaired O2 transport and skeletal muscle dysfunction. However their relatie contribution and their influence on symptoms reported by patients remain to be clarified. In order to clarify the complex interaction between ventilatory and neuromuscular exercise limiting factors and symptoms, we evaluated respiratory muscles and quadriceps contractile fatigue, dynamic hyperinflation and symptoms induced by exhaustive high-intensity cycling in COPD patients. Fifteen gold II-III COPD patients (age = 67±6 yr; BMI = 26.6±4.2 kg.m-2) performed constant-load cycling test at 80% of their peak workload until exhaustion (9.3±2.4 min). Before exercise and at exhaustion, potentiated twitch quadriceps strength (Qtw), transdiaphragmatic (Pdi,tw) and gastric (Pga,tw) pressures were evoked by femoral nerve, cervical and thoracic magnetic stimulation, respectively. Changes in operational lung volumes during exercise were assessed via repetitive inspiratory capacity (IC) measurements. Dyspnoea and leg discomfort were measured on visual analog scale. At exhaustion, Qtw (-33±15%, >15% reduction observed in all patients but two) and Pdi,tw (-20±15%, >15% reduction in 6 patients) were significantly reduced (P<0.05) but not Pga,tw (-6±10%, >15% reduction in 3 patients). Percentage reduction in Qtw correlated with the percentage reduction in Pdi,tw (r=0.66; P<0.05). Percentage reductions in Pdi,tw and Pga,tw negatively correlated with the reduction in IC at exhaustion (r=-0.56 and r=-0.62, respectively; P<0.05). Neither dyspnea nor leg discomfort correlated with the amount of muscle fatigue. In conclusion, high-intensity exercise induces quadriceps, diaphragm and less frequently abdominal contractile fatigue in this group of COPD patients. In addition, the rise in end-expiratory lung volume and diaphragm flattening associated with dynamic hyperinflation in COPD might limit the development of abdominal and diaphragm muscle fatigue. This study underlines that both respiratory and quadriceps fatigue should be considered to understand the complex interplay of factors leading to exercise intolerance in COPD patients. PMID:24324843

  2. Simultaneous bilateral quadriceps tendon rupture while playing basketball.

    PubMed

    Shah, M; Jooma, N

    2002-04-01

    Simultaneous bilateral quadriceps tendon rupture is an uncommon injury in healthy people and only a few cases have been reported in athletes. This is the first report of a patient with simultaneous bilateral quadriceps tendon rupture incurred while playing basketball. The injury was surgically repaired and the patient had a good functional outcome. PMID:11916903

  3. Effects of feedback on activation of the quadriceps during weight-bearing tasks of the Wii.

    PubMed

    Fernandes da Silva, Fabiano; Aparecido de Souza, Renato; Dias, Eric Fernandes; Silveira, Landulfo; Villaverde, Antonio Balbin

    2015-06-01

    [Purpose] This investigation evaluated the effect of real-time feedback on electrical activation of the quadriceps during 3 weight-bearing tasks of the Wii Fit Plus(). [Subjects] Thirty male healthy volunteers were recruited. [Methods] Activation of the vastus medialis, vastus lateralis, and rectus femoris muscles was recorded during virtual lunge, single leg extension, and single leg reach exercises. Each exercise was performed twice in 3 randomized experimental conditions (with visual feedback, with auditory feedback, and with no feedback). The normalized electromyographic data (using maximum voluntary isometric contraction) were analyzed using repeated measures analysis of variance and Tukey's test. [Results] No significant difference was found in the muscles among the feedback conditions during the 3 exercises. However, the variation in the muscle activity of the vastus medialis and vastus lateralis (18.23-29.20% of maximum voluntary isometric contraction) was higher (47-62%) than that in the rectus femoris (7.35-12.98% of maximum voluntary isometric contraction). [Conclusion] Real-time feedback did not alter quadriceps activation during the Wii tasks. Additionally, these games showed electromyographic activation levels similar to those for the same tasks outside the virtual environment. The Wii weight-bearing tasks could therefore constitute a physical activity program but without the additional benefit of feedback. PMID:26180301

  4. Short-term creatine supplementation improves maximum quadriceps contraction in women.

    PubMed

    Kambis, Kenneth W; Pizzedaz, Sarah K

    2003-03-01

    Creatine monohydrate (CrH2O) supplementation has been demonstrated to increase skeletal muscle power output in men. However, its effect upon women is not as clearly defined. This study investigated the effect of oral creatine supplementation upon muscle function, thigh circumference, and body weight in women. Twenty-two consenting college-age women were assigned to 1 of 2 groups matched for dietary and exercise habits, phase of menstrual cycle, and fat-free mass (FFM). After familiarization with testing procedures, pretrial measures of muscle function (5 repetitions 60 deg x s(-1) and 50 repetitions 180 deg x s(-1) were conducted during maximal voluntary concentric contraction of the preferred quadriceps muscle using an isokinetic dynamometer. Subjects then ingested 0.5 g x kg(-1) FFM of either CrH2O or placebo (one fourth dosage 4 times daily) in a double-blind design for 5 days. Resistance exercise was prohibited. After the ingestion phase was completed, all measures were repeated at the same time of day as during pretrials. Statistical analysis revealed time to peak torque in quadriceps extension decreased from pre-test values of 255 +/- 11 ms (mean +/- SEM) to post-test values of 223 +/- 3 ms; average power in extension increased from 103 +/- 7 W pre-test to 112 +/- 7 W post-test; and, during flexion, average power increased from 59 +/- 5 W pre-test to 65 +/- 5 W post-test in the creatine group as compared to controls (p .05). FFM, percent body fat, mid-quadriceps circumference, skinfold thickness of the measured thigh, and total body weight did not change for both groups between trials. We conclude that CrH2O improves muscle performance in women without significant gains in muscle volume or body weight. PMID:12660408

  5. Wearable sensor-based rehabilitation exercise assessment for knee osteoarthritis.

    PubMed

    Chen, Kun-Hui; Chen, Po-Chao; Liu, Kai-Chun; Chan, Chia-Tai

    2015-01-01

    Since the knee joint bears the full weight load of the human body and the highest pressure loads while providing flexible movement, it is the body part most vulnerable and susceptible to osteoarthritis. In exercise therapy, the early rehabilitation stages last for approximately six weeks, during which the patient works with the physical therapist several times each week. The patient is afterwards given instructions for continuing rehabilitation exercise by him/herself at home. This study develops a rehabilitation exercise assessment mechanism using three wearable sensors mounted on the chest, thigh and shank of the working leg in order to enable the patients with knee osteoarthritis to manage their own rehabilitation progress. In this work, time-domain, frequency-domain features and angle information of the motion sensor signals are used to classify the exercise type and identify whether their postures are proper or not. Three types of rehabilitation exercise commonly prescribed to knee osteoarthritis patients are: Short-Arc Exercise, Straight Leg Raise, and Quadriceps Strengthening Mini-squats. After ten subjects performed the three kinds of rehabilitation activities, three validation techniques including 10-fold cross-validation, within subject cross validation, and leave-one-subject cross validation are utilized to confirm the proposed mechanism. The overall recognition accuracy for exercise type classification is 97.29% and for exercise posture identification it is 88.26%. The experimental results demonstrate the feasibility of the proposed mechanism which can help patients perform rehabilitation movements and progress effectively. Moreover, the proposed mechanism is able to detect multiple errors at once, fulfilling the requirements for rehabilitation assessment. PMID:25686308

  6. Wearable Sensor-Based Rehabilitation Exercise Assessment for Knee Osteoarthritis

    PubMed Central

    Chen, Kun-Hui; Chen, Po-Chao; Liu, Kai-Chun; Chan, Chia-Tai

    2015-01-01

    Since the knee joint bears the full weight load of the human body and the highest pressure loads while providing flexible movement, it is the body part most vulnerable and susceptible to osteoarthritis. In exercise therapy, the early rehabilitation stages last for approximately six weeks, during which the patient works with the physical therapist several times each week. The patient is afterwards given instructions for continuing rehabilitation exercise by him/herself at home. This study develops a rehabilitation exercise assessment mechanism using three wearable sensors mounted on the chest, thigh and shank of the working leg in order to enable the patients with knee osteoarthritis to manage their own rehabilitation progress. In this work, time-domain, frequency-domain features and angle information of the motion sensor signals are used to classify the exercise type and identify whether their postures are proper or not. Three types of rehabilitation exercise commonly prescribed to knee osteoarthritis patients are: Short-Arc Exercise, Straight Leg Raise, and Quadriceps Strengthening Mini-squats. After ten subjects performed the three kinds of rehabilitation activities, three validation techniques including 10-fold cross-validation, within subject cross validation, and leave-one-subject cross validation are utilized to confirm the proposed mechanism. The overall recognition accuracy for exercise type classification is 97.29% and for exercise posture identification it is 88.26%. The experimental results demonstrate the feasibility of the proposed mechanism which can help patients perform rehabilitation movements and progress effectively. Moreover, the proposed mechanism is able to detect multiple errors at once, fulfilling the requirements for rehabilitation assessment. PMID:25686308

  7. Estimation of the distribution of intramuscular current during electrical stimulation of the quadriceps muscle.

    PubMed

    Petrofsky, Jerrold; Prowse, Michelle; Bain, Melanie; Ebilane, Elaine; Suh, Hye Jin; Batt, Jennifer; Lawson, Daryl; Hernandez, Viviana; Abdo, Armia; Yang, Tien-Ning; Mendoza, Enrique; Collins, Kelly; Laymon, Michael

    2008-06-01

    Electrical stimulation is commonly used for strengthening muscle but little evidence exists as to the optimal electrode size, waveform, or frequency to apply. Three male and three female subjects (22-40 years old) were examined during electrical stimulation of the quadriceps muscle. Two self adhesive electrode sizes were examined, 2 cm x 2 cm and 2 cm x 4 cm. Electrical stimulation was applied with square and sine waveforms, currents of 5, 10 and 15 mA, and pulse widths of 100-500 micros above the quadriceps muscle. Frequencies of stimulation were 20, 30, and 50 Hz. Current on the skin above the quadriceps muscle was measured with surface electrodes at five positions and at three positions with needle electrodes in the same muscle. Altering pulse width in the range of 100-500 micros, the frequency over a range of 20-50 Hz, or current from 5 to 15 mA had no effect on current dispersion either in the skin or within muscle. In contrast, the distance separating the electrodes caused large changes in current dispersion on the skin or into muscle. The most significant finding in the present investigation was that, while on the surface of the skin current dispersion was not different between sine and square wave stimulation, significantly more current was transferred deep in the muscle with sine versus square wave stimulation. The use of sine wave stimulation with electrode separation distances of less then 15 cm is recommended for electrical stimulation with a sine wave to achieve deep muscle stimulation. PMID:18297301

  8. Self-regulatory skills usage strengthens the relations of self-efficacy for improved eating, exercise, and weight in the severely obese: toward an explanatory model.

    PubMed

    Annesi, James J

    2011-07-01

    Lack of success with behavioral weight-management treatments indicates a need for a better understanding of modifiable psychological correlates. Adults with class 2 and 3 obesity (N = 183; Mean(BMI) = 42.0 kg/m(2)) volunteered for a 26-week nutrition and exercise treatment, based on social cognitive theory, that focused on self-efficacy and self-regulation applied to increasing cardiovascular exercise and fruit and vegetable consumption. Improved self-efficacy for controlled eating significantly predicted increased fruit and vegetable consumption (R(2) = .15). Improved self-efficacy for exercise significantly predicted increased exercise (R(2) = .46). When changes in self-regulatory skill usage were stepped into the 2 previous equations, the variances accounted for significantly increased. Increases in fruit and vegetable consumption and exercise significantly predicted weight loss (R(2) = .38). Findings suggest that behavioral theory should guide research on weight-loss treatment, and a focus on self-efficacy and self-regulatory skills applied to specific nutrition and exercise behaviors is warranted. PMID:21895423

  9. Exercise-induced arterial hypoxemia: consequences for locomotor muscle fatigue.

    PubMed

    Romer, Lee M; Dempsey, Jerome A; Lovering, Andrew; Eldridge, Marlowe

    2006-01-01

    Reductions in arterial O2 saturation (-5 to -10% SaO2 < rest) occur over time during sustained heavy intensity exercise in a normoxic environment, due primarily to the effects of acid pH and increased temperature on the position of the HbO2 dissociation curve. We prevented the desaturation via increased F1O2 (.23 to .29) and showed that exercise time to exhaustion was increased. We used supramaximal magnetic stimulation (1 - 100 Hz) of the femoral nerve to test for quadriceps fatigue. We used mildly hyperoxic inspirates (F1O2 .23 to .29) to prevent O2 desaturation. We then compared the amount of quadriceps fatigue incurred following cycling exercise at SaO2 98% vs. 91% with each trial carried out at equal exercise intensities (90% Max) and for equal durations. Preventing the normal exercise-induced O2 desaturation prevented about one-half the amount of exercise-induced quadriceps fatigue; plasma lactate and effort perception were also reduced. We conclude that the normal exercise-induced O2 desaturation during heavy intensity endurance exercise contributes significantly to exercise performance limitation in part because of its effect on locomotor muscle fatigue. These effects of EIAH were confirmed in mild environmental hypoxia (FIO2 .17, SaO2 88%) which significantly augmented the magnitude of exercise-induced quadriceps fatigue observed in normoxia. PMID:17089878

  10. Patellofemoral Pain Syndrome

    MedlinePLUS

    ... t make sudden changes in your workouts. Quadriceps strengthening: Isometrics Lie flat on a firm surface, such ... Do the exercise 5 to 10 times. Quadriceps strengthening: Straight leg lift Lie flat on a firm ...

  11. Static vs. Dynamic Acute Stretching Effect on Quadriceps Muscle Activity during Soccer Instep Kicking.

    PubMed

    Amiri-Khorasani, Mohammadtaghi; Kellis, Eleftherios

    2013-12-18

    The purpose of this study was to compare the effects of static and dynamic stretching on quadriceps muscle activation during maximal soccer instep kicking. The kicking motion of twelve male college soccer players (body height: 174.66 ± 5.01 cm; body mass: 72.83 ± 4.83 kg; age: 18.83 ± 0.75 years) was captured using six synchronized high-speed infra-red cameras whilst electromyography (EMG) signals from vastus medialis (VM), lateralis (VL) and rectus femoris (RF) were recorded before and after static or dynamic stretching. Analysis of variance designs showed a higher increase in knee extension angular velocity (9.65% vs. -1.45%, p < 0.001), RF (37.5% vs. -8.33%, p < 0.001), VM (12% vs. -12%, p < 0.018), and VL EMG activity (20% vs. -6.67%, p < 0.001) after dynamic stretching exercises. Based on these results, it could be suggested that dynamic stretching is probably more effective in increasing quadriceps muscle activity and knee extension angular velocity during the final swing phase of a maximal soccer instep kick than static stretching. PMID:24511339

  12. Static vs. Dynamic Acute Stretching Effect on Quadriceps Muscle Activity during Soccer Instep Kicking

    PubMed Central

    Amiri-Khorasani, Mohammadtaghi; Kellis, Eleftherios

    2013-01-01

    The purpose of this study was to compare the effects of static and dynamic stretching on quadriceps muscle activation during maximal soccer instep kicking. The kicking motion of twelve male college soccer players (body height: 174.66 ± 5.01 cm; body mass: 72.83 ± 4.83 kg; age: 18.83 ± 0.75 years) was captured using six synchronized high-speed infra-red cameras whilst electromyography (EMG) signals from vastus medialis (VM), lateralis (VL) and rectus femoris (RF) were recorded before and after static or dynamic stretching. Analysis of variance designs showed a higher increase in knee extension angular velocity (9.65% vs. −1.45%, p < 0.001), RF (37.5% vs. −8.33%, p < 0.001), VM (12% vs. −12%, p < 0.018), and VL EMG activity (20% vs. −6.67%, p < 0.001) after dynamic stretching exercises. Based on these results, it could be suggested that dynamic stretching is probably more effective in increasing quadriceps muscle activity and knee extension angular velocity during the final swing phase of a maximal soccer instep kick than static stretching. PMID:24511339

  13. Muscle deoxygenation in the quadriceps during ramp incremental cycling: Deep vs. superficial heterogeneity.

    PubMed

    Okushima, Dai; Poole, David C; Rossiter, Harry B; Barstow, Thomas J; Kondo, Narihiko; Ohmae, Etsuko; Koga, Shunsaku

    2015-12-01

    Muscle deoxygenation (i.e., deoxy[Hb + Mb]) during exercise assesses the matching of oxygen delivery (Q̇O2) to oxygen utilization (V̇O2). Until now limitations in near-infrared spectroscopy (NIRS) technology did not permit discrimination of deoxy[Hb + Mb] between superficial and deep muscles. In humans, the deep quadriceps is more highly vascularized and oxidative than the superficial quadriceps. Using high-power time-resolved NIRS, we tested the hypothesis that deoxygenation of the deep quadriceps would be less than in superficial muscle during incremental cycling exercise in eight males. Pulmonary V̇O2 was measured and muscle deoxy[Hb + Mb] was determined in the superficial vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF-s) and the deep rectus femoris (RF-d). deoxy[Hb + Mb] in RF-d was significantly less than VL at 70% (67.2 ± 7.0 vs. 75.5 ± 10.7 μM) and 80% (71.4 ± 11.0 vs. 79.0 ± 15.4 μM) of peak work rate (WR(peak)), but greater than VL and VM at WR(peak) (87.7 ± 32.5 vs. 76.6 ± 17.5 and 75.1 ± 19.9 μM). RF-s was intermediate at WR(peak) (82.6 ± 18.7 μM). Total hemoglobin and myoglobin concentration and tissue oxygen saturation were significantly greater in RF-d than RF-s throughout exercise. The slope of deoxy[Hb + Mb] increase (proportional to Q̇O2/V̇O2) in VL and VM slowed markedly above 70% WR(peak), whereas it became greater in RF-d. This divergent deoxygenation pattern may be due to a greater population of slow-twitch muscle fibers in the RF-d muscle and the differential recruitment profiles and vascular and metabolic control properties of specific fiber populations within superficial and deeper muscle regions. PMID:26404619

  14. Acute effects of static stretching on peak and end-range hamstring-to-quadriceps functional ratios

    PubMed Central

    Sekir, Ufuk; Arabaci, Ramiz; Akova, Bedrettin

    2015-01-01

    AIM: To evaluate if static stretching influences peak and end-range functional hamstring-to-quadriceps (H/Q) strength ratios in elite women athletes. METHODS: Eleven healthy female athletes in an elite competitive level participated to the study. All the participants fulfilled the static stretching or non-stretching (control) intervention protocol in a randomized design on different days. Two static unassisted stretching exercises, one in standing and one in sitting position, were used to stretch both the hamstring and quadriceps muscles during these protocols. The total time for the static stretching was 6 ± 1 min. The isokinetic peak torque measurements for the hamstring and quadriceps muscles in eccentric and concentric modes and the calculations for the functional H/Q strength ratios at angular velocities of 60°/s and 180°/s were made before (pre) and after (post) the control or stretching intervention. The strength measurements and functional strength ratio calculations were based during the entire- and end-range of knee extension. RESULTS: The pre-test scores for quadriceps and hamstring peak torque and end range values were not significantly different between the groups (P > 0.05). Subsequently, although the control group did not exhibit significant changes in quadriceps and hamstring muscle strength (P > 0.05), static stretching decreased eccentric and concentric quadriceps muscle strength at both the 60°/s and 180°/s test speeds (P < 0.01). Similarly, static stretching also decreased eccentric and concentric hamstring muscle strength at both the 60°/s and 180°/s test speeds (P < 0.01). On the other hand, when the functional H/Q strength ratios were taken into consideration, the pre-intervention values were not significant different between the groups both during the entire and end range of knee extension (P > 0.05). Furthermore, the functional H/Q strength ratios exhibited no significant alterations during the entire and end ranges of knee extension both in the static stretching or the control intervention (P > 0.05). CONCLUSION: According to our results, static stretching routine does not influence functional H/Q ratio. Athletes can confidently perform static stretching during their warm-up routines. PMID:26495249

  15. Effects of Kinesio Tape application to quadriceps muscles on isokinetic muscle strength, gait, and functional parameters in patients with stroke.

    PubMed

    Ekiz, Timur; Aslan, Meryem Doğan; Özgirgin, Neşe

    2015-01-01

    The aim of this study was to evaluate the effects of Kinesio Tape (KT) application to quadriceps muscles on isokinetic muscle strength, gait, and functional parameters in patients with stroke. Twenty-four patients were allocated into KT and control groups. All patients participated in the same conventional rehabilitation program 5 times/wk for 4 wk. In addition, KT was applied to quadriceps muscles bilaterally to the patients in the KT group. Compared with baseline, peak torque levels increased significantly in both groups (all p < 0.05). However, change levels were significantly higher in the KT group than the control group at 60 degrees/second angular velocity (AV) in extension (p = 0.04) and 60 and 180 degrees/second AV in flexion (both p = 0.02) on the paretic side. Moreover, the change levels were more prominent in the KT group at 60 and 180 degrees/second AV in extension (p = 0.03 and p = 0.04, respectively) on the nonparetic side. Gait, balance, mobility, and quality of life values improved significantly in both groups (all p < 0.05), yet the change levels between the groups did not reach significance (p > 0.05). KT application to quadriceps muscles in addition to conventional exercises for 4 wk is effective on isokinetic but not functional parameters. PMID:26220179

  16. Optimal stimulation parameters to detect deficits in quadriceps voluntary activation.

    PubMed

    Grindstaff, Terry L; Threlkeld, A Joseph

    2014-02-01

    The purpose of this study was to determine optimal stimulation parameters and calculation methods to estimate quadriceps voluntary activation while minimizing participant discomfort. Twelve healthy adults (8 men and 4 women; mean ± SD, age = 36.8 ± 15.6 years, weight = 76.1 ± 12.9 kg, height = 170.2 ± 8.6 cm). Repeated maximal volitional isometric contractions (MVIC) were performed while imposing 4 stimulation combinations (10 or 2 pulses; 400 or 200 V; and variable or standardized current) with the quadriceps in a relaxed state (resting twitch [RT]) and during an MVIC. Quadriceps activation was quantified by calculating the central activation ratio and the percent activation. Discomfort was quantified using the visual analog scale. When comparing calculation methods between the same stimulation parameters, the central activation ratio calculation method produced quadriceps activation values that were significantly greater (p < 0.009) than those derived using the percent activation calculation method. The doublet pulse stimulus produced less discomfort during the RT (p < 0.04) and MVIC (p < 0.001) when compared with all other combinations using a train of stimuli (10 pulses). Correlations for all estimates of quadriceps activation were strong (r = 0.85-0.99, p < 0.001). A doublet pulse stimulus produced discomfort levels that were over 50% lower than a 10-pulse train of stimuli and correlated well (r > 0.88) with activation levels obtained with a 10-pulse train of stimuli. Therefore, the use of a doublet pulse stimulus provides quadriceps activation information equivalent to other methods while minimizing participant discomfort. PMID:23669820

  17. Opposite effects of hyperoxia on mitochondrial and contractile efficiency in human quadriceps muscles.

    PubMed

    Layec, Gwenael; Bringard, Aurélien; Le Fur, Yann; Micallef, Jean-Paul; Vilmen, Christophe; Perrey, Stéphane; Cozzone, Patrick J; Bendahan, David

    2015-04-15

    Exercise efficiency is an important determinant of exercise capacity. However, little is known about the physiological factors that can modulate muscle efficiency during exercise. We examined whether improved O2 availability would 1) impair mitochondrial efficiency and shift the energy production toward aerobic ATP synthesis and 2) reduce the ATP cost of dynamic contraction owing to an improved neuromuscular efficiency, such that 3) whole body O2 cost would remain unchanged. We used (31)P-magnetic resonance spectroscopy, surface electromyography, and pulmonary O2 consumption (V̇o2p) measurements in eight active subjects during 6 min of dynamic knee-extension exercise under different fractions of inspired O2 (FiO2 , 0.21 in normoxia and 1.0 in hyperoxia). V̇o2p (755 ± 111 ml/min in normoxia and 799 ± 188 ml/min in hyperoxia, P > 0.05) and O2 cost (P > 0.05) were not significantly different between normoxia and hyperoxia. In contrast, the total ATP synthesis rate and the ATP cost of dynamic contraction were significantly lower in hyperoxia than normoxia (P < 0.05). As a result, the ratio of the rate of oxidative ATP synthesis from the quadriceps to V̇o2p was lower in hyperoxia than normoxia but did not reach statistical significance (16 ± 3 mM/ml in normoxia and 12 ± 5 mM/ml in hyperoxia, P = 0.07). Together, these findings reveal dynamic and independent regulations of mitochondrial and contractile efficiency as a consequence of O2 availability in young active individuals. Furthermore, muscle efficiency appears to be already optimized in normoxia and is unlikely to contribute to the well-established improvement in exercise capacity induced by hyperoxia. PMID:25695290

  18. Diminished sub-maximal quadriceps force control in anterior cruciate ligament reconstructed patients is related to quadriceps and hamstring muscle dyskinesia.

    PubMed

    Telianidis, Stacey; Perraton, Luke; Clark, Ross A; Pua, Yong-Hao; Fortin, Karine; Bryant, Adam L

    2014-08-01

    The aim of this study was to determine the effects of anterior cruciate ligament reconstruction (ACLR) on sub-maximal quadriceps force control with respect to quadriceps and hamstring muscle activity. Thirty ACLR individuals together with 30 healthy individuals participated. With real-time visual feedback of muscle force output and electromyographic electrodes attached to the quadriceps and hamstring muscles, subjects performed an isometric knee extension task where they increased and decreased their muscle force output at 0.128Hz within a range of 5-30% maximum voluntary capacity. The ACLR group completed the task with more error and increased medial hamstring and vastus medialis activation (p<0.05). Moderate negative correlations (p<0.05) were observed between quadriceps force control and medial (Spearman's rho=-0.448, p=0.022) and lateral (Spearman's rho=-0.401, p=0.034) hamstring activation in the ACLR group. Diminished quadriceps sub-maximal force control in ACLR subjects was reflective of medial quadriceps and hamstring dyskinesia (i.e., altered muscle activity patterns and coordination deficits). Within the ACLR group however, augmented hamstring co-activation was associated with better quadriceps force control. Future studies should explore the convergent validity of quadriceps force control in ACLR patients. PMID:24875460

  19. Fatigue and rapid hamstring/quadriceps force capacity in professional soccer players.

    PubMed

    Greco, Camila C; da Silva, Wendell L; Camarda, Sérgio R A; Denadai, Benedito S

    2013-01-01

    The aim of this study was to investigate the effect of fatigue induced by an exhaustive laboratory-based soccer-specific exercise on different hamstrings/quadriceps (H:Q) ratios of soccer players. Twenty-two male professional soccer players (23·1 ± 3·4 year) performed maximal eccentric (ecc) and concentric (con) contractions for knee extensors (KE) and flexors (KF) at 60° s(-1) and 180° s(-1) to assess conventional (H(con) :Q(con)) and functional (H(ecc) :Q(con)) ratios. Additionally, they performed maximal voluntary isometric contraction for KE and KF, from which the maximal muscle strength, rate of force development (RFD) and RFD H:Q strength ratio (RFDH:Q) were extracted. Thereafter, subjects were performed an exhaustive laboratory-based soccer-specific exercise and a posttest similar to the pretest. There was significant reduction in H(con) :Q(con) (0·60 ± 0·06 versus 0·58 ± 0·06, P<0·05) and in H(ecc) :Q(con) (1·29 ± 0·2 versus 1·16 ± 0·2, P<0·01) after the soccer-specific exercise. However, no significant difference between Pre and Post exercise conditions was found for RFDH:Q at 0-50 (0·53 ± 0·23 versus 0·57 ± 0·24, P>0·05) and 0-100 ms (0·53 ± 0·17 versus 0·55 ± 0·17, P>0·05). In conclusion, H:Q strength ratios based on peak force values are more affected by fatigue than RFDH:Q obtained during early contraction phase. Thus, fatigue induced by soccer-specific intermittent protocol seems not reduce the potential for knee joint stabilization during the initial phase of voluntary muscle contraction. PMID:23216761

  20. Effects of Open and Closed Kinetic Chains of Sling Exercise Therapy on the Muscle Activity of the Vastus Medialis Oblique and Vastus Lateralis

    PubMed Central

    Chang, Wen-Dien; Huang, Wei-Syuan; Lee, Chia-Lun; Lin, Hung-Yu; Lai, Ping-Tung

    2014-01-01

    [Purpose] The muscle strength of the quadriceps muscle is critical in patellofemoral pain syndrome. The quadriceps muscle supplies the power for dynamic patellar movement, and the vastus medialis oblique (VMO) and vastus lateralis (VL) enable the patella to stabilize during tracking. We followed the theories about open and closed kinetic chain exercises to design two exercises, sling open chain knee extension (SOCKE) exercise and sling closed chain knee extension (SCCKE) exercise. The purpose of our study was to research the changes in quadriceps muscle activity during both exercises. [Methods] Electromyographic analysis was used to explore the different effects of the two exercises. The MVC% was calculated for the VMO and VL during exercise for analysis. [Results] We found that the mean MVC% values of the VMO and VL during the SOCKE exercise were higher than those during the SCCKE exercise. The ratio of the VMO to VL was 1.0 ± 0.19 during the SOCKE exercise and 1.11 ± 0.15 during the SCCKE exercise. [Conclusions] The SOCKE exercise is targeted at quadriceps muscle training and has a recruitment effect on the VMO. The beneficial effect of the SOCKE exercise is better than that of the SCCKE exercise. PMID:25276016

  1. The Effects of Closed Kinetic Chain Exercises and Open Kinetic Chain Exercises Using Elastic Bands on Electromyographic Activity in Degenerative Gonarthritis

    PubMed Central

    Cho, Igsoo; Hwangbo, Gak; Lee, Daehee; Lee, Sangyong

    2014-01-01

    [Purpose] The purpose of this study was to examine the effects of closed kinetic chain exercises (CKCEs) and open kinetic chain exercises (OKCEs) with elastic bands on the electromyographic activity of patients with degenerative gonarthritis. [Subjects] The study subjects were 30 degenerative gonarthritis patients who were divided into a CKCE group (CKCEG, n=10), an OKCE group (OKCEG, n=10), and a control group (CG, n=10). [Methods] The CKCEG and the OKCEG performed exercises with elastic bands, and the CG took part in a quadriceps strengthening exercise. All three groups performed the exercises three times per week for four weeks. The electromyographic activities of the subjects’ vastus medialis (VM), rectus femoris (RF), vastus lateralis (VL), semitendinosus (ST), and biceps femoris (BF) muscles were measured and compared. [Results] Within-group comparisons revealed that the electromyographic activities of the VM, RF, VL, ST, and BF muscles increased significantly in the CKCEG. The OKCEG displayed significant increases in the electromyographic activity of the VM, RF, ST, and BF muscles, and the CG showed significant increases in the electromyographic activities of the RF, VL, ST, and BF muscles. In between-group comparisons after the intervention, the electromyographic activities of the VM, RF, and VL muscles of the CKCEG were significantly higher than those of the CG. The electromyographic activities of the VM, RF, and ST muscles of the OKCEG were significantly higher than those of the CG. [Conclusion] We consider CKCEs with elastic bands are an effective intervention for increasing the electromyographic activities of the VM, RF, VL, ST, and BF muscles of degenerative gonarthritis patients, and OKCEs with elastic bands are an effective intervention for increasing the electromyographic activities of the VM, RF, ST, and BF muscles of degenerative gonarthritis patients. PMID:25276041

  2. Examining the Association Between Quadriceps Strength and Cognitive Performance in the Elderly

    PubMed Central

    Chen, Wei-Liang; Peng, Tao-Chun; Sun, Yu-Shan; Yang, Hui-Fang; Liaw, Fang-Yih; Wu, Li-Wei; Chang, Yaw-Wen; Kao, Tung-Wei

    2015-01-01

    Abstract Emerging evidences showed impaired muscle strength was prevalent in older adults with mild cognition impairment or dementia. However, little was known about the role of quadriceps strength in the cognition decline among older population. The objective of our study was to investigate the relation between quadriceps strength and cognitive performance. Using data from the National Health and Nutrition Examination Survey (1999–2002), a total of 1799 participants aged ≥60 years were enrolled in the study. Every subject completed a household interview, digit symbol substitution test (DSST), physical performances, and a questionnaire regarding personal health. Estimation of relationship between quadriceps strength and cognition was using multiple linear regression and quartile-based analysis with an extended-model approach for covariates adjustment. In a model adjusted for demographics, chronic diseases, health behaviors, and levels of folate and vitamin B12, the level of quadriceps strength was significantly associated with the scores of DSST. The β coefficient interpreted as change of DSST scores for each Newton increment in quadriceps strength comparing participants in the highest quartile of quadriceps strength to those in the lowest quartile was 5.003 (95% confidence interval, 2.725–7.281, P < 0.001). The trends of incremental DSST score across increasing quartiles of quadriceps strength were statistically significant (all P for trend <0.001). Higher quadriceps strength was associated with better cognitive performance. PMID:26266380

  3. Creatine Loading, Resistance Exercise Performance, and Muscle Mechanics.

    ERIC Educational Resources Information Center

    Stevenson, Scott W.; Dudley, Gary A.

    2001-01-01

    Examined whether creatine (CR) monohydrate loading would alter resistance exercise performance, isometric strength, or in vivo contractile properties of the quadriceps femoris muscle compared with placebo loading in resistance-trained athletes. Overall, CR loading did not provide an ergogenic benefit for the unilateral dynamic knee extension

  4. Creatine Loading, Resistance Exercise Performance, and Muscle Mechanics.

    ERIC Educational Resources Information Center

    Stevenson, Scott W.; Dudley, Gary A.

    2001-01-01

    Examined whether creatine (CR) monohydrate loading would alter resistance exercise performance, isometric strength, or in vivo contractile properties of the quadriceps femoris muscle compared with placebo loading in resistance-trained athletes. Overall, CR loading did not provide an ergogenic benefit for the unilateral dynamic knee extension…

  5. Expiratory muscle loading increases intercostal muscle blood flow during leg exercise in healthy humans

    PubMed Central

    Athanasopoulos, Dimitris; Louvaris, Zafeiris; Cherouveim, Evgenia; Andrianopoulos, Vasilis; Roussos, Charis; Zakynthinos, Spyros

    2010-01-01

    We investigated whether expiratory muscle loading induced by the application of expiratory flow limitation (EFL) during exercise in healthy subjects causes a reduction in quadriceps muscle blood flow in favor of the blood flow to the intercostal muscles. We hypothesized that, during exercise with EFL quadriceps muscle blood flow would be reduced, whereas intercostal muscle blood flow would be increased compared with exercise without EFL. We initially performed an incremental exercise test on eight healthy male subjects with a Starling resistor in the expiratory line limiting expiratory flow to ∼ 1 l/s to determine peak EFL exercise workload. On a different day, two constant-load exercise trials were performed in a balanced ordering sequence, during which subjects exercised with or without EFL at peak EFL exercise workload for 6 min. Intercostal (probe over the 7th intercostal space) and vastus lateralis muscle blood flow index (BFI) was calculated by near-infrared spectroscopy using indocyanine green, whereas cardiac output (CO) was measured by an impedance cardiography technique. At exercise termination, CO and stroke volume were not significantly different during exercise, with or without EFL (CO: 16.5 vs. 15.2 l/min, stroke volume: 104 vs. 107 ml/beat). Quadriceps muscle BFI during exercise with EFL (5.4 nM/s) was significantly (P = 0.043) lower compared with exercise without EFL (7.6 nM/s), whereas intercostal muscle BFI during exercise with EFL (3.5 nM/s) was significantly (P = 0.021) greater compared with that recorded during control exercise (0.4 nM/s). In conclusion, increased respiratory muscle loading during exercise in healthy humans causes an increase in blood flow to the intercostal muscles and a concomitant decrease in quadriceps muscle blood flow. PMID:20507965

  6. Is Single-Radius Design Better for Quadriceps Recovery in Total Knee Arthroplasty?

    PubMed Central

    Kim, Duk-Hyun; Kim, Dong-Kyoon; Lee, Sang-Hak; Bae, Dae-Kyung

    2015-01-01

    Purpose Although single-radius (SR) designs have a theoretical advantage in quadriceps recovery following total knee arthroplasty (TKA), there has been a paucity of objective evaluation studies. Materials and Methods One hundred and twenty minimally invasive TKAs were prospectively randomized by a single surgeon into 2 groups: SR design TKA group and multi-radius design TKA group. Quadriceps force and power were assessed using a dynamometer, and clinical data were investigated preoperatively and 6 weeks, 3 months, 6 months and 1 year postoperatively. Results There were no differences between two groups in quadriceps recovery and clinical results throughout the follow-up period. Furthermore, the proportion of patients whose postoperative quadriceps force and power reached preoperative level was similar in both groups. Conclusions Femoral component design itself would not significantly influence quadriceps recovery after TKA. PMID:26676282

  7. Quadriceps muscle injury in trans-femoral amputees.

    PubMed

    Alsindi, Z; Datta, D

    1998-12-01

    Two male trans-femoral amputees using modular trans-femoral prostheses lost control and fell to the ground when their prosthetic knees gave way. The semi-automatic knee lock malfunctioned in the first case while the free knee stabilising mechanics gave way in the second case. This resulted in a high tensile force acting on the contralateral quadriceps muscle causing it to rupture. As there are a significant number of patients with both kinds of prostheses it is important to be aware of this possibility so that necessary actions can be taken to minimise its occurrence. Even with the currently available weight activated stance phase control, the prosthetic knee will give way if the knee is flexed more than 20 degrees on weight bearing. Good power and control of hip extensors on the amputation side is needed to control the prosthetic knee joint, especially in the early stage of the walking cycle, i.e., from heel strike to mid-stance. Quadriceps muscle injury in amputees, as far as the authors are aware, has not been reported previously. PMID:9881613

  8. Immediate Effects of Kinesiology Taping of Quadriceps on Motor Performance after Muscle Fatigued Induction.

    PubMed

    Ahn, Ick Keun; Kim, You Lim; Bae, Young-Hyeon; Lee, Suk Min

    2015-01-01

    Objectives. The purpose of this cross-sectional single-blind study was to investigate the immediate effects of Kinesiology taping of quadriceps on motor performance after muscle fatigued induction. Design. Randomized controlled cross-sectional design. Subjects. Forty-five subjects participated in this study. Participants were divided into three groups: Kinesiology taping group, placebo taping group, and nontaping group. Methods. Subjects performed short-term exercise for muscle fatigued induction, followed by the application of each intervention. Peak torque test, one-leg single hop test, active joint position sense test, and one-leg static balance test were carried out before and after the intervention. Results. Peak torque and single-leg hopping distance were significantly increased when Kinesiology taping was applied (p < 0.05). But there were no significant effects on active joint position sense and single-leg static balance. Conclusions. We proved that Kinesiology taping is effective in restoring muscle power reduced after muscle fatigued induction. Therefore, we suggest that Kinesiology taping is beneficial for fatigued muscles. PMID:26246835

  9. Immediate Effects of Kinesiology Taping of Quadriceps on Motor Performance after Muscle Fatigued Induction

    PubMed Central

    Ahn, Ick Keun; Kim, You Lim; Bae, Young-Hyeon; Lee, Suk Min

    2015-01-01

    Objectives. The purpose of this cross-sectional single-blind study was to investigate the immediate effects of Kinesiology taping of quadriceps on motor performance after muscle fatigued induction. Design. Randomized controlled cross-sectional design. Subjects. Forty-five subjects participated in this study. Participants were divided into three groups: Kinesiology taping group, placebo taping group, and nontaping group. Methods. Subjects performed short-term exercise for muscle fatigued induction, followed by the application of each intervention. Peak torque test, one-leg single hop test, active joint position sense test, and one-leg static balance test were carried out before and after the intervention. Results. Peak torque and single-leg hopping distance were significantly increased when Kinesiology taping was applied (p < 0.05). But there were no significant effects on active joint position sense and single-leg static balance. Conclusions. We proved that Kinesiology taping is effective in restoring muscle power reduced after muscle fatigued induction. Therefore, we suggest that Kinesiology taping is beneficial for fatigued muscles. PMID:26246835

  10. The effects of squatting with visual feedback on the muscle activation of the vastus medialis oblique and the vastus lateralis in young adults with an increased quadriceps angle

    PubMed Central

    Hwangbo, Pil-Neo

    2015-01-01

    [Purpose] The purpose of this study was to identify the effects of performing squat exercises with visual feedback on the activation of the vastus medialis oblique (VMO) and vastus lateralis (VL) muscles in young adults with an increased quadriceps angle (Q-angle). [Subjects] This study used a motion analysis program (Dartfish, Switzerland) to select 20 young adults with an increased Q-angle, who were then divided into a squat group that received visual feedback (VSG, n=10) and a squat group that received no visual feedback (SG, n=10). [Methods] The intensity of exercises was increased every two weeks over a six-week exercise period in both groups. A visual marker was attached to the patella of the subjects in the VSG, and they then performed squat exercises with a maximum of 90° of knee flexion within a route marked on a mirror. The SG performed squat exercises with a maximum 90° of knee flexion without attaching a visual feedback device. [Results] Analysis of the muscle activation due to 90° squat exercises indicated that both groups had statistically significant increases in activation of the VL. The VSG exhibited statistically significant increases in activation of the VMO. [Conclusion] This study confirmed that squat exercises with visual feedback are effective in activation of the VMO and VL muscles. The findings are meaningful in terms of preventing the occurrence of patellofemoral pain. PMID:26157251

  11. Quadriceps intramuscular fat fraction rather than muscle size is associated with knee osteoarthritis

    PubMed Central

    Kumar, Deepak; Karampinos, Dimitrios C.; MacLeod, Toran D.; Lin, Wilson; Nardo, Lorenzo; Li, Xiaojuan; Link, Thomas M; Majumdar, Sharmila; Souza, Richard B

    2014-01-01

    Objectives To compare thigh muscle intramuscular fat (intraMF) fractions and area between people with and without knee radiographic osteoarthritis (ROA); and to evaluate the relationships of quadriceps adiposity and area with strength, function and knee MRI lesions. Methods Ninety six subjects (ROA: KL >1; n = 30, control: KL = 0,1; n = 66) underwent 3-Tesla MRI of the thigh muscles using chemical shift-based water/fat MR imaging (fat fractions) and the knee (clinical grading). Subjects were assessed for isometric/isokinetic quadriceps/hamstrings strength, function (KOOS, stair climbing test [SCT], and 6-minute walk test [(6MWT]. Thigh muscle intraMF fractions, muscle area and strength, and function were compared between controls and ROA subjects, adjusting for age. Relationships between measures of muscle fat/area with strength, function, KL and lesion scores were assessed using regression and correlational analyses. Results The ROA group had worse KOOS scores but SCT and 6MWT were not different. The ROA group had greater quadriceps intraMF fraction but not for other muscles. Quadriceps strength was lower in ROA group but the area was not different. Quadriceps intraMF fraction but not area predicted self-reported disability. Aging, worse KL, and cartilage and meniscus lesions were associated with higher quadriceps intraMF fraction. Conclusion Quadriceps intraMF is higher in people with knee OA and is related to symptomatic and structural severity of knee OA, where as the quadriceps area is not. Quadriceps fat fraction from chemical shift-based water/fat MR imaging may have utility as a marker of structural and symptomatic severity of knee OA disease process. PMID:24361743

  12. Persistent Neuromuscular and Corticomotor Quadriceps Asymmetry After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Kuenze, Christopher M.; Hertel, Jay; Weltman, Arthur; Diduch, David; Saliba, Susan A.; Hart, Joseph M.

    2015-01-01

    Context: Return to activity in the presence of quadriceps dysfunction may predispose individuals with anterior cruciate ligament reconstruction (ACLR) to long-term joint degeneration. Asymmetry may manifest during movement and result in altered knee-joint–loading patterns; however, the underlying neurophysiologic mechanisms remain unclear. Objective: To compare limb symmetry of quadriceps neuromuscular function between participants with ACLR and participants serving as healthy controls. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: A total of 22 individuals with ACLR (12 men, 10 women) and 24 individuals serving as healthy controls (12 men, 12 women). Main Outcome Measure(s): Normalized knee-extension maximal voluntary isometric contraction (MVIC) torque (Nm/kg), quadriceps central activation ratio (CAR) (%), quadriceps motor-neuron–pool excitability (Hoffmann reflex to motor wave ratio), and quadriceps active motor threshold (AMT) (% 2.0 T) were measured bilaterally and used to calculate limb symmetry indices for comparison between groups. We used analyses of variance to compare quadriceps Hoffmann reflex to motor wave ratio, normalized knee-extension MVIC torque, quadriceps CAR, and quadriceps AMT between groups and limbs. Results: The ACLR group exhibited greater asymmetry in knee-extension MVIC torque (ACLR group = 0.85 ± 0.21, healthy group = 0.97 ± 0.14; t44 = 2.26, P = .03), quadriceps CAR (ACLR group = 0.94 ± 0.11, healthy group = 1.00 ± 0.08; t44 = 2.22, P = .04), and quadriceps AMT (ACLR group = 1.13 ± 0.18, healthy group = 1.02 ± 0.11; t34 = −2.46, P = .04) than the healthy control group. Conclusions: Asymmetries in measures of quadriceps function and cortical excitability were present in patients with ACLR. Asymmetry in quadriceps strength, activation, and cortical excitability persisted in individuals with ACLR beyond return to recreational activity. Measuring the magnitude of asymmetry after ACLR represents an important step in understanding long-term reductions in self-reported function and increased rate of subsequent joint injury in otherwise healthy, active individuals after ACLR. PMID:25622244

  13. Does running strengthen bone?

    PubMed

    Boudenot, Arnaud; Achiou, Zahra; Portier, Hugues

    2015-12-01

    Bone is a living tissue needing mechanical stress to maintain strength. Traditional endurance exercises offer only modest effects on bone. Walking and running produce low impact but lead to bone fatigue. This article is specifically addressed to therapists and explains the mechanisms involved for the effects of exercise on bone. Intermittent exercise limits bone fatigue, and downhill exercises increase ground impact forces and involve eccentric muscle contractions, which are particularly osteogenic. PMID:26562001

  14. Quadriceps tendon allografts as an alternative to Achilles tendon allografts: a biomechanical comparison.

    PubMed

    Mabe, Isaac; Hunter, Shawn

    2014-12-01

    Quadriceps tendon with a patellar bone block may be a viable alternative to Achilles tendon for anterior cruciate ligament reconstruction (ACL-R) if it is, at a minimum, a biomechanically equivalent graft. The objective of this study was to directly compare the biomechanical properties of quadriceps tendon and Achilles tendon allografts. Quadriceps and Achilles tendon pairs from nine research-consented donors were tested. All specimens were processed to reduce bioburden and terminally sterilized by gamma irradiation. Specimens were subjected to a three phase uniaxial tension test performed in a custom environmental chamber to maintain the specimens at a physiologic temperature (37 ± 2 °C) and misted with a 0.9 % NaCl solution. There were no statistical differences in seven of eight structural and mechanical between the two tendon types. Quadriceps tendons exhibited a significantly higher displacement at maximum load and significantly lower stiffness than Achilles tendons. The results of this study indicated a biomechanical equivalence of aseptically processed, terminally sterilized quadriceps tendon grafts with bone block to Achilles tendon grafts with bone block. The significantly higher displacement at maximum load, and lower stiffness observed for quadriceps tendons may be related to the failure mode. Achilles tendons had a higher bone avulsion rate than quadriceps tendons (86 % compared to 12 %, respectively). This was likely due to observed differences in bone block density between the two tendon types. This research supports the use of quadriceps tendon allografts in lieu of Achilles tendon allografts for ACL-R. PMID:24414293

  15. FRP : Strengthened RC Structures

    NASA Astrophysics Data System (ADS)

    Teng, J. G.; Chen, J. F.; Smith, S. T.; Lam, L.

    2002-01-01

    The strengthening of reinforced concrete (RC) structures using advanced fibre-reinforced polymer (FRP) composites, and in particular the behaviour of FRP-strengthened RC structures is a topic which has become very popular in recent years. This popularity has arisen due to the need to maintain and upgrade essential infrastructure in all parts of the world, combined with the well-known advantages of FRP composites, such as good corrosion resistance and ease for site handling due to their light weight. The continuous reduction in the material cost of FRP composites has also contributed to their popularity. While a great amount of research now exists in the published literature on this topic, it is scattered in various journals and conference proceedings. This book therefore provides the first ever comprehensive, state-of-the-art summary of the existing research on FRP strengthening of RC structures, with the emphasis being on structural behaviour and strength models. The main topics covered include: Bond behaviour Flexural and shear strengthening of beams Column strengthening Flexural strengthening of slabs. For each area, the methods of strengthening are discussed, followed by a description of behaviour and failure modes and then the presentation of rational design recommendations, for direct use in practical design of FRP strengthening measures. Researchers, practicing engineers, code writers and postgraduate students in structural engineering and construction materials, as well as consulting firms, government departments, professional bodies, contracting firms and FRP material suppliers will find this an invaluable resource.

  16. Effects and feasibility of exercise therapy combined with branched-chain amino acid supplementation on muscle strengthening in frail and pre-frail elderly people requiring long-term care: a crossover trial.

    PubMed

    Ikeda, Takashi; Aizawa, Junya; Nagasawa, Hiroshi; Gomi, Ikuko; Kugota, Hiroyuki; Nanjo, Keigo; Jinno, Tetsuya; Masuda, Tadashi; Morita, Sadao

    2016-04-01

    This study examined the effects and feasibility of a twice-weekly combined therapy of branched-chain amino acids (BCAAs) and exercise on physical function improvement in frail and pre-frail elderly people requiring long-term care. We used a crossover design in which the combination of exercise and nutritional interventions was carried out twice a week during cycles A (3 months) and B (3 months) and the exercise intervention alone was performed during the washout period. The exercise intervention entailed the following 5 training sets: 3 sets of muscle training at 30% of maximum voluntary contraction, 1 set of aerobic exercise, and 1 set of balance training. For the nutritional intervention, 6 g of BCAAs or 6 g of maltodextrin was consumed 10 min before starting the exercise. We determined upper and lower limb isometric strength, performance on the Functional Reach Test (FRT) and the Timed Up and Go test, and activity level. In the comparison between the BCAA group and the control group after crossover, the improvement rates in gross lower limb muscle strength (leg press, knee extension) and FRT performance were significantly greater (by approximately 10%) in the BCAA group. In the comparison between different orders of BCAA administration, significant effects were shown for the leg press in both groups only when BCAAs were given. The combination of BCAA intake and exercise therapy yielded significant improvements in gross lower limb muscle strength and dynamic balance ability. PMID:26963483

  17. Contributors to Fatigue Resistance of the Hamstrings and Quadriceps in Cerebral Palsy

    PubMed Central

    Moreau, Noelle G; Li, Li; Geaghan, James P; Damiano, Diane L

    2009-01-01

    Background The purpose of this study was to elucidate relationships between quadriceps and hamstrings voluntary muscle fatigue and upper motor lesion impairments in cerebral palsy in order to gain a better understanding of their contribution to the observed fatigue resistance. Methods Seventeen ambulatory subjects with cerebral palsy (mean age: 17.0, SD = 4.8 years) were recruited. Quantitative measures of strength, spasticity, cocontraction, and stiffness for both muscle groups were collected on an isokinetic dynamometer and entered in a factor analysis. The resulting factors were used as independent variables in a multiple regression analysis with quadriceps and hamstrings fatigue as dependent variables. Findings Five independent factors explained 90% of the variance. In order of loadings, higher hamstring cocontraction and spasticity and lower hamstring strength were associated with lower levels of hamstring fatigue. Higher quadriceps cocontraction and lower quadriceps strength were the most predictive of lower levels of quadriceps fatigue. Interpretation Greater motor impairments of the agonist muscle, particularly cocontraction, spasticity, and weakness, were associated with lower rates of muscle fatigue of the same muscle during performance of a voluntary fatigue protocol for the hamstrings and quadriceps. Muscles are highly adaptable; therefore, the results of this study suggest that the observed fatigue resistance may be due to the effect of the primary neural insult on motor unit recruitment and rate modulation or the result of secondary adaptations to spasticity, weakness, or excessive cocontraction. PMID:19264384

  18. Correlation between Quadriceps Endurance and Adduction Moment in Medial Knee Osteoarthritis

    PubMed Central

    Ahn, Sung-Eun; Park, Min-Ji; Lee, Dae-Hee

    2015-01-01

    It is not clear whether the strength or endurance of thigh muscles (quadriceps and hamstring) is positively or negatively correlated with the adduction moment of osteoarthritic knees. This study therefore assessed the relationships between the strength and endurance of the quadriceps and hamstring muscles and adduction moment in osteoarthritic knees and evaluated predictors of the adduction moment. The study cohort comprised 35 patients with unilateral medial osteoarthritis and varus deformity who were candidates for open wedge osteotomy. The maximal torque (60°/sec) and total work (180°/sec) of the quadriceps and hamstring muscles and knee adduction moment were evaluated using an isokinetic testing device and gait analysis system. The total work of the quadriceps (r = 0.429, P = 0.037) and hamstring (r = 0.426, P = 0.045) muscles at 180°/sec each correlated with knee adduction moment. Preoperative varus deformity was positively correlated with adduction moment (r = 0.421, P = 0.041). Multiple linear regression analysis showed that quadriceps endurance at 180°/sec was the only factor independently associated with adduction moment (β = 0.790, P = 0.032). The adduction moment of osteoarthritic knees correlated with the endurance, but not the strength, of the quadriceps muscle. However, knee adduction moment did not correlate with the strength or endurance of the hamstring muscle. PMID:26539830

  19. Corticospinal and Intracortical Excitability of the Quadriceps in Patients with Knee Osteoarthritis

    PubMed Central

    Kittelson, Andrew J.; Thomas, Abbey C.; Kluger, Benzi M.; Stevens-Lapsley, Jennifer E.

    2015-01-01

    Deficits in voluntary activation of the quadriceps muscle are characteristic of knee osteoarthritis (OA), contributing to the quadriceps weakness that is also a hallmark of the disease. The mechanisms underlying this central activation deficit (CAD) are unknown, although cortical mechanisms may be involved. Here, we utilize transcranial magnetic stimulation (TMS) to assess corticospinal and intracortical excitability in patients with knee osteoarthritis (OA) and in a comparably aged group of healthy older adults, to quantify group differences and to examine associations between TMS measures and pain, quadriceps strength, and CAD. Seventeen patients with knee OA and 20 healthy controls completed testing. Motor evoked potentials (MEPs) were measured at the quadriceps by superficial electromyographic (EMG) recordings. Corticospinal excitability was assessed by measuring resting motor threshold (RMT) to TMS stimulation of the quadriceps representation at primary motor cortex, and intracortical excitability was assessed via paired pulse paradigms for short interval intracortical inhibition (SICI) and intracortical facilitation (ICF). No statistically significant differences between patients with knee OA and healthy controls were found for RMT, SICI or ICF measures (p>0.05). For patients with knee OA, there were significant associations observed between pain and RMT, as well as between pain and ICF. No associations were observed between CAD and measures of corticospinal or intracortical excitability. These data suggest against direct involvement of corticospinal or intracortical pathways within primary motor cortex in the mechanisms of CAD. However, pain is implicated in the neural mechanisms of quadriceps motor control in patients with knee OA. PMID:25183161

  20. Effects of Kinesiology Taping on Repositioning Error of the Knee Joint after Quadriceps Muscle Fatigue

    PubMed Central

    Han, Jin Tae; Lee, Jung-hoon

    2014-01-01

    [Purpose] The purpose of this study was to identify the effects of kinesiology taping on repositioning error of the knee joint after quadriceps muscle fatigue. [Subjects] Thirty healthy adults with no orthopaedic or neurological problems participated in this study. [Methods] The repositioning error of the knee joint was measured using a digital goniometer when the subjects extended their dominant-side knee to a random target angle (30°, 45°, or 60°) with their eyes closed, before and after a quadriceps muscle fatigue protocol, and after application of kinesiology tape. [Results] We found that repositioning errors of the dominant-side knee joint increased after quadriceps fatigue compared with no-fatigue conditions. However, kinesiology taping of the quadriceps muscle and patella after quadriceps fatigue significantly decreased repositioning errors of the knee joint. [Conclusion] These results suggest that quadriceps fatigue increases the repositioning error of the knee joint, whereas application of kinesiology tape decreases fatigue-induced joint repositioning error. PMID:25013297

  1. Effects of kinesiology taping on repositioning error of the knee joint after quadriceps muscle fatigue.

    PubMed

    Han, Jin Tae; Lee, Jung-Hoon

    2014-06-01

    [Purpose] The purpose of this study was to identify the effects of kinesiology taping on repositioning error of the knee joint after quadriceps muscle fatigue. [Subjects] Thirty healthy adults with no orthopaedic or neurological problems participated in this study. [Methods] The repositioning error of the knee joint was measured using a digital goniometer when the subjects extended their dominant-side knee to a random target angle (30°, 45°, or 60°) with their eyes closed, before and after a quadriceps muscle fatigue protocol, and after application of kinesiology tape. [Results] We found that repositioning errors of the dominant-side knee joint increased after quadriceps fatigue compared with no-fatigue conditions. However, kinesiology taping of the quadriceps muscle and patella after quadriceps fatigue significantly decreased repositioning errors of the knee joint. [Conclusion] These results suggest that quadriceps fatigue increases the repositioning error of the knee joint, whereas application of kinesiology tape decreases fatigue-induced joint repositioning error. PMID:25013297

  2. Exercise: Benefits of Exercise

    MedlinePLUS Videos and Cool Tools

    ... please turn Javascript on. Exercise: Benefits of Exercise Health Benefits One of the Healthiest Things You Can ... yourself. Studies have shown that exercise provides many health benefits and that older adults can gain a ...

  3. Optimal Burst Duration During a Facilitated Quadriceps Femoris Contraction

    PubMed Central

    McLoda, Todd A.; Carmack, Jennifer A.

    2000-01-01

    Objective: To determine the most efficient burst duty cycle for eliciting an involuntary quadriceps femoris contraction in healthy subjects. This information will allow clinicians to make an informed decision about the optimal burst duty cycle based upon a specific treatment goal. The logical goal for such a treatment choice is to enhance motor unit recruitment in an effort to maintain postoperative or postinjury strength, when voluntary contractions may be less effective. Design and Setting: Single-group and 5-measures design. All tests were performed in a university laboratory. Subjects: Forty-eight healthy subjects (27 men and 21 women; mean age, 26.4 ± 8.5 years) performed a maximal voluntary isometric contraction (MVIC) on an isokinetic device and received neuromuscular electrical stimulation (NMES) at 5 different burst duty cycles. Measurements: Subjects first performed an MVIC for knee extension on an isokinetic dynamometer at 60° of knee flexion. NMES surface electrodes were applied to the quadriceps muscle of each subject's dominant leg. The values for the NMES were 2500-Hz carrier frequency, 50-bursts-per-second treatment frequency, amplitude increased to maximum tolerance, and burst duty cycle set to each of the 5 comparison values. The peak isometric force generated by each of the 5 nonvolitional contractions was recorded, along with the maximal charge per burst tolerated by each subject. Force generated was described as percentage of MVIC. Efficiency was the amount of force per burst charge. Results: The mean MVIC achieved by the subjects was 553.8 newtons (N). The average force per burst charge generated at 10% burst duty cycle was 132.9 N; at 30%, 104.2 N; at 50%, 93.1 N; at 70%, 52.9 N; and at 90%, 41.3 N. The average efficiency (force per millicoulombs [mC]) at 10% burst duty cycle was the highest at 6.49 N/mC and at 90% was the lowest at 1.05 N/mC. Conclusions: A burst duty cycle of 10% was the most efficient ratio of burst duration to interburst interval duration for eliciting the strongest muscle contraction. Use of this preferred duty cycle enabled only 8 of 48 subjects (16.6%) to achieve 60% MVIC within 1 trial in 1 session of NMES. Twenty-five subjects (52.0%) were able to achieve at least 10% of the MVIC in the same trial period. PMID:16558623

  4. Influence of Anterior Cruciate Ligament Tear on Thigh Muscle Strength and Hamstring-to-Quadriceps Ratio: A Meta-Analysis

    PubMed Central

    Ahn, Sung-Eun; Park, Min-Ji; Lee, Dae-Hee

    2016-01-01

    Theoretical compensation after anterior cruciate ligament (ACL) tear could cause quadriceps weakness and hamstring activation, preventing anterior tibial subluxation and affecting the expected hamstring-to-quadriceps ratio. Although quadriceps weakness often occurs after ACL tears, it remains unclear whether hamstring strength and hamstring-to-quadriceps ratio increase in ACL deficient knees. This meta-analysis compared the isokinetic muscle strength of quadriceps and hamstring muscles, and the hamstring-to-quadriceps ratio, of the injured and injured limbs of patients with ACL tears. This meta-analysis included all studies comparing isokinetic thigh muscle strengths and hamstring-to-quadriceps ratio in the injured and uninjured legs of patients with ACL tear, without or before surgery. Thirteen studies were included in the meta-analysis. Quadriceps and hamstring strengths were 22.3 N∙m (95% CI: 15.2 to 29.3 N∙m; P<0.001) and 7.4 N∙m (95% CI: 4.3 to 10.5 N∙m; P<0.001) lower, respectively, on the injured than on the uninjured side. The mean hamstring-to-quadriceps ratio was 4% greater in ACL deficient than in uninjured limbs (95% CI: 1.7% to 6.3%; P<0.001). Conclusively, Decreases were observed in both the quadriceps and hamstring muscles of patients with ACL tear, with the decrease in quadriceps strength being 3-fold greater. These uneven reductions slightly increase the hamstring-to-quadriceps ratio in ACL deficient knees. PMID:26745808

  5. Altered Energetics of Exercise Explain Risk of Rhabdomyolysis in Very Long-Chain Acyl-CoA Dehydrogenase Deficiency

    PubMed Central

    Diekman, E. F.; Visser, G.; Schmitz, J. P. J.; Nievelstein, R. A. J.; de Sain-van der Velden, M.; Wardrop, M.; Van der Pol, W. L.; Houten, S. M.; van Riel, N. A. W.; Takken, T.; Jeneson, J. A. L.

    2016-01-01

    Rhabdomyolysis is common in very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) and other metabolic myopathies, but its pathogenic basis is poorly understood. Here, we show that prolonged bicycling exercise against a standardized moderate workload in VLCADD patients is associated with threefold bigger changes in phosphocreatine (PCr) and inorganic phosphate (Pi) concentrations in quadriceps muscle and twofold lower changes in plasma acetyl-carnitine levels than in healthy subjects. This result is consistent with the hypothesis that muscle ATP homeostasis during exercise is compromised in VLCADD. However, the measured rates of PCr and Pi recovery post-exercise showed that the mitochondrial capacity for ATP synthesis in VLCADD muscle was normal. Mathematical modeling of oxidative ATP metabolism in muscle composed of three different fiber types indicated that the observed altered energy balance during submaximal exercise in VLCADD patients may be explained by a slow-to-fast shift in quadriceps fiber-type composition corresponding to 30% of the slow-twitch fiber-type pool in healthy quadriceps muscle. This study demonstrates for the first time that quadriceps energy balance during exercise in VLCADD patients is altered but not because of failing mitochondrial function. Our findings provide new clues to understanding the risk of rhabdomyolysis following exercise in human VLCADD. PMID:26881790

  6. Altered Energetics of Exercise Explain Risk of Rhabdomyolysis in Very Long-Chain Acyl-CoA Dehydrogenase Deficiency.

    PubMed

    Diekman, E F; Visser, G; Schmitz, J P J; Nievelstein, R A J; de Sain-van der Velden, M; Wardrop, M; Van der Pol, W L; Houten, S M; van Riel, N A W; Takken, T; Jeneson, J A L

    2016-01-01

    Rhabdomyolysis is common in very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) and other metabolic myopathies, but its pathogenic basis is poorly understood. Here, we show that prolonged bicycling exercise against a standardized moderate workload in VLCADD patients is associated with threefold bigger changes in phosphocreatine (PCr) and inorganic phosphate (Pi) concentrations in quadriceps muscle and twofold lower changes in plasma acetyl-carnitine levels than in healthy subjects. This result is consistent with the hypothesis that muscle ATP homeostasis during exercise is compromised in VLCADD. However, the measured rates of PCr and Pi recovery post-exercise showed that the mitochondrial capacity for ATP synthesis in VLCADD muscle was normal. Mathematical modeling of oxidative ATP metabolism in muscle composed of three different fiber types indicated that the observed altered energy balance during submaximal exercise in VLCADD patients may be explained by a slow-to-fast shift in quadriceps fiber-type composition corresponding to 30% of the slow-twitch fiber-type pool in healthy quadriceps muscle. This study demonstrates for the first time that quadriceps energy balance during exercise in VLCADD patients is altered but not because of failing mitochondrial function. Our findings provide new clues to understanding the risk of rhabdomyolysis following exercise in human VLCADD. PMID:26881790

  7. Serial Changes of Quadriceps and Hamstring Muscle Strength Following Total Knee Arthroplasty: A Meta-Analysis

    PubMed Central

    Ahn, Hyeong-Sik; Lee, Dae-Hee

    2016-01-01

    This meta-analysis was performed to analyze serial changes in thigh muscles, including quadriceps and hamstring muscles, from before to one year after total knee arthroplasty (TKA). All studies sequentially comparing isokinetic quadriceps and hamstring muscle strengths between the TKA side and the contralateral uninjured limb were included in this meta-analysis. Five studies with 7 cohorts were included in this meta-analysis. The mean differences in the strengths of quadriceps and hamstring muscles between the TKA and uninjured sides were greatest three months after surgery (26.8 N∙m, 12.8 N∙m, P<0.001), but were similar to preoperative level at six months (18.4 N∙m, 7.4 N∙m P<0.001) and were maintained for up to one year (15.9 N∙m, 4.1 N∙m P<0.001). The pooled mean differences in changes in quadriceps and hamstring strengths relative to preoperative levels were 9.2 N∙m and 4.9 N∙m, respectively, three months postoperatively (P = 0.041), but were no longer significant after six months and one year. During the year after TKA, quadriceps and hamstring muscle strengths were lowest after 3 months, recovering to preoperative level after six months, but not reaching the muscle strength on the contralateral side. Relative to preoperative levels, the difference in muscle strength between the TKA and contralateral knees was only significant at three months. Because decrease of strength of the quadriceps was significantly greater than decrease in hamstring muscle strength at postoperative three months, early rehabilitation after TKA should focus on recovery of quadriceps muscle strength. PMID:26849808

  8. In vivo specific tension of the human quadriceps femoris muscle.

    PubMed

    Erskine, Robert M; Jones, David A; Maganaris, Constantinos N; Degens, Hans

    2009-08-01

    It is not known to what extent the inter-individual variation in human muscle strength is explicable by differences in specific tension. To investigate this, a comprehensive approach was used to determine in vivo specific tension of the quadriceps femoris (QF) muscle (Method 1). Since this is a protracted technique, a simpler procedure was also developed to accurately estimate QF specific tension (Method 2). Method 1 comprised calculating patellar tendon force (F (t)) in 27 young, untrained males, by correcting maximum voluntary contraction (MVC) for antagonist co-activation, voluntary activation and moment arm length. For each component muscle, the physiological cross-sectional area (PCSA) was calculated as volume divided by fascicle length during MVC. Dividing F (t) by the sum of the four PCSAs (each multiplied by the cosine of its pennation angle during MVC) provided QF specific tension. Method 2 was a simplification of Method 1, where QF specific tension was estimated from a single anatomical CSA and vastus lateralis muscle geometry. Using Method 1, the variability in MVC (18%) and specific tension (16%) was similar. Specific tension from Method 1 (30 +/- 5 N cm(-2)) was similar to and correlated with that of Method 2 (29 +/- 5 N cm(-2); R (2) = 0.67; P < 0.05). In conclusion, most of the inter-individual variability in MVC torque remains largely unexplained. Furthermore, a simple method of estimating QF specific tension provided similar values to the comprehensive approach, thereby enabling accurate estimations of QF specific tension where time and resources are limited. PMID:19468746

  9. OPTOTRAK Measurement of the Quadriceps Angle Using Standardized Foot Positions

    PubMed Central

    Livingston, Lori A.; Spaulding, Sandi J.

    2002-01-01

    Objective: While there is evidence to suggest that the magnitude of the quadriceps (Q) angle changes with alterations in foot position, a detailed quantitative description of this relationship has not been reported. Our purpose was to determine the effect of varying foot placement on the magnitude of the Q angle. Design and Setting: A mixed between-within, repeated-measures design was used to compare Q angles derived under static weight-bearing conditions with the feet positioned in self-selected versus standardized stance positions. Subjects: Twenty healthy young-adult men and women with no history of acute injury to or chronic dysfunction of the lower limbs. Measurements: We placed light-emitting diodes bilaterally on the left and right anterior superior iliac spines, the tibial tuberosities, and the midpoints of the patellae to bilaterally define the Q angles. An OPTOTRAK motion-measurement system was used to capture x,y coordinate data at a sampling rate of 60 Hz. These data were subsequently filtered and used to calculate the magnitude of the left and right Q angles. Results: A repeated-measures analysis of variance revealed that when measured statically, Q angles differed significantly between stance positions (P < .001) and limbs (P < .05). Depending on the stance adopted, mean Q angles varied from 7.2° to 12.7° and 11.0° to 16.1° in the left and right lower limbs, respectively. Q-angle measurements taken in conjunction with the Romberg foot position most closely resembled those gathered with the feet in a self-selected stance (Pearson r = 0.86 to 0.92). Conclusions: Q-angle magnitude varies with changes in foot position, increasing or decreasing as the foot rotates internally or externally, respectively. These data demonstrate the need for a standardized foot position for Q-angle measurements. PMID:12937581

  10. ASSOCIATION BETWEEN LONG-TERM QUADRICEPS WEAKNESS AND EARLY WALKING MUSCLE CO-CONTRACTION AFTER TOTAL KNEE ARTHROPLASTY

    PubMed Central

    Yoshida, Yuri; Mizner, Ryan L.; Snyder-Mackler, Lynn

    2013-01-01

    INTRODUCTION Quadriceps weakness is one of the primary post-operative impairments that persist long term for patients after total knee arthroplasty (TKA). We hypothesized that early gait muscle recruitment patterns of the quadriceps and hamstrings with diminished knee performance at 3 months after surgery would be related to long-term quadriceps strength at one year after TKA. METHODS Twenty-one subjects who underwent primary unilateral TKA and 14 age-matched healthy controls were analyzed. At three months after TKA, the maximum voluntary isometric contraction of quadriceps and a comprehensive gait analysis were performed. Quadriceps strength was assessed again at one year after surgery. RESULTS Quadriceps muscle recruitment of the operated limb was greater than the non-operated limb during the loading response of gait (p=0.03), but there were no significant differences in hamstring recruitment or co-contraction between limbs (p>0.05). There were significant differences in quadriceps muscle recruitment during gait between the non-operated limb of TKA group and healthy control group (p<0.05). The TKA group showed a significant inverse relationship between one year quadriceps strength and co-contraction (r = −0.543) and hamstring muscle recruitment (r = −0.480) during loading response at 3 months after TKA. CONCLUSIONS The results revealed a reverse relationship where stronger patients tended to demonstrate lower quadriceps recruitment at 3 months post-surgery that was not observed in the healthy peer group. The altered neuromuscular patterns of quadriceps and hamstrings during gait may influence chronic quadriceps strength in individuals after TKA. PMID:23352711

  11. Medial Quadriceps Tendon–Femoral Ligament: Surgical Anatomy and Reconstruction Technique to Prevent Patella Instability

    PubMed Central

    Fulkerson, John P.; Edgar, Cory

    2013-01-01

    Detailed anatomic dissections of the deep medial knee retinaculum have shown a consistent prominent anatomic structure extending from the distal deep quadriceps tendon to the adductor tubercle region, forming a distinct medial quadriceps tendon–femoral ligament (MQTFL). Reconstruction of this anatomic structure has yielded consistent medial stabilization of the patellofemoral joint without drilling into the patella over more than 3 years in patients with recurrent patella instability and dislocation. Results are similar to those of MPFL reconstruction but with reduced risk of patella fracture, a known and serious complication of MPFL reconstruction. The reconstruction graft is secured at the anatomic femoral origin of the MQTFL and brought under the vastus medialis such that it may be woven and attached to the deep distal medial quadriceps tendon to provide a secure, reliable reproduction of the MQTFL and excellent stabilization of the patellofemoral joint without risk of patella fracture. PMID:23875137

  12. Synchronous quadriceps tendon rupture and unilateral ACL tear in a weightlifter, associated with anabolic steroid use.

    PubMed

    Fenelon, Christopher; Dalton, David M; Galbraith, John G; Masterson, Eric L

    2016-01-01

    Synchronous quadriceps tendon rupture is rare. A 29-year-old man, an amateur weight lifter, taking androgenic-anabolic steroids (AAS), developed sudden onset bilateral pain and swelling of his anterior thighs when attempting to squat 280 kg (620 lb). Examination revealed gross swelling superior to the patella and palpable gaps in both quadriceps tendons. He underwent successful operative repair. MRI revealed a partial tear of the anterior cruciate ligament (ACL) of the right knee. This was not reconstructed. Only a few case reports of the association between AAS and quadriceps rupture exist in the literature, with none to the best of our knowledge in the past 10 years. ACL rupture coexisting is very rare, with only two reported cases. PMID:27154985

  13. Restorative Effect of Vitamin D Deficiency on Knee Pain and Quadriceps Muscle Strength in Knee Osteoarthritis.

    PubMed

    Heidari, Behzad; Javadian, Yahya; Babaei, Mansour; Yousef-Ghahari, Behnaz

    2015-08-01

    Both vitamin D deficiency and quadriceps muscle weakness are associated with knee osteoarthritis (KOA) and pain. The aim of this study was to determine the restorative effect of vitamin D deficiency on pain and quadriceps muscle strength in knee osteoarthritis. Patients with KOA aged ≥30 years, the presence of knee pain for at least one month or longer and serum 25-hydroxyvitamin (25-OHD) deficiencies were recruited in the study. Participants with KOA compatible with Kellgren-Lawrence grade 4, joint instability, and effusion, history of surgery or inflammatory arthropathies were excluded. Serum 25-OHD was assessed by ELISA method and concentrations<20 ng/ml was considered deficiency. Quadriceps muscle strength was measured by dynamometry method and intensity of knee pain by Western Ontario and McMaster University Osteoarthritis index scored by Likert scale and visual analog scale. All participants received 50.000 IU oral cholecalciferol weekly for at least two months. The influence of raising serum 25-OHD on quadriceps muscle strength and pain was assessed by calculation of mean changes from baseline at the end of the treatment period using paired t-test. A total of 67 patients with mean age of 50±6.6 years of age were treated for 2 months. Serum 25-OHD reached to sufficient levels in all except one patient. At the end of the study period, serum 25-OHD and quadriceps muscle strength increased significantly as compared with baseline (P=0.007 and P=0.002, respectively), whereas knee pain decreased significantly based on Western Ontario and McMaster University Osteoarthritis index (P=0.001)as well as visual analogue scale scores (P=0.001). These findings indicated that correction of vitamin D deficiency in patients with KOA exerts a significant favorable effect on quadriceps muscle strength and knee pain. PMID:26545990

  14. Effects of Sacroiliac Joint Mobilization on Hamstring Muscle Flexibility and Quadriceps Muscle Strength

    PubMed Central

    Tamer, Seval; Öz, Müzeyyen; Ülger, Özlem

    2014-01-01

    Objectives: The aim of this study was to determine the effect of sacroiliac joint mobilization (SJM) in cases with sacroiliac joint dysfunction (SJD) on hamstring muscle flexibility and quadriceps muscle strength. Methods: Seven subjects age average (min- max) was 21.85 (21-23) years with SJD were included. Hamstring muscle flexibility was measured with passive knee extension (PKE) method by using goniometer; quadriceps muscle strength was measured by using a hand dynamometer. After osteopathic evaluation (sacroiliac joint stress and mobility tests) appropriate mobilization methods (ilium anterior, ilium posterior and sacrum R / R dysfunction mobilization) were performed in patients with sacroiliac joint dysfunction. All measurements were repeated before, immediately and 4 days after application. For statistical analysis, Friedman and Wilcoxon-Signed test was used. Results: Immediately after SIJ mobilization for 7 patients, hamstring muscle flexibility was evaluated and compared with pretreatment status; bilateral hamstring muscle flexibility improvement was observed (p <0.05). When the results at 4 days were compared with the pretreatment measurements, generated effect continued in the dominant side (p <0.05) and there were no changes observed in the non-dominant side (p> 0.05). When immediate and 4th-day measurements were compared, bilateral improvement was maintained(p> 0.05). When pretreatment and immediate posttreatment rsults were analysed, bilateral quadriceps muscle strength was found to be increased (p <0.05). When 4th- day and pretreatment measures were compared the effects were bilaterally maintained (p <0.05). Comparison of immediate postapplication and 4th-day measurements revealed that bilateral improvement continued (p> 0.05). Conclusion: In SJD patients known with hamstring muscle flexibility loss and quadriceps muscle weakness, private sacroiliac joint mobilization is effective in enhancing hamstring muscle flexibility and quadriceps muscle strength, so SJD could be considered for increasing quadriceps muscle strength and hamstring muscle flexibility.

  15. Simultaneous Bilateral Quadriceps Tendon Rupture following Long-Term Low-Dose Nasal Corticosteroid Application

    PubMed Central

    Ettinger, Max; Krettek, Christian

    2013-01-01

    Simultaneous bilateral quadriceps tendon rupture is a very rare injury, which was previously only described in slightly more than 100 cases in the English literature. Occurrence after minor trauma is predominantly associated with certain medical conditions including chronic diseases and long-term use of certain drugs. We report the case of a 61-year-old healthy patient who sustained a simultaneous bilateral quadriceps tendon rupture following minor trauma. Medical history was completely clear except of a long-term nasal corticosteroid medication due to allergic rhinitis. PMID:23984143

  16. Contribution of Quadriceps Weakness to Fragility Fracture: A Prospective Study.

    PubMed

    Pham, Hanh M; Nguyen, Nguyen D; Center, Jacqueline R; Eisman, John A; Nguyen, Tuan V

    2016-01-01

    The association between muscle weakness and fracture is not well understood. This study sought to examine the contribution of muscle strength at baseline and change in muscle strength to the observed risk of fragility fracture in older people. The study involved 595 men and 1066 women aged 60+ years (median 69 years) who had been followed for a median of 11 years (range, 4 to 22 years). Quadriceps isometric muscle strength (MS) measured at baseline and biennially was adjusted for height. Femoral neck bone mineral density (FNBMD) was measured by DXA. Low-trauma fracture was ascertained from X-ray reports and interview. The relationship between baseline MS and serial MS and fracture assessed by time-invariant and time-variant Cox's regression models was expressed as hazard ratio (HR) and 95% confidence interval (CI). During the follow-up period, 282 (26%) women and 89 (15%) men sustained a fragility fracture. From age 60 years, women lost 0.28 kg/m (1.6%) of MS per year, whereas men lost 0.39 kg/m (1.5%) of MS per year. In the time-variant model, using serial MS, each 1 SD (4.7 kg/m) lower MS was associated with a 27% increase in the risk of fracture in women (HR 1.27; 95% CI, 1.11 to 1.43); and 46% increase in men (HR 1.46; 95% CI, 1.22 to 1.75). After adjusting for FNBMD, age and prior fracture, history of fall and smoking, HR per SD of lower MS was 1.13 (95% CI, 0.99 to 1.28) for women and 1.35 (95% CI, 1.18 to 1.64) for men. These data indicate that muscle weakness is an independent determinant of fracture risk in men, but not in women. This sex difference suggests that apart from mechanical load effect of muscle on bone, there are other muscle-bone interactions that need to be investigated in future studies. The accuracy of fracture risk prediction for men may be improved by incorporating muscle strength. PMID:26174768

  17. as the Strengthening Precipitates

    NASA Astrophysics Data System (ADS)

    Lu, Qi; Xu, Wei; van der Zwaag, Sybrand

    2014-12-01

    Generally, Laves phase and M23C6 are regarded as undesirable phases in creep-resistant steels due to their very high-coarsening rates and the resulting depletion of beneficial alloying elements from the matrix. In this study, a computational alloy design approach is presented to develop martensitic steels strengthened by Laves phase and/or M23C6, for which the coarsening rates are tailored such that they are at least one order of magnitude lower than those in existing alloys. Their volume fractions are optimized by tuning the chemical composition in parallel. The composition domain covering 10 alloying elements at realistic levels is searched by a genetic algorithm to explore the full potential of simultaneous maximization of the volume fraction and minimization of the precipitates coarsening rate. The calculations show that Co and W can drastically reduce the coarsening rate of Laves and M23C6 and yield high-volume fractions of precipitates. Mo on the other hand was shown to have a minimal effect on coarsening. The strengthening effects of Laves phase and M23C6 in the newly designed alloys are compared to existing counterparts, showing substantially higher precipitation-strengthening contributions especially after a long service time. New alloys were designed in which both Laves phase and M23C6 precipitates act as strengthening precipitates. Successfully combining MX and M23C6 was found to be impossible.

  18. Strengthening Resilience in Families

    ERIC Educational Resources Information Center

    Guild, Diane; Espiner, Deborah

    2014-01-01

    Rolling with Resilience (RwR) provides a springboard for developing strategies that build strengths and supports to foster developmental assets in children and youth (Benson, Scales, & Roehlkepartain, 2011). In Circle of Courage terms, resilience is strengthened by opportunities for Belonging, Mastery, Independence, and Generosity (Brendtro,…

  19. Dispersion strengthened copper

    DOEpatents

    Sheinberg, H.; Meek, T.T.; Blake, R.D.

    1990-01-09

    A composition of matter is described which is comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide. A method for making this composition of matter is also described. This invention relates to the art of powder metallurgy and, more particularly, it relates to dispersion strengthened metals.

  20. Strengthening Resilience in Families

    ERIC Educational Resources Information Center

    Guild, Diane; Espiner, Deborah

    2014-01-01

    Rolling with Resilience (RwR) provides a springboard for developing strategies that build strengths and supports to foster developmental assets in children and youth (Benson, Scales, & Roehlkepartain, 2011). In Circle of Courage terms, resilience is strengthened by opportunities for Belonging, Mastery, Independence, and Generosity (Brendtro,

  1. Physiological responses during downhill walking: A new exercise modality for subjects with chronic obstructive pulmonary disease?

    PubMed

    Camillo, Carlos Augusto; Burtin, Chris; Hornikx, Miek; Demeyer, Heleen; De Bent, Kristien; van Remoortel, Hans; Osadnik, Christian R; Janssens, Wim; Troosters, Thierry

    2015-05-01

    Skeletal muscle quadriceps low-frequency fatigue (LFF) during exercise promotes improvements in exercise capacity with exercise training. In healthy subjects, eccentric muscle work induced by downhill walking (DW) generates higher muscular stress, whilst metabolic cost is lower compared to level walking (LW). We investigated quadriceps LFF and metabolic cost of DW in patients with chronic obstructive pulmonary disease. Ten participants (67 ± 7 years, FEV1 51 ± 15% predicted) performed DW, DW carrying a load (DWL) of 10% body weight via vest and LW, in random order. Quadriceps potentiated twitch force (TWqpot) was assessed before and after each walk, and muscle damage was assessed before and 24 hours after each walk via serum creatine kinase (CK) levels. Ventilation (VE) and oxygen consumption (VO2) were measured via breath-by-breath analysis during each walk. DW and DWL resulted in a greater decrease in TWqpot (-30 ± 14 N in DW, p < 0.05; and -22 ± 16 N in DWL, p < 0.05) compared to LW (-3 ± 21 N, p > 0.05). CK levels only increased 24 hours following DW and DWL (p < 0.05). DW and DWL showed lower VE and VO2 than LW (p < 0.05). DW is associated with enhanced quadriceps LFF and lower cardiorespiratory costs than LW. The addition of a chest load to DW does not seem to enhance these effects. PMID:25758676

  2. Effects of trunk-hip strengthening on standing in children with spastic diplegia: a comparative pilot study

    PubMed Central

    Kim, Joong-Hwi; Seo, Hye-Jung

    2015-01-01

    [Purpose] This study evaluated the effects of trunk-hip strengthening exercise on trunk-hip activation and pelvic tilt motion during standing in children with spastic diplegia and compared the improvement of pelvic tilt between the modified trunk-hip strengthening exercise and conventional exercise. [Subjects and Methods] Ten ambulant children with spastic diplegia were randomized to the modified trunk-hip strengthening exercise (n = 5) or conventional exercise (n = 5) group. The intervention consisted of a 6-week modified trunk-hip strengthening exercise 3 times per week. The children were tested for trunk-hip muscles activation and pelvic tilt motion during standing by surface electromyography and an inclinometer before and after the intervention. [Results] The anterior pelvic tilt angle and activation of the extensor spinae, rectus femoris, and semitendinosus during standing decreased significantly in the modified exercise group. The activation of extensor spinae differed significantly between groups. [Conclusion] Compared to the conventional exercise, the modified exercise was more effective for trunk-hip activation improvement and anterior pelvic tilt motion decrease during standing in children with spastic diplegia. We suggest clinicians use an individually tailored modified trunk-hip strengthening exercise for strengthening the weakest muscle groups in children with standing ability problems. PMID:26157214

  3. Relationship between knee alignment and the electromyographic activity of quadriceps muscles in patients with knee osteoarthritis

    PubMed Central

    Lim, Seong Hoon; Hong, Bo Young; Oh, Jee Hae; Lee, Jong In

    2015-01-01

    [Purpose] We evaluated the relationship between knee alignment and the electromyographic (EMG) activity of the vastus medialis (VM) to the vastus lateralis (VL) muscles in patients with knee osteoarthritis (OA) in a cross-sectional study. [Subjects and Methods] Forty subjects with knee OA were assessed by anatomic radiographic knee alignment and the VM/VL ratio was calculated. Surface EMG from both the VM and VL muscles were evaluated during maximal isometric contraction at 60° knee flexion. Simultaneously, peak quadriceps torque was assessed using an isokinetic dynamometer. Subjects were categorized into low, moderate, and high varus groups according to knee malalignment. The peak quadriceps torque and VM/VL ratio across groups, and their relationships with varus malalignment were analyzed. [Results] All subjects had medial compartment OA and the VM/VL ratio of all subjects was 1.31 ± 0.28 (mean ± SD). There were no significant differences in the peak quadriceps torque or VM/VL ratios across the groups nor were there any significant relationships with varus malalignment. [Conclusion] The VM/VL ratio and peak quadriceps torque were not associated with the severity of knee varus malalignment. PMID:25995602

  4. Rupture of the quadriceps tendon. A case report in a young dog.

    PubMed

    Arnault, F; Dembour, T; Gallois Bride, H; Chancrin, J L

    2009-01-01

    A five-month-old, male, 16 kg, mixed breed dog was presented for an acute non-weight bearing lameness of the right hind limb. A subtotal avulsion of the quadriceps tendon at its patellar insertion was diagnosed through radiography and ultrasonography. Two nylon sutures secured with a stainless steel crimp were placed in a locking loop pattern in the quadriceps tendon and through a transverse 2.7 mm drill-hole in the patella. No external coaptation was used postoperatively. A full functional recovery was observed, and was followed for one year postoperatively. Quadriceps tendon rupture has not been described in the veterinary literature to our knowledge; in humans, quadriceps tendon rupture is a well known entity, often due to systemic disease resulting in weakening of the tendinous structures. In the case presented herein, the dog's history, young age and location, without underlying biochemical abnormalities, led us to believe that the observed lesion was of traumatic origin. The surgical treatment performed was based on that performed in humans and also that which has been investigated experimentally in the dog. PMID:19151876

  5. The Gluteus Medius Vs. Thigh Muscles Strength Ratio and Their Relation to Electromyography Amplitude During a Farmer’s Walk Exercise

    PubMed Central

    Stastny, Petr; Lehnert, Michal; Zaatar, Amr; Svoboda, Zdenek; Xaverova, Zuzana; Pietraszewski, Przemysław

    2015-01-01

    The strength ratio between hamstrings and quadriceps (H/Q) is associated with knee injuries as well as hip abductor muscle (HAB) weakness. Sixteen resistance trained men (age, 32.5 ± 4.2 years) performed 5 s maximal isometric contractions at 75° of knee flexion/extension and 15° of hip abduction on a dynamometer. After this isometric test they performed a Farmer’s walk exercise to find out if the muscle strength ratio predicted the electromyography amplitude expressed as a percentage of maximum voluntary isometric contraction (%MVIC). The carried load represented a moderate intensity of 75% of the exercise six repetitions maximum (6RM). Electromyography data from the vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF) and gluteus medius (Gmed) on each leg were collected during the procedure. The groups selected were participants with H/Q ≥ 0.5, HQ < 0.5, HAB/H ≥ 1, HAB/H < 1, HAB/Q ≥ 0.5 and HAB/Q < 0.5. One way ANOVA showed that Gmed activity was significantly greater in the group with HAB/H < 1 (42 ± 14 %MVIC) as compared to HAB/H ≥ 1 (26 ± 10 %MVIC) and HAB/Q < 0.5 (47 ± 19 %MVIC) compared to HAB/Q ≥ 0.5 (26 ± 12 %MVIC). The individuals with HAB/H < 1 were found to have greater activation of their Gmed during the Farmer’s walk exercise. Individuals with HAB/Q < 0.5 had greater activation of the Gmed. Gmed strength ratios predict the muscle involvement when a moderate amount of the external load is used. The Farmer’s walk is recommended as an exercise which can strengthen the gluteus medius, especially for individuals with a HAB/H ratio < 1 and HAB/Q < 0.5. PMID:25964819

  6. The Effect of Knee Braces on Quadriceps Strength and Inhibition in Subjects With Patellofemoral Osteoarthritis.

    PubMed

    Callaghan, Michael J; Parkes, Matthew J; Felson, David T

    2016-01-01

    Study Design Secondary analysis of a randomized controlled trial. Background The use of external supports has been questioned because they may lead to weakness in the surrounding muscles. To our knowledge, there is no investigation into the effect of knee supports or braces on quadriceps muscle strength and quadriceps inhibition in individuals with patellofemoral joint (PFJ) osteoarthritis (OA). Objectives To investigate the effects of a flexible knee support on quadriceps maximum voluntary contraction (MVC) and arthrogenous muscle inhibition (AMI) in patients with PFJ OA. Methods The study included 108 participants who had at least 3 months of patellofemoral pain and a Kellgren-Lawrence score of 2 or 3 for PFJ OA. The participants were randomized to a group that wore a flexible knee support (brace) or a group that did not wear a support (no brace) in a 6-week randomized controlled trial, followed by an open-label trial, in which all participants wore the brace for a total of 12 weeks. Quadriceps MVC, measured isometrically, and quadriceps AMI, measured by twitch interpolation, were assessed at the 6-week and 12-week time points. Results After 6 weeks, MVC did not differ between the brace and no-brace groups (9.09 Nm; 95% confidence interval [CI]: -4.89, 23.07; P = .20). Arthrogenous muscle inhibition significantly decreased in the brace group (-8.62%; 95% CI: -13.90%, -3.33%; P = .002). After 12 weeks, in all of the participants who wore a flexible knee support, MVC increased by 7.98 Nm (95% CI: 2.52, 13.45; P = .004) and AMI decreased (-8.42%; 95% CI: -11.48%, -5.36%; P<.001). Although statistically significant, these results have doubtful clinical significance. Conclusion A patellofemoral flexible knee support in participants with PFJ OA does not have an adverse effect on quadriceps MVC or AMI. Using a knee support should not be discouraged because of concerns about deleterious effects on quadriceps strength and inhibition. Level of Evidence Therapy, level 1b. J Orthop Sports Phys Ther 2016;46(1):19-25. Epub 10 Nov 2015. doi:10.2519/jospt.2016.5093. PMID:26556391

  7. Quadriceps oxygenation changes during walking and running on a treadmill

    NASA Astrophysics Data System (ADS)

    Quaresima, Valentina; Pizzi, Assunta; De Blasi, Roberto A.; Ferrari, Adriano; de Angelis, Marco; Ferrari, Marco

    1995-04-01

    Vastus lateralis muscle oxygenation was investigated on volunteers as well as muscular dystrophy patients during a walking test, and on volunteers during a free running by a continuous wave near infrared instrument. The data were analyzed using an oxygenation index independent on pathlength changes. Walking did not significantly affect the oxygenation of volunteers and patients. A relative deoxygenation was found only during free running indicating an unbalance between oxygen supply and tissue oxygen extraction. Preliminary measurements of exercising muscle oxygen saturation were performed by a 110 MHz frequency-domain, multisource instrument.

  8. Quadriceps tendon rupture and periosteal sleeve avulsion fracture of the proximal patella pole in an active adolescent.

    PubMed

    Bimmel, R; Reddy, K

    2008-07-01

    A unique case of anterior knee pain in an active adolescent is described: a periosteal sleeve avulsion and quadriceps rupture in a young basketball player. The trauma mechanism was without any direct trauma on the knee. A review of overuse-related anterior knee pain in the young and active is presented. A quadriceps rupture with a periosteal sleeve avulsion fracture in an active adolescent is very rare. To our knowledge there are no similar cases described. This article presents a case of a 14-year-old adolescent boy who sustained a quadriceps rupture with a periosteal sleeve avulsion. PMID:19292365

  9. Blood pressure and heart rate responses during a fatiguing isometric exercise in paraplegic men with hypertension.

    PubMed

    Petrofsky, J S; Laymon, M

    2000-11-01

    A group of 45 male subjects were examined in a cross-sectional study to compare the blood pressure response that occurs during isometric exercise maintained to fatigue among control subjects and paraplegic patients with (PH) and without essential hypertension (PN). Two muscle groups were examined: the handgrip muscles (voluntary effort) and the quadriceps muscles. The tension chosen for the contraction was 40% of the muscles maximum strength for both muscle groups. While the paraplegic groups had more strength in their handgrip muscles than that found for the controls, the control subjects had more strength in their quadriceps muscles than either of the paraplegic groups. During the fatiguing isometric contractions, the rate of rise and absolute systolic blood pressure was higher in the PH than the other groups of subjects. The diastolic pressure of the PH group, while elevated during exercise, was only elevated to the same degree as the increase in resting diastolic pressure above normal. Heart rate changes during exercise was the same in all groups of subjects for handgrip contractions. The controls had the same heart rate response to handgrip as to leg exercise. The paraplegic groups showed no heart rate change during fatiguing contractions of their quadriceps muscles. The PH group actually showed a reduction in heart rate during the leg exercise. PMID:11138564

  10. Core stability exercise principles.

    PubMed

    Akuthota, Venu; Ferreiro, Andrea; Moore, Tamara; Fredericson, Michael

    2008-02-01

    Core stability is essential for proper load balance within the spine, pelvis, and kinetic chain. The so-called core is the group of trunk muscles that surround the spine and abdominal viscera. Abdominal, gluteal, hip girdle, paraspinal, and other muscles work in concert to provide spinal stability. Core stability and its motor control have been shown to be imperative for initiation of functional limb movements, as needed in athletics. Sports medicine practitioners use core strengthening techniques to improve performance and prevent injury. Core strengthening, often called lumbar stabilization, also has been used as a therapeutic exercise treatment regimen for low back pain conditions. This article summarizes the anatomy of the core, the progression of core strengthening, the available evidence for its theoretical construct, and its efficacy in musculoskeletal conditions. PMID:18296944

  11. Using squat testing to predict training loads for the deadlift, lunge, step-up, and leg extension exercises.

    PubMed

    Ebben, William P; Feldmann, Christina R; Dayne, Andrea; Mitsche, Diana; Chmielewski, Lauren M; Alexander, Paul; Knetgzer, Kenneth J

    2008-11-01

    The purpose of this study was to determine whether there is a linear relationship between the squat and a variety of quadriceps resistance training exercises for the purpose of creating prediction equations for the determination of quadriceps exercise loads based on the squat load. Six-repetition maximums (RMs) of the squat, as well as four common resistance training exercises that activate the quadriceps including the deadlift, lunge, step-up, and leg extension, were determined for each subject. Subjects included 21 college students. Data were evaluated using linear regression analysis to predict quadriceps exercise loads from 6RM squat data and were cross-validated with the prediction of sum of squares statistic. Analysis of the data revealed that the squat is a significant predictor of loads for the dead lift (R2 = 0.81, standard error of the estimate [SEE] = 12.50 kg), lunge (R2 = 0.62, SEE = 12.57 kg), step-up (R2 = 0.71, SEE = 9.58 kg), and leg extension (R2=0.67, SEE = 10.26 kg) exercises. Based on the analysis of the data, the following 6RM prediction equations were devised for each exercise: (a) deadlift load = squat load (0.83) + 14.92 kg, (b) lunge load = squat load (0.52) + 14.82 kg, (c) step-up load = squat load (0.50) + 3.32 kg, and (d) leg extension load = squat load (0.48) + 9.58 kg. Results from testing core exercises such as the squat can provide useful data for the assignment of loads for other exercises. PMID:18978614

  12. Evidence for interneuronally mediated Ia excitatory effects to human quadriceps motoneurones.

    PubMed Central

    Fournier, E; Meunier, S; Pierrot-Deseilligny, E; Shindo, M

    1986-01-01

    The possibility was investigated that interneuronal pathways contribute to Ia excitation of quadriceps motoneurones in normal man. Two techniques were used: the indirect spatial facilitation technique for investigating summation of Ia excitatory effects in interneurones which may be interposed in pathways to quadriceps motoneurones; the post-stimulus time histogram method for time course measurement of the firing probability of voluntarily activated motor units following femoral nerve stimulation. The spatial facilitation technique was applied while using the quadriceps H reflex to assess the excitability of the whole motoneurone pool: the comparison was made between the excitatory effects of two conditioning stimuli applied either separately or together. Summation of effects at a premotoneuronal level is suggested if facilitation of the reflex evoked on combined conditioning stimulation is larger than the algebraic sum of facilitations evoked by separate stimuli. Quadriceps tendon tap and electrical stimulations applied to either the femoral nerve or to two of its branches, the nerves to the vastus lateralis and vastus medialis muscles, were used as conditioning stimuli. Since these stimuli were very weak (their strength being about at the threshold for facilitation of the test reflex), it can be assumed that they activated predominantly Ia fibres. The facilitation of the quadriceps H reflex evoked on combined stimulation was significantly larger than the algebraic sum of facilitations evoked by separate stimuli. In many experiments, although conditioning stimuli did not evoke any reflex facilitation when applied alone, a significant facilitation appeared on combined stimulation. This 'extra' facilitation of the reflex on combined stimulation appeared with a central latency of 4-5 ms. It is argued that the only mechanism compatible with such a latency is summation at a premotoneuronal level. Post-stimulus time histograms (p.s.t.h.s) of voluntarily activated quadriceps motor units were made following femoral nerve stimulation. Stimulation was triggered at a fixed delay time after the activation of the motor unit. A special attempt was made to set this delay so that the motoneuronal after-hyperpolarization following the spike would partially prevent the discharge evoked by a monosynaptic excitatory post-synaptic potential (e.p.s.p.). At stimulus strengths near motor threshold, femoral nerve stimulation regularly evoked an early increase in firing probability of motor units with the same latency as the H reflex.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3795085

  13. Effect of time-dependent cryotherapy on redox balance of quadriceps injuries.

    PubMed

    Dos Santos Silva, Marco Aurélio; de Carvalho, Taiara Ramos; Marques Barros da Cruz, Amanda Cristina; Guedine de Jesus, Lennon Rafael; da Silva Neto, Larissa Alexsandra; Lima Trajano, Eduardo Tavares; Bezerra, Frank Silva

    2016-02-01

    Muscle trauma represents a high number of injuries in professional sport and recreation and may occur through several mechanisms. This study aims at analyzing time-dependent effects of cryotherapy on the redox balance in lesioned quadriceps muscles in F1 mice. Twenty male F1 mice were divided into five groups: (a) animals were not subjected to muscle lesioning or treatment (CTR); (b) quadriceps muscle was lesioned without treatment (L); (c) quadriceps muscle was lesioned and treated with cryotherapy for 5 min (LC5); (d) quadriceps muscle was lesioned and treated with cryotherapy for 20 min (LC20); and quadriceps muscle was lesioned and treated with cryotherapy for 40 min (LC40). The mice were euthanized; the quadriceps muscles were collected and subjected to analyses for levels of protein, hydroperoxides, nitrite, catalase (CAT) activity, oxidized glutathione (GSSG) and reduced glutathione (GSH). Protein levels were reduced in L (-39%; p < 0.05), LC5 (-54%; p < 0.05), LC20 (-40%; p < 0.05) and LC40 (-50%; p < 0.05) compared to CTR. There was an increase in lipid peroxidation in L (158%; p < 0.05), LC5 (300%; p < 0.01), LC20 (292%; p < 0.01) and LC40 (362%; p < 0.01) compared to CTR. We observed a significant increase in CAT activity in L (164%; p < 0.05) and LC5 (193%; p < 0.01) compared to CTR; a significant reduction in GSH in L (-60%; p < 0.05) and LC20 (-61%; p < 0.05) compared to CTR; and a significant increase in GSSG in LC5 (171%; p < 0.05) compared to CTR. In addition, GSH/GSSG was reduced in L (-89%; p < 0.01), LC5 (-95%; p < 0.01), LC20 (-59%; p < 0.05), and LC40 (-82%; p < 0.01) compared to CTR. This study showed that the cryotherapy does not improve the oxidative stress in lesioned muscles. PMID:26769009

  14. Effects of Directional Exercise on Lingual Strength

    ERIC Educational Resources Information Center

    Clark, Heather M.; O'Brien, Katy; Calleja, Aimee; Corrie, Sarah Newcomb

    2009-01-01

    Purpose: To examine the application of known muscle training principles to tongue strengthening exercises and to answer the following research questions: (a) Did lingual strength increase following 9 weeks of training? (b) Did training conducted using an exercise moving the tongue in one direction result in strength changes for tongue movements in

  15. Effects of Directional Exercise on Lingual Strength

    ERIC Educational Resources Information Center

    Clark, Heather M.; O'Brien, Katy; Calleja, Aimee; Corrie, Sarah Newcomb

    2009-01-01

    Purpose: To examine the application of known muscle training principles to tongue strengthening exercises and to answer the following research questions: (a) Did lingual strength increase following 9 weeks of training? (b) Did training conducted using an exercise moving the tongue in one direction result in strength changes for tongue movements in…

  16. ACL deficient potential copers and non-copers reveal different isokinetic quadriceps strength profiles in the early stage after injury

    PubMed Central

    Eitzen, I; Eitzen, TJ; Holm, I; Snyder-Mackler, L; Risberg, MA

    2011-01-01

    Background Isokinetic muscle strength tests using the peak torque value is the most frequently included quadriceps muscle strength measurement for anterior cruciate ligament (ACL) injured subjects. Aims The purpose of this study was to investigate quadriceps muscle performance during the whole isokinetic curve in ACL deficient subjects classified as potential copers or non-copers, and investigate whether these curve profiles were associated with single-leg hop performance. We hypothesized that quadriceps muscle torque at other knee flexion angles than peak torque would give more information about quadriceps muscle strength deficits. Furthermore, we hypothesized that there would be significant torque differences between potential copers and non-copers, and a significant relationship between angle specific torque values and single-leg hop performance. Study Design Cross-sectional study; Level of evidence, 2 Methods Seventy-six individuals with a complete unilateral ACL rupture within the last 3 months were included. The subjects were classified into potential copers and non-copers according to the criteria from Fitzgerald et al12. Isokinetic quadriceps muscle tests were performed at 60°/sec (Biodex 6000). Mean torque values were calculated for peak torque as well as for specific knee flexion angles. The one-leg hop and the 6 meter timed hop tests were included and symmetry indices were used. Results The peak torque value did not identify the largest quadriceps muscle strength deficit. Rather, these were established at knee flexion angles of less than 40°. There were significant differences in angle specific torque values between potential copers and non-copers (p<0.05). Moderate to strong associations were disclosed between angle specific torque values and single-leg hop performance, but only for non-copers (r≥0.32– 0.58). Conclusions Angle specific quadriceps muscle torque values of less than 40° of knee flexion provide more information on the quadriceps strength deficits after ACL injury compared to the commonly used peak torque values. PMID:20110458

  17. Relative Distribution of Quadriceps Head Anatomical Cross-Sectional Areas and Volumes – Sensitivity to Pain and to Training Intervention

    PubMed Central

    Sattler, M; Dannhauer, T; Ring-Dimitriou, S; Sänger, AM; Wirth, W; Hudelmaier, M; Eckstein, F

    2014-01-01

    SUMMARY Introduction Quadriceps heads are important in biomechanical stabilization and in the pathogenesis osteoarthritis of the knee. This is the first study to explore the relative distribution of quadriceps head anatomical cross-sectional areas (ACSA) and volumes, and their response to pain and to training intervention. Methods The relative proportions of quadriceps heads were determined in 48 Osteoarthritis Initiative participants with unilateral pain (65% women; age 45–78y). Quadriceps head volumes were also measured in 35 untrained women (45–55y) before and after 12 week training intervention. Cross-sectional areas of the vastus medialis (VM), inter-medius (VIM), and lateralis (VL), and of the rectus femoris (RF) were determined from axial T1-weighted MR images. Results The proportion of the VM on the total quadriceps ACSA increased from proximal to distal. The difference in quadriceps ACSA of painful (vs. pain-free) limbs was −5.4% for the VM (p<0.001), −6.8% for the VL (p<0.01), −2.8% for the VIM (p=0.06), and +3.4% for the RF (p=0.67) but the VM/VL ratio was not significantly altered. The muscle volume increase during training intervention was +4.2% (p<0.05) for VM, +1.3% for VL, +2.0% for VIM (p<0.05) and +1.6% for RF. Conclusion The proportion of quadriceps head relative to total muscle ACSA and volume depends on the anatomical level studied. The results suggest that there may be a differential response of the quadriceps heads to pain-induced atrophy and to training-related hypertrophy. Studies in larger samples are needed to ascertain whether the observed differences in response to pain and training are statistically and clinically significant. PMID:25153247

  18. Surgical management of acute quadriceps tendon rupture (a case report with literature review)

    PubMed Central

    Ennaciri, Badr; Montbarbon, Eric; Beaudouin, Emmanuel

    2015-01-01

    Quadriceps tendon rupture is uncommon and often overlooked in emergency. Tearing affects weakening tendon by systemic diseases or some medications. The mechanism is generally indirect. Inability to actively extend the knee associated to a supra-patellar defect evoke easily the diagnosis without other investigations. Surgical repair is realized in emergency to completely restore the extension. We report a case of a patient who has sustained of complete quadriceps tendon tear after a long period of tendon weakening by statin therapy, hypertension and diabetes. The repair has consisted on end-to-end Krackow sutures associated with bone suture to the proximal pole of the patella. Surgeons and emergency physicians must think to this form of extensor apparatus rupture, because early diagnosis leads to early treatment and to best outcomes.

  19. The role of muscle mass in exercise-induced hyperemia

    PubMed Central

    Groot, H. Jonathan; Rossman, Matthew J.; Gifford, Jayson R.; Richardson, Russell S.

    2014-01-01

    Exercise-induced hyperemia is often normalized for muscle mass, and this value is sometimes evaluated at relative exercise intensities to take muscle recruitment into account. Therefore, this study sought to better understand the impact of muscle mass on leg blood flow (LBF) during exercise. LBF was assessed by Doppler ultrasound in 27 young healthy male subjects performing knee-extensor (KE) exercise at three absolute (5, 15, and 25 W) and three relative [20, 40, and 60% of maximum KE (KEmax)] workloads. Thigh muscle mass (5.2–8.1 kg) and LBF were significantly correlated at rest (r = 0.54; P = 0.004). Exercise-induced hyperemia was linearly related to absolute workload, but revealed substantial between-subject variability, documented by the coefficient of variation (5 W: 17%; 15 W: 16%; 25 W: 16%). Quadriceps muscle mass (1.5–2.7 kg) and LBF were not correlated at 5, 15, or 25 W (r = 0.09–0.01; P = 0.7–0.9). Normalizing blood flow for quadriceps muscle mass did not improve the coefficient of variation at each absolute workload (5 W: 21%; 15 W: 21%; 25 W: 22%), while the additional evaluation at relative exercise intensities resulted in even greater variance (20% KEmax: 29%; 40% KEmax: 29%; 60% KEmax: 27%). Similar findings were documented when subjects were parsed into high and low aerobic capacity. Thus, in contrast to rest, blood flow during exercise is unrelated to muscle mass, and simply normalizing for muscle mass or comparing normalized blood flow at a given relative exercise intensity has no effect on the inherent blood flow variability. Therefore, during exercise, muscle mass does not appear to be a determinant of the hyperemic response. PMID:24674856

  20. Questionable Exercises.

    ERIC Educational Resources Information Center

    Liemohn, Wendell; Haydu, Traci; Phillips, Dawn

    1999-01-01

    This publication presents general guidelines for exercise prescription that have an anatomical basis but also consider the exerciser's ability to do the exercise correctly. It reviews various common questionable exercises, explaining how some exercises, especially those designed for flexibility and muscle fitness, can cause harm. Safer…

  1. Evaluation of Electromyographic Biofeedback for the Quadriceps Femoris: A Systematic Review

    PubMed Central

    Wasielewski, Noah J.; Parker, Tonya M.; Kotsko, Kevin M.

    2011-01-01

    Objective: To critically review evidence for the effectiveness of electromyographic biofeedback (EMGB) of the quadriceps femoris muscle in treating various knee conditions. Data Sources: Databases used to locate randomized controlled trials included PubMed (1980–2010), Cumulative Index of Nursing and Allied Health Literature (CINAHL, 1995–2007), Web of Science (1986–2010), SPORTDiscus (1990–2007), and Physiotherapy Evidence Database (PEDro). Key words were knee and biofeedback. Study Selection: The criteria for selection were clinical randomized controlled trials in which EMGB of the quadriceps femoris was used for various knee conditions of musculoskeletal origin. Trials were excluded because of research designs other than randomized controlled trials, articles published in a non-English language, inclusion of healthy research participants, inability to identify EMGB as the source of clinical improvement, and lack of pain, functional outcome, or quadriceps torque as outcome measures. Data Extraction: Twenty specific data points were abstracted from each clinical trial under the broad categories of attributes of the patient and injury, treatment variables for the EMGB group, treatment variables for the control group, and attributes of the research design. Data Synthesis: Eight trials yielded a total of 319 participants with patellofemoral pain syndrome (n = 86), anterior cruciate ligament reconstruction (n = 52), arthroscopic surgery (n = 91), or osteoarthritis (n = 90). The average methodologic score of the included studies was 4.6/10 based on PEDro criteria. Pooled analyses demonstrated heterogeneity of the included studies, rendering the interpretation of the pooled data inappropriate. The EMGB appeared to benefit short-term postsurgical pain or quadriceps strength in 3 of 4 postsurgical investigations but was ineffective for chronic knee conditions such as patellofemoral pain and osteoarthritis in all 4 studies. Because the findings are based on limited data, caution is warranted until more randomized controlled trials are conducted to support or refute the general trends observed in this report. PMID:22488142

  2. Quadriceps neural alterations in anterior cruciate ligament reconstructed patients: A 6-month longitudinal investigation.

    PubMed

    Lepley, A S; Gribble, P A; Thomas, A C; Tevald, M A; Sohn, D H; Pietrosimone, B G

    2015-12-01

    The purpose of this investigation was to evaluate differences in quadriceps corticospinal excitability, spinal-reflexive excitability, strength, and voluntary activation before, 2 weeks post and 6 months post-anterior cruciate ligament reconstruction (ACLr). This longitudinal, case-control investigation examined 20 patients scheduled for ACLr (11 females, 9 males; age: 20.9 ± 4.4 years; height:172.4 ± 7.5 cm; weight:76.2 ± 11.8 kg) and 20 healthy controls (11 females, 9 males; age:21.7 ± 3.7 years; height: 173.7 ± 9.9 cm; weight: 76.1 ± 19.7 kg). Maximal voluntary isometric contractions (MVIC), central activation ratio (CAR), normalized Hoffmann spinal reflexes, active motor threshold (AMT), and normalized motor-evoked potential (MEP) amplitudes at 120% of AMT were measured in the quadriceps muscle at the specific time points. ACLr patients demonstrated bilateral reductions in spinal-reflexive excitability compared with controls before surgery (P = 0.02) and 2 weeks post-surgery (P ≤ 0.001). ACLr patients demonstrated higher AMT at 6 months post-surgery (P ≤ 0.001) in both limbs. No MEP differences were detected. Quadriceps MVIC and CAR were lower in both limbs of the ACLr group before surgery and 6 months post-surgery (P ≤ 0.05) compared with controls. Diminished excitability of spinal-reflexive and corticospinal pathways are present at different times following ACLr and occur in combination with clinical deficits in quadriceps strength and activation. Early rehabilitation strategies targeting spinal-reflexive excitability may help improve postoperative outcomes, while later-stage rehabilitation may benefit from therapeutic techniques aimed at improving corticospinal excitability. PMID:25693627

  3. An in vivo rodent model of contraction-induced injury in the quadriceps muscle

    PubMed Central

    Pratt, Stephen J.P.; Lawlor, Michael W.; Shah, Sameer B.; Lovering, Richard M.

    2011-01-01

    Most animal studies of muscle contractile function utilize the anterior or posterior crural muscle (dorsiflexors and plantarflexors, respectively). An advantage to using these muscles is that the common fibular and tibial nerves are readily accessible, while the small size of the crural muscles is a disadvantage. Working with small muscles not only makes some in vivo imaging and the muscle testing techniques more challenging, but also provides limited amounts of tissue to study. The purpose of this study was to describe a new animal muscle injury model in the quadriceps that results in a significant and reproducible loss of force. The thigh of Sprague Dawley rats (N = 5) and C57BL/10 mice (N = 5) was immobilized and the ankle was attached to a custom-made lever arm. The femoral nerve was stimulated using subcutaneous electrodes and injury was induced using 50 lengthening (“eccentric”) contractions through a 70° arc of knee motion. This protocol produces a significant and reproducible injury, with comparable susceptibility to injury in the rats and mice. This novel model shows that the quadriceps muscle provides a means to study whole muscle contractility, injury, and recovery in vivo. In addition to the usual benefits of an in vivo model, the larger size of the quadriceps facilitates in vivo imaging and provides a significant increase in the amount of tissue available for histology and biochemistry studies. A controlled muscle injury in the quadriceps also allows one to study a muscle, with mixed fiber types, which is extremely relevant to gait in humans and quadruped models. PMID:22001505

  4. A dynamic warm-up model increases quadriceps strength and hamstring flexibility.

    PubMed

    Aguilar, Alain J; DiStefano, Lindsay J; Brown, Cathleen N; Herman, Daniel C; Guskiewicz, Kevin M; Padua, Darin A

    2012-04-01

    Research suggests that static stretching can negatively influence muscle strength and power and may result in decreased functional performance. The dynamic warm-up (DWU) is a common alternative to static stretching before physical activity, but there is limited research investigating the effects of a DWU. The purpose of this study was to compare the acute effects of a DWU and static stretching warm-up (SWU) on muscle flexibility, strength, and vertical jump using a randomized controlled trial design. Forty-five volunteers were randomly assigned into a control (CON), SWU, or DWU group. All participants rode a stationary bicycle for 5 minutes and completed a 10-minute warm-up protocol. During this protocol, the DWU group performed dynamic stretching and running, the SWU group performed static stretching, and the CON group rested. Dependent variables were measured immediately before and after the warm-up protocol. A digital inclinometer measured flexibility (degrees) for the hamstrings, quadriceps, and hip flexor muscles. An isokinetic dynamometer measured concentric and eccentric peak torque (N·m/kg) for the hamstrings and quadriceps. A force plate was used to measure vertical jump height (meters) and power (watts). In the DWU group, there was a significant increase in hamstring flexibility (pretest: 26.4 ± 13.5°, posttest: 16.9 ± 9.4°; p < .0001) and eccentric quadriceps peak torque (pretest: 2.49 ± 0.83 N·m/kg, posttest: 2.78 ± 0.69 N·m/kg; p = 0.04). The CON and SWU did not significantly affect any flexibility, strength, or vertical jump measures (p > 0.05). The DWU significantly improved eccentric quadriceps strength and hamstrings flexibility, whereas the SWU did not facilitate any positive or negative changes in muscle flexibility, strength, power, or vertical jump. Therefore, the DWU may be a better preactivity warm-up choice than an SWU. PMID:22446678

  5. Preserved function and reduced angiogenesis potential of the quadriceps in patients with mild COPD

    PubMed Central

    2014-01-01

    Background Little is known about limb muscle abnormalities in mild COPD. Inactivity and systemic inflammation could play a role in the development of limb muscle dysfunction in COPD. The objective of the present study was to characterize quadriceps function, enzymatic activities and morphometry, levels of plasma inflammatory markers and physical activity levels in daily life (PAdl) in patients with mild COPD (GOLD 1). Methods Mid-thigh muscle cross-sectional area (MTCSA), quadriceps strength, endurance, fiber-type distribution, capillarity, pro-angiogenesis factors (VEGF-A, angiopoietin I and II) and muscle oxidative capacity were assessed in 37 patients with mild COPD and 19 controls. Systemic inflammatory markers (CRP, IL-6, TNF-α, Fibrinogen, SP-D) and PAdl were assessed. Results MTCSA, quadriceps strength and endurance were not different between COPD and controls. Capillarity and muscle oxidative capacity were all preserved in mild COPD. Reduced pro-angiogenesis factor mRNA expression was seen in COPD. The level of moderately active intensity (>3 METs) was significantly lower in mild COPD and, in multiple regression analyses, the level of physical activity was a determinant of muscle oxidative capacity and capillarization. No between-group differences were found regarding muscle oxidative stress while circulating IL-6 levels were elevated in mild COPD. Conclusions The quadriceps muscle function was preserved in mild COPD although a reduced potential for angiogenesis was found. The reduced level of daily activities and evidence of systemic inflammation in these individuals suggest that these factors precede the development of overt limb muscle dysfunction in COPD. PMID:24438094

  6. In vivo patellar tracking induced by individual quadriceps components in individuals with patellofemoral pain

    PubMed Central

    Lin, Fang; Wilson, Nicole A.; Makhsous, Mohsen; Press, Joel M.; Koh, Jason L.; Nuber, Gordon W.; Zhang, Li-Qun

    2009-01-01

    Patellofemoral pain is a common knee disorders with a multi-factorial etiology related to abnormal patellar tracking. Our hypothesis was that the pattern of 3-dimensional rotation and translation of the patella induced by selective activation of individual quadriceps components would differ between subjects with patellofemoral pain and healthy subjects. Nine female subjects with patellofemoral pain and seven healthy female subjects underwent electrical stimulation to selectively activate individual quadriceps components (vastus medialis obliquus, VMO; vastus medialis lateralis, VML; vastus lateralis, VL) with the knee at 0° and 20° flexion, while three-dimensional patellar tracking was recorded. Normalized direction of rotation and direction of translation characterized the relative amplitudes of each component of patellar movement. VMO activation in patellofemoral pain caused greater medial patellar rotation (distal patellar pole rotates medially in frontal plane) at both knee positions (p<0.01), and both VMO and VML activation caused increased anterior patellar translation (p<0.001) in patellofemoral pain compared to healthy subjects at 20° knee flexion. VL activation caused more lateral patellar translation (p<0.001) in patellofemoral pain compared to healthy subjects. In healthy subjects the 3-D mechanical action of the VMO is actively modulated with knee flexion angle while such modulation was not observed in PFP subjects. This could be due to anatomical differences in the VMO insertion on the patella and medial quadriceps weakness. Quantitative evaluation of the influence of individual quadriceps components on patellar tracking will aid understanding of the knee extensor mechanism and provide insight into the etiology of patellofemoral pain. PMID:19878947

  7. Strengthening regional safeguards

    SciTech Connect

    Palhares, L.; Almeida, G.; Mafra, O.

    1996-08-01

    Nuclear cooperation between Argentina and Brazil has been growing since the early 1980`s and as it grew, so did cooperation with the US Department of Energy (DOE). The Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials (ABACC) was formed in December 1991 to operate the Common System of Accounting and Control of Nuclear Materials (SCCC). In April 1994, ABACC and the DOE signed an Agreement of Cooperation in nuclear material safeguards. This cooperation has included training safeguards inspectors, exchanging nuclear material measurement and containment and surveillance technology, characterizing reference materials, and studying enrichment plant safeguards. The goal of the collaboration is to exchange technology, evaluate new technology in Latin American nuclear facilities, and strengthen regional safeguards. This paper describes the history of the cooperation, its recent activities, and future projects. The cooperation is strongly supported by all three governments: the Republics of Argentina and Brazil and the United States.

  8. Exercising with a Muscle Disease

    MedlinePLUS

    ... strengthen- ing exercise, such as using a stretchable therapeutic band. … a 20-year-old male college student with McArdle disease? McArdle disease, which is caused by the lack of an enzyme that normally breaks down glycogen (animal starch) to generate energy in muscle cells, poses ...

  9. Isometric quadriceps strength determines sailing performance and neuromuscular fatigue during an upwind sailing emulation.

    PubMed

    Bourgois, Jan G; Callewaert, Margot; Celie, Bert; De Clercq, Dirk; Boone, Jan

    2016-05-01

    This study investigates the physiological responses to upwind sailing on a laser emulation ergometer and analyses the components of the physical profile that determine the physiological responses related to sailing level. Ten male high-level laser sailors performed an upwind sailing test, incremental cycling test and quadriceps strength test. During the upwind sailing test, heart rate (HR), oxygen uptake, ventilation, respiratory exchange ratio, rating of perceived exertion (RPE) and lactate concentration were measured, combined with near-infrared spectroscopy (NIRS) and electromyography (EMG) registration of the M. Vastus lateralis. Repeated measures ANOVA showed for the cardio-respiratory, metabolic and muscles responses (mean power frequency [MPF], root mean square [RMS], deoxy[Hb+Mb]) during the upwind sailing test an initial significant increase followed by a stabilisation, despite a constant increase in RPE. Stepwise regression analysis showed that better sailing level was for 46.5% predicted by lower MPF decrease. Lower MPF decrease was for 57.8% predicted by a higher maximal isometric quadriceps strength. In conclusion, this study indicates that higher sailing level was mainly determined by a lower rate of neuromuscular fatigue during the upwind sailing test (as indicated by MPF decrease). Additionally, the level of neuromuscular fatigue was mainly determined by higher maximal isometric quadriceps strength stressing the importance of resistance training in the planning of training. PMID:26323461

  10. An Acute Bout of Quadriceps Muscle Stretching has no Influence on Knee Joint Proprioception

    PubMed Central

    Torres, Rui; Duarte, José Alberto; Cabri, Jan MH

    2012-01-01

    The main objective of this study was to determine if an acute bout of static stretching of the quadriceps muscle affects the sense of joint position, the threshold to detect passive movement, and the sense of force. Thirty young, healthy men (age : 22.1 ± 2.7 years) were randomly divided into two groups. The Stretching Group (n=15) underwent stretching of the dominant quadriceps muscle, which comprised ten passive stretches lasting 30 seconds each, while the Control Group (n=15) remained seated for the same length of time. A repeated-measures analysis of variance was used to establish intragroup differences over time, and an independent sample t-test was used to compare the dependent variables between groups at each moment. None of the measurements revealed any significant change between both groups in each assessment moment or between moments within groups (p>0.05). This study demonstrated that static quadriceps muscle stretching has no effect on the sense of knee joint position, threshold to detect passive movement, and force sense, suggesting that stretching does not have appreciable effect on the spindle firing characteristics and tendon organs activation. PMID:23486744

  11. Ultrasound characteristics of the patellar and quadriceps tendons among young elite athletes.

    PubMed

    Visnes, H; Tegnander, A; Bahr, R

    2015-04-01

    Tendons adapt in response to sports-specific loading, but sometimes develop tendinopathy. If the presence of ultrasound changes like hypoechoic areas and neovascularization in asymptomatic tendons precede (and predict) future tendon problems is unknown. The aim of this prospective cohort study was to investigate the relationship between the development of ultrasound changes in the patellar and quadriceps tendons and symptoms of jumper's knee, as well to examine the medium-term effects of intensive training on tendon thickness among adolescent athletes. Elite junior volleyball athletes were followed with semi-annual ultrasound and clinical examinations (average follow-up: 1.7 years). Of the 141 asymptomatic athletes included, 22 athletes (35 patellar tendons) developed jumper's knee. In a multivariate logistic regression analysis, a baseline finding of a hypoechoic tendon area (odds ratio 3.3, 95% confidence interval 1.1 to 9.2) increased the risk of developing symptoms of jumper's knee. Patellar tendon thickness among healthy athletes did not change (Wilk's lambda, P = 0.07) while quadriceps tendon thickness increased (P = 0.001). In conclusion, ultrasound changes at baseline were risk factors for developing symptoms of jumper's knee. Also, among healthy athletes, we observed a 7-11% increase in quadriceps tendon thickness, while there was no increase in patellar tendon thickness. PMID:24612006

  12. Validity of the twitch interpolation technique for the assessment of quadriceps neuromuscular asymmetries.

    PubMed

    Maffiuletti, Nicola Angelo; Barbero, Marco; Cescon, Corrado; Clijsen, Ron; Beretta-Piccoli, Matteo; Schneebeli, Alessandro; Preiss, Stefan; Togninalli, Danilo

    2016-06-01

    This study examined the validity of the twitch interpolation technique for evaluating side-to-side asymmetries in quadriceps neuromuscular function. Fifty-six subjects with a wide range of asymmetries (19 healthy, 24 with unilateral and 13 with bilateral anterior cruciate ligament reconstruction) took part in the study. Supramaximal electrical paired stimuli were delivered to the quadriceps muscle during and immediately after a maximal voluntary contraction (MVC) of the knee extensors (twitch interpolation technique). MVC torque, voluntary activation and resting doublet-evoked torque were measured separately for the two sides, and percent side-to-side asymmetries were calculated for each parameter. MVC torque asymmetry was plotted against voluntary activation asymmetry and doublet-evoked torque asymmetry, and a multiple regression analysis was also conducted. Significant positive correlations were observed between MVC torque asymmetry and both voluntary activation asymmetry (r=0.40; p=0.002) and doublet-evoked torque asymmetry (r=0.53; p<0.001), and their relative contribution to MVC torque asymmetry was comparable (r=0.64; p<0.001). These results establish the validity of the twitch interpolation technique for the assessment of neuromuscular asymmetries. This methodology could provide useful insights into the contribution of some neural and muscular mechanisms that underlie quadriceps strength deficits. PMID:26990615

  13. Children as citizens and partners in strengthening communities.

    PubMed

    Smith, Anne B

    2010-01-01

    Children are citizens who are entitled to recognition, respect, and participation. Positioning children as citizens gives them the opportunity to play a role in solving fundamental problems and, in partnership with adults, strengthen their communities. Research on children's understanding of rights, responsibilities, and citizenship can build a platform for action. Numerous examples of projects are available in which children have been encouraged and supported to exercise their agency and put into practice the ideals of citizenship for the benefit of their communities. If children are to exercise their rights and responsibilities as citizens, change must occur in both adult and child cultures. PMID:20397994

  14. An Electromyographic Investigation of 4 Elastic-Tubing Closed Kinetic Chain Exercises After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Schulthies, Shane S.; Ricard, Mark D.; Alexander, Kimbie J.; Myrer, J. William

    1998-01-01

    Objective: To determine the electromyographic (EMG) activity of the vastus medialis oblique (VMO), vastus lateralis (VL), semitendinosus and semimembranosus (ST), and biceps femoris (BF) muscles during 4 elastic-tubing closed kinetic chain exercises in postoperative patients with anterior cruciate ligament (ACL)-reconstructed knees. Design and Setting: A 4 × 4 repeated-measures analysis of variance design guided this study. Independent variables were type of exercise and muscle; the dependent variable was EMG activity. Subjects: Fifteen patients, 5 to 24 weeks after ACL reconstruction. Measurements: Subjects performed 4 exercises (front pull, back pull, crossover, reverse crossover) with elastic tubing attached to the foot of the uninjured leg. Time-and amplitude- normalized EMG activity was recorded from the VMO, VL, ST, and BF muscles of the injured leg. The hamstrings: quadriceps ratio was calculated. Results: The normalized VMO, VL, and BF EMG activity ranged from 25% to 50% of maximum voluntary isometric contraction for the 4 exercises. The ST ranged from 12% on the back pull to 58% on the front pull. The hamstrings: quadriceps ratios were 137% (front pull), 115% (crossover), 70% (back pull), and 60% (reverse crossover). Conclusions: We suggest that clinicians use these exercises during early ACL rehabilitation since they incorporate early weightbearing with hamstring and quadriceps coactivation. ImagesFigure 1.Figure 2.Figure 3.Figure 4. PMID:16558530

  15. Mechanical, hormonal, and hypertrophic adaptations to 10 weeks of eccentric and stretch-shortening cycle exercise training in old males.

    PubMed

    Váczi, Márk; Nagy, Szilvia A; Kőszegi, Tamás; Ambrus, Míra; Bogner, Péter; Perlaki, Gábor; Orsi, Gergely; Tóth, Katalin; Hortobágyi, Tibor

    2014-10-01

    The growth promoting effects of eccentric (ECC) contractions are well documented but it is unknown if the rate of stretch per se plays a role in such muscular responses in healthy aging human skeletal muscle. We tested the hypothesis that exercise training of the quadriceps muscle with low rate ECC and high rate ECC contractions in the form of stretch-shortening cycles (SSCs) but at equal total mechanical work would produce rate-specific adaptations in healthy old males age 60-70. Both training programs produced similar improvements in maximal voluntary isometric (6%) and ECC torque (23%) and stretch-shortening cycle function (reduced contraction duration [24%] and enhanced elastic energy storage [12%]) (p<0.05). The rate of torque development increased 30% only after SSC exercise (p<0.05). Resting testosterone and cortisol levels were unchanged but after each program the acute exercise-induced cortisol levels were 12-15% lower (p<0.05). Both programs increased quadriceps size 2.5% (p<0.05). It is concluded that both ECC and SSC exercise training produces favorable adaptations in healthy old males' quadriceps muscle. Although the rate of muscle tension during the SSC vs. ECC contractions was about 4-fold greater, the total mechanical work seems to regulate the hypetrophic, hormonal, and most of the mechanical adaptations. However, SSC exercise was uniquely effective in improving a key deficiency of aging muscle, i.e., its ability to produce force rapidly. PMID:25064038

  16. The role of active muscle mass in determining the magnitude of peripheral fatigue during dynamic exercise

    PubMed Central

    Rossman, Matthew J.; Garten, Ryan S.; Venturelli, Massimo; Amann, Markus

    2014-01-01

    Greater peripheral quadriceps fatigue at the voluntary termination of single-leg knee-extensor exercise (KE), compared with whole-body cycling, has been attributed to confining group III and IV skeletal muscle afferent feedback to a small muscle mass, enabling the central nervous system (CNS) to tolerate greater peripheral fatigue. However, as task specificity and vastly differing systemic challenges may have complicated this interpretation, eight males were studied during constant workload trials to exhaustion at 85% of peak workload during single-leg and double-leg KE. It was hypothesized that because of the smaller muscle mass engaged during single-leg KE, a greater magnitude of peripheral quadriceps fatigue would be present at exhaustion. Vastus lateralis integrated electromyogram (iEMG) signal relative to the first minute of exercise, preexercise to postexercise maximal voluntary contractions (MVCs) of the quadriceps, and twitch-force evoked by supramaximal magnetic femoral nerve stimulation (Qtw,pot) quantified peripheral quadriceps fatigue. Trials performed with single-leg KE (8.1 ± 1.2 min; 45 ± 4 W) resulted in significantly greater peripheral quadriceps fatigue than double-leg KE (10 ± 1.3 min; 83 ± 7 W), as documented by changes in the iEMG signal (147 ± 24 vs. 85 ± 13%), MVC (−25 ± 3 vs. −12 ± 3%), and Qtw,pot (−44 ± 6 vs. −33 ± 7%), for single-leg and double-leg KE, respectively. Therefore, avoiding concerns over task specificity and cardiorespiratory limitations, this study reveals that a reduction in muscle mass permits the development of greater peripheral muscle fatigue and supports the concept that the CNS tolerates a greater magnitude of peripheral fatigue when the source of group III/IV afferent feedback is limited to a small muscle mass. PMID:24740653

  17. Exercise Prescription.

    ERIC Educational Resources Information Center

    Ribisl, Paul M.

    If exercise programs are to become effective in producing the desired results, then the correct exercise prescription must be applied. Four variables should be controlled in the prescription of exercise: (a) type of activity, (b) intensity, (c) duration, and (d) frequency. The long-term prescription of exercise involves the use of a (a) starter…

  18. Exercise-induced muscle glucose uptake in mice with graded, muscle-specific GLUT-4 deletion

    PubMed Central

    Howlett, Kirsten F; Andrikopoulos, Sofianos; Proietto, Joseph; Hargreaves, Mark

    2013-01-01

    To investigate the importance of the glucose transporter GLUT-4 for muscle glucose uptake during exercise, transgenic mice with skeletal muscle GLUT-4 expression approximately 30–60% of normal (CON) and approximately 5–10% of normal (KO) were generated using the Cre/Lox system and compared with wild-type (WT) mice during approximately 40 min of treadmill running (KO: 37.7 ± 1.3 min; WT: 40 min; CON: 40 min, P = 0.18). In WT and CON animals, exercise resulted in an overall increase in muscle glucose uptake. More specifically, glucose uptake was increased in red gastrocnemius of WT mice and in the soleus and red gastrocnemius of CON mice. In contrast, the exercise-induced increase in muscle glucose uptake in all muscles was completely abolished in KO mice. Muscle glucose uptake increased during exercise in both red and white quadriceps of WT mice, while the small increases in CON mice were not statistically significant. In KO mice, there was no change at all in quadriceps muscle glucose uptake. No differences in muscle glycogen use during exercise were observed between any of the groups. However, there was a significant increase in plasma glucose levels after exercise in KO mice. The results of this study demonstrated that a reduction in skeletal muscle GLUT-4 expression to approximately 10% of normal levels completely abolished the exercise-induced increase in muscle glucose uptake. PMID:24303141

  19. Regional variations in human patellar trabecular architecture and the structure of the quadriceps enthesis: a cadaveric study

    PubMed Central

    Toumi, Hechmi; Larguech, Gaith; Filaire, Edith; Pinti, Antonio; Lespessailles, Eric

    2012-01-01

    We investigated whether there were regional differences in the quadriceps enthesis and the patella bone structure that could suggest unequal force transmission to the patella. Quadriceps tendon enthesis was removed by cutting the patellae transversally in the middle and the quadriceps tendon approximately 1 cm from the bone. Tissues were post-fixed, decalcified, dehydrated through and embedded in paraffin wax. Serial longitudinal sections were cut, mounted on glass slides at 1-mm intervals and slides were stained. Trabecular architecture was analysed from digital images taken from the histological slides, and regional differences at the enthesis in the thickness of the uncalcified fibrocartilage and the cortical zone of calcified tissue (calcified cartilage and lamellar bone) were evaluated. At the quadriceps enthesis, the thickness of the cortical zone of calcified tissue was significantly greater in the central part of the enthesis than medially and laterally. The trabeculae were thicker in the central and lateral parts compared with the medial region. Similarly, the zone of uncalcified fibrocartilage was thicker laterally and centrally than medially. Bone structure and the thickness of uncalcified fibrocartilage presented a similarity between the centre and the lateral parts; however, the medial side was different. We suggest that the mechanical stress at the proximal quadriceps tendon enthesis is higher laterally and centrally compared with medially. This could induce a lateral patellar translation, which is potentially a risk factor for knee osteoarthritis. PMID:22458636

  20. Preactivation of the quadriceps muscle could limit cranial tibial translation in a cranial cruciate ligament deficient canine stifle.

    PubMed

    Ramirez, Juan M; Lefebvre, Michael; Böhme, Beatrice; Laurent, Cédric; Balligand, Marc

    2015-02-01

    Cranial cruciate ligament (CrCL) deficiency is the leading cause of lameness of the canine stifle. Application of tension in the quadriceps muscle could trigger cranial tibial translation in case of CrCL rupture. We replaced the quadriceps muscle and the gastrocnemius muscle by load cells and turn-buckles. First, eight canine limbs were placed in a servo-hydraulic testing machine, which applied 50% of body weight (BW). In a second phase, the CrCL was transected, and the limbs were tested in a similar manner. In a third phase, a quadriceps pretension of 15% BW was applied and limbs were again tested in a similar manner. Cranial tibial translation was significantly decreased in CrCL deficient stifles (p < 0.05) when quadriceps pretension was applied. These findings indicate that quadriceps pretension could play a role in the stability of a CrCL deficient stifle and should then be considered in rehabilitation programs and conservative treatment of CrCL rupture in dogs. PMID:25487559

  1. Effects of 4 weeks preoperative exercise on knee extensor strength after anterior cruciate ligament reconstruction.

    PubMed

    Kim, Do Kyung; Hwang, Ji Hye; Park, Won Hah

    2015-09-01

    [Purpose] After an anterior cruciate ligament injury and subsequent reconstruction, quadriceps muscle weakness and disruption of proprioceptive function are common. The purpose of this study was to examine the effects of a 4 weeks preoperative exercise intervention on knee strength power and function post-surgery. [Subjects and Methods] Eighty male patients (27.85.7 age), scheduled for reconstruction surgery, were randomly assigned to two groups, the preoperative exercise group (n=40) and a no preoperative exercise group (n=40). The preoperative exercise group participated in a 4-week preoperative and 12-week post-operative programs, while the no preoperative exercise group participated only in the 12-week postoperative exercise program. Isokinetic measured of quadriceps strength were obtained at 4 weeks before and 3 months after surgery. [Results] The knee extensor strength deficits measured at 60/s and 180/s was significantly lower in the preoperative exercise group compared with the no preoperative exercise group. At 3 months after surgery, the extensor strength deficit was 28.59.0% at 60/sec and 23.39.0% at 180/sec in the preoperative exercise group, whereas the no preoperative exercise group showed extensor strength deficits of 36.510.7% and 27.912.6% at 60/sec and 180/sec, respectively. The preoperative exercise group demonstrated significant improvement the single-leg hop distance. [Conclusion] Four week preoperative exercise may produce many positive effects post reconstruction surgery, including faster recovery of knee extensor strength and function, as measured by single-leg hop ability. PMID:26504270

  2. Effects of 4 weeks preoperative exercise on knee extensor strength after anterior cruciate ligament reconstruction

    PubMed Central

    Kim, Do Kyung; Hwang, Ji Hye; Park, Won Hah

    2015-01-01

    [Purpose] After an anterior cruciate ligament injury and subsequent reconstruction, quadriceps muscle weakness and disruption of proprioceptive function are common. The purpose of this study was to examine the effects of a 4 weeks preoperative exercise intervention on knee strength power and function post-surgery. [Subjects and Methods] Eighty male patients (27.8±5.7 age), scheduled for reconstruction surgery, were randomly assigned to two groups, the preoperative exercise group (n=40) and a no preoperative exercise group (n=40). The preoperative exercise group participated in a 4-week preoperative and 12-week post-operative programs, while the no preoperative exercise group participated only in the 12-week postoperative exercise program. Isokinetic measured of quadriceps strength were obtained at 4 weeks before and 3 months after surgery. [Results] The knee extensor strength deficits measured at 60°/s and 180°/s was significantly lower in the preoperative exercise group compared with the no preoperative exercise group. At 3 months after surgery, the extensor strength deficit was 28.5±9.0% at 60°/sec and 23.3±9.0% at 180°/sec in the preoperative exercise group, whereas the no preoperative exercise group showed extensor strength deficits of 36.5±10.7% and 27.9±12.6% at 60°/sec and 180°/sec, respectively. The preoperative exercise group demonstrated significant improvement the single-leg hop distance. [Conclusion] Four week preoperative exercise may produce many positive effects post reconstruction surgery, including faster recovery of knee extensor strength and function, as measured by single-leg hop ability. PMID:26504270

  3. Age-related changes in neuromuscular function of the quadriceps muscle in physically active adults.

    PubMed

    Mau-Moeller, Anett; Behrens, Martin; Lindner, Tobias; Bader, Rainer; Bruhn, Sven

    2013-06-01

    Substantial evidence exists for the age-related decline in maximal strength and strength development. Despite the importance of knee extensor strength for physical function and mobility in the elderly, studies focusing on the underlying neuromuscular mechanisms of the quadriceps muscle weakness are limited. The aim of this study was to investigate the contributions of age-related neural and muscular changes in the quadriceps muscle to decreases in isometric maximal voluntary torque (iMVT) and explosive voluntary strength. The interpolated twitch technique and normalized surface electromyography (EMG) signal during iMVT were analyzed to assess changes in neural drive to the muscles of 15 young and 15 elderly volunteers. The maximal rate of torque development as well as rate of torque development, impulse and neuromuscular activation in the early phase of contraction were determined. Spinal excitability was estimated using the H reflex technique. Changes at the muscle level were evaluated by analyzing the contractile properties and lean mass. The age-related decrease in iMVT was accompanied by a decline in voluntary activation and normalized surface EMG amplitude. Mechanical parameters of explosive voluntary strength were reduced while the corresponding muscle activation remained primarily unchanged. The spinal excitability of the vastus medialis was not different while M wave latency was longer. Contractile properties and lean mass were reduced. In conclusion, the age-related decline in iMVT of the quadriceps muscle might be due to a reduced neural drive and changes in skeletal muscle properties. The decrease in explosive voluntary strength seemed to be more affected by muscular than by neural changes. PMID:23453325

  4. Knee Extension Strength and Hamstrings-to-Quadriceps Imbalances in Elite Soccer Players.

    PubMed

    Bogdanis, G C; Kalapotharakos, V I

    2016-02-01

    This study examined the relationship between hamstrings-to-quadriceps strength ratio (H:Q) and relative strength of the knee extensors in elite soccer players. Peak torque was measured during isokinetic knee extension/flexion at angular velocities of 60°·s(-1), 180°·s(-1) and 300°·s(-1). 18 professional players were divided into 2 groups, depending on their H:Q at 60°·s(-1). Players in the lower H:Q group (n=7) had significantly smaller H:Q ratios compared with the higher H:Q group (n=11) at all angular velocities (60°·s(-1): 49.2%; 95% CI: 61.3-57.8% vs. 59.5%; 95% CI: 52.2-46.2%, p=0.001). Players in the lower H:Q group had greater knee-extension peak torque compared with the higher H:Q group (60°·s(-1): 313; 95% CI: 335-291 vs. 269; 95% CI: 289-250 N·m, p=0.01). No differences were found in hamstrings' strength between the 2 groups (60°·s(-1): 156; 95% CI: 170-143 vs. 160; 95% CI: 173-148 N·m, p=0.96). Negative correlations between knee extension peak torque and H:Q ratio were observed at all angular velocities (r=-0.65 to -0.67, p<0.01). In conclusion, a low H:Q strength ratio measured during isokinetic strength testing in professional soccer players, is observed mainly in those with strong quadriceps muscles, while players with lower quadriceps strength have H:Q ratios around the recommended values. PMID:26509377

  5. Effects of loaded voluntary wheel exercise on performance and muscle hypertrophy in young and old male C57Bl/6J mice.

    PubMed

    Soffe, Z; Radley-Crabb, H G; McMahon, C; Grounds, M D; Shavlakadze, T

    2016-02-01

    This study compared the capacity of young and old male C57Bl/6J mice to exercise with increasing resistance over 10 weeks, and its impact on muscle mass. Young mice (aged 15-25 weeks) were subjected to low (LR) and high (HR) resistance exercise, whereas only LR was used for old mice (107-117 weeks). Weekly patterns of voluntary wheel activity, food consumption and body weights were measured. Running patterns changed over time and with age, with two peaks of activity detected for young, but only one for old mice: speed and distance run was also less for old mice. The mass for six limb muscles was measured at the end of the experiment. The most pronounced increase in mass in response to exercise was for the soleus in young and old mice, and also quadriceps and gastrocnemius in young mice. Soleus and quadriceps muscles were analyzed histologically for myofiber number and size. A striking feature was the many small myofibers in response to exercise in young (but not old) soleus, whereas these were not present after exercise in young or old quadriceps. Overall, there was a striking difference in response to exercise between muscles and this was influenced by age. PMID:25653015

  6. Bedside Assessment of Quadriceps Muscle by Ultrasound after Admission for Acute Exacerbations of Chronic Respiratory Disease

    PubMed Central

    Harvey-Dunstan, Theresa C.; Chaplin, Emma J.; Vincent, Emma E.; Morgan, Mike D.; Singh, Sally J.; Steiner, Michael C.

    2015-01-01

    Rationale: Hospitalization represents a major event for the patient with chronic respiratory disease. There is a high risk of readmission, which over the longer term may be related more closely to the underlying condition of the patient, such as skeletal muscle dysfunction. Objectives: We assessed the risk of hospital readmission at 1 year, including measures of lower limb muscle as part of a larger clinical trial. Methods: Patients hospitalized with an exacerbation of chronic respiratory disease underwent measures of muscle function including quadriceps ultrasound. Independent factors influencing time to hospital readmission or death were identified. Patients were classified into four quartiles based on quadriceps size and compared. Measurements and Main Results: One hundred and ninety-one patients (mean age, 71.6 [SD, 9.1] yr) were recruited. One hundred and thirty (68%) were either readmitted or died. Factors associated with readmission or death were age (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01–1.08; P = 0.015), Medical Research Council (MRC) dyspnea grade (OR, 4.57; 95% CI, 2.62–7.95; P < 0.001), home oxygen use (OR, 12.4; 95% CI, 4.53–33.77; P < 0.001), quadriceps (rectus femoris) cross-sectional area (Qcsa) (OR, 0.34; 95% CI, 0.17–0.65; P = 0.001), and hospitalization in the previous year (OR, 4.82; 95% CI, 2.42–9.58; P < 0.001). In the multivariate analyses, home oxygen use (OR, 4.80; 95% CI, 1.68–13.69; P = 0.003), MRC dyspnea grade (OR, 2.57; 95% CI, 1.44–4.59; P = 0.001), Qcsa (OR, 0.46; 95% CI, 0.22–0.95; P = 0.035), and previous hospitalization (OR, 3.04; 95% CI, 1.47–6.29; P = 0.003) were independently associated with readmission or death. Patients with the smallest muscle spent more days in hospital than those with largest muscle (28.1 [SD, 33.9] vs. 12.2 [SD, 23.5] d; P = 0.007). Conclusions: Smaller quadriceps muscle size, as measured by ultrasound in the acute care setting, is an independent risk factor for unscheduled readmission or death, which may have value both in clinical practice and for risk stratification. PMID:26068143

  7. Gender-based analysis of hamstring and quadriceps muscle activation during jump landings and cutting.

    PubMed

    Ebben, William P; Fauth, McKenzie L; Petushek, Erich J; Garceau, Luke R; Hsu, Brittni E; Lutsch, Brittney N; Feldmann, Christina R

    2010-02-01

    This study evaluated gender differences in the magnitude and timing of hamstring and quadriceps activation during activities that are believed to cause anterior cruciate ligament (ACL) injuries. Twelve men (age = 21.0 +/- 1.2 years; body mass = 81.61 +/- 13.3 kg; and jump height = 57.61 +/- 10.15 cm) and 12 women (age = 19.91 +/- 0.9 years; body mass = 64.36 +/- 6.14 kg; and jump height = 43.28 +/- 7.5) performed 3 repetitions each of the drop jump (jump) normalized to the subject's vertical jump height, and a sprint and cut at a 45-degree angle (cut). Electromyography (EMG) was used to quantify rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), lateral hamstring (LH), and medial hamstrings (MH) activation, timing, activation ratios, and timing ratios before and after foot contact for the jump and cut and normalized to each subject's hamstring and quadriceps maximum voluntary isometric contraction. Data were analyzed using an analysis of variance with results demonstrating that during the postcontact phase of the cut, men demonstrated greater LH and MH activation than women. In the precontact phase of the jump, men showed earlier activation of the VL and VM, than women. Women produced longer RF and VM muscle bursts during the postcontact phase of the cut. Additionally, men showed a trend toward higher hamstring to quadriceps activation ratio than women for the postcontact phase of the cut. This study provides evidence that men are LH dominant during the postcontact phase of the cut compared with women, whereas women sustain RF activation longer than men during this phase. Men activate quadriceps muscles earlier than women in the precontact phase of the jump. Training interventions may offer the potential for increasing the rate and magnitude of hamstring muscle activation. These outcomes should be evaluated using EMG during movements that are similar to those that cause ACL injuries to determine if gender differences in muscle activation can be reduced. PMID:20124793

  8. Effects of Motorized vs Non-Motorized Treadmill Training on Hamstring/Quadriceps Strength Ratios

    PubMed Central

    Franks, Kelly A.; Brown, Lee E.; Coburn, Jared W.; Kersey, Robert D.; Bottaro, Martim

    2012-01-01

    Previous literature suggests that muscular involvement and biomechanical changes elicit different responses between overground and treadmill training. The objective of this study was to examine the effects of training on two different treadmill designs on the conventional (CR; concentric only) and functional (FR; eccentric to concentric) hamstring and quadriceps strength ratios. Fifteen men and sixteen women were randomly divided into three groups: motorized (MT), non-motorized (NMT) or control (C). Subjects completed pre and post-test isokinetic concentric and eccentric quadriceps and hamstring testing of both legs. Subjects completed 4 weeks of training on their respective treadmills with mileage increasing ½ mile each week, beginning with 2 miles. The C group did not participate in any training. The CR revealed a significant two way interaction of group x time with MT increasing (pre: 0.80 ± 0.09 to post: 0.84 ± 0.09), NMT decreasing (pre: 0.76 ± 0.13 to post: 0.74 ± 0.10), and C showing no change (pre: 0.79 ± 0.10 to post: 0.79 ± 0.09. The FR revealed a significant two way interaction of speed x sex with the FR increasing as speeds increased for men (60 degrees.s-1: 1.04 ± 0.11; 180 degrees.s-1: 1.66 ± 0.27; 300 degrees.s-1: 2.36 ± 0.45) and women (60 degrees.s-1: 1.05 ± 0.16; 180 degrees.s-1: 1.90 ± 0.26; 300 degrees.s-1: 2.75 ± 0.47) but women increased greater relative to men. Training mode elicited a specific change in concentric hamstring and quadriceps strength resulting in specific changes to the CR; however, neither training mode had an effect on eccentric hamstrings nor the FR. Special attention should be given to the mode of endurance training when the goal is to alter the hamstring/quadriceps CR. Key points Specificity of treadmill training had different effects on concentric strength. Specificity of treadmill training had little or no effect on eccentric strength. Conventional and functional strength ratios may give different results based on training mode. Four weeks is long enough for strength results to be apparent in untrained people. PMID:24137064

  9. Quadriceps traumatic myositis ossificans in a football player: management with intravenous pamidronate.

    PubMed

    Mani-Babu, Sivanadian; Wolman, Roger; Keen, Richard

    2014-09-01

    Myositis ossificans (MO) can be a significant complication of traumatic muscle contusion. Bisphosphates have been used in management of heterotopic ossification after spinal cord injury, but there is a lack of evidence with respect to MO in the sporting population. We present a case of a 14-year-old male football player with posttraumatic quadriceps MO, treated with 2 doses of intravenous pamidronate. This was associated with improvement in clinical features and imaging and a reduced urinary N-terminal telopeptide, a marker of bone turnover. This case demonstrates that bisphosphonates may be a potential treatment option in MO. PMID:24184852

  10. Local Pain Dynamics during Constant Exhaustive Exercise

    PubMed Central

    Hristovski, Robert; Tenenbaum, Gershon

    2015-01-01

    The purpose of this study was to delineate the topological dynamics of pain and discomfort during constant exercise performed until volitional exhaustion. Eleven physical education students were tested while cycling and running at a “hard” intensity level (e.g., corresponding to Borg’s RPE (6–20) = 15). During the tests, participants reported their discomfort and pain on a body map every 15s. “Time on task” for each participant was divided into five equal non-overlapping temporal windows within which their ratings were considered for analysis. The analyses revealed that the number of body locations with perceived pain and discomfort increased throughout the five temporal windows until reaching the mean (± SE) values of 4.2 ± 0.7 and 4.1 ± 0.6 in cycling and running, respectively. The dominant locations included the quadriceps and hamstrings during cycling and quadriceps and chest during running. In conclusion, pain seemed to spread throughout the body during constant cycling and running performed up to volitional exhaustion with differences between cycling and running in the upper body but not in the lower body dynamics. PMID:26421436

  11. Application of quantitative and progressive exercise rehabilitation to patients with osteoarthritis of the knee.

    PubMed

    Fisher, N M; Pendergast, D R

    1995-01-01

    Osteoarthritis (OA) is one of the most prevalent and disabling diseases in the elderly, a rapidly growing segment of the population. OA is typically treated with a combination of drugs and inactivity, with total joint arthroplasty as the final treatment alternative. This paper reviews the potential of a non-surgical intervention for patients with OA, namely exercise rehabilitation. Several types of exercise rehabilitation are considered: home exercise (HE), physical therapy (PT), cycle exercise (CE) and a new program, quantitative progressive exercise rehabilitation (QPER). The HE program demonstrated improvements in some physiological and functional variables; however, these improvements were minimal. PT had a greater effect than HE on quadriceps and hamstring muscle strength and endurance and functional performance; however, PT had no effect on muscle contraction speed. The QPER program improved motor unit activation, quadriceps and hamstring muscle strength and endurance, contraction speed and all aspects of functional performance. In addition, QPER, although not aerobic, improved cardiorespiratory fitness and maximal workrate of VO2. This program significantly reduced difficulty, dependency and pain (during rest, exercise and at night). It would appear that the therapy of choice would be QPER since it reduces symptoms, improves joint integrity and may lead to delays in arthroplasty. These changes could improve the quality of life of patients with OA, as well as other diseases, and reduce medical costs. PMID:24572159

  12. Electrical stimulation of quadriceps femoris in an elite weight lifter: a single subject experiment.

    PubMed

    Delitto, A; Brown, M; Strube, M J; Rose, S J; Lehman, R C

    1989-06-01

    The response to treatment of high intensity neuromuscular electrical stimulation (NMES) to both quadriceps femoris muscles as an adjunct to ongoing weight training was evaluated using a single subject experimental design. For an elite weight lifter weekly maximal measurements of snatch (S), clean and jerk (CJ), and front squat (SQ) were obtained over 4 months during which the subject weight trained daily for 3 h. The 1st month, baseline data were collected. After baseline measurements, a 1-month period of high-intensity NMES was added to the subject's weight training. NMES was then withdrawn for 1 month and administered once more for 2 weeks. Three quadriceps femoris muscle biopsies were taken, two during the initial baseline period and one just before the end of the first stimulation period. The results showed a significant and clear relationship between performance gains and NMES administration and withdrawal. Steep gains for S, CJ, and SQ were seen after 2 weeks of stimulation, with front squat showing a 20-kg increase within the 1st week of both stimulation periods. Muscle biopsy showed an increased type I fiber area, decreased type IIa and IIb fiber area, and an increase of type II fibers after NMES. The results of this study support the use of high-dose NMES as an adjunct to weight training in elite lifters. PMID:2674035

  13. A stepwise procedure to test contractility and susceptibility to injury for the rodent quadriceps muscle

    PubMed Central

    Pratt, Stephen J.P.; Lovering, Richard M.

    2014-01-01

    In patients with muscle injury or muscle disease, assessment of muscle damage is typically limited to clinical signs, such as tenderness, strength, range of motion, and more recently, imaging studies. Biological markers can also be used in measuring muscle injury, such as increased creatine kinase levels in the blood, but these are not always correlated with loss in muscle function (i.e. loss of force production). This is even true of histological findings from animals, which provide a “direct measure” of damage, but do not account for loss of function. The most comprehensive measure of the overall health of the muscle is contractile force. To date, animal models testing contractile force have been limited to the muscle groups moving the ankle. Here we describe an in vivo animal model for the quadriceps, with abilities to measure torque, produce a reliable muscle injury, and follow muscle recovery within the same animal over time. We also describe a second model used for direct measurement of force from an isolated quadriceps muscle in situ. PMID:25530979

  14. Measurement of the quadriceps femoris muscle using magnetic resonance and ultrasound imaging.

    PubMed Central

    Walton, J M; Roberts, N; Whitehouse, G H

    1997-01-01

    OBJECTIVES: To define a method for measurement of the cross sectional area and volume of the quadriceps femoris muscle using magnetic resonance imaging (MRI) in conjunction with stereology, and to compare the results of measurements obtained by the MRI method with those obtained by the conventional method of static B-mode ultrasound in order to evaluate whether MRI is a reliable alternative to ultrasound. METHODS: A preliminary MRI study was undertaken on a single female volunteer in order to optimise the scanning technique and sampling design for estimating the muscle volume using the Cavalieri method. Ten healthy volunteers participated in the method comparison study. Each volunteer underwent static B-mode ultrasonography, immediately followed by MRI. The cross sectional area of the quadriceps femoris was estimated at the junction of the proximal one third and distal two thirds of the thigh, and seven systematic sections of the thigh were obtained in order to estimate muscle volume by both modalities. RESULTS: Seven sections through the muscle are required to achieve a coefficient of error of 4-5%. There was no significant difference in the cross sectional area estimates or volume estimates when ultrasound and MRI were compared. CONCLUSION: Muscle cross sectional area and volume can be measured without bias by MRI in conjunction with stereological methods and the method is a reliable alternative to static B-mode ultrasound for this purpose. Images Figure 1 Figure 4 Figure 5 PMID:9132215

  15. [Quadriceps tendon insufficiency and rupture : Treatment options in total knee arthroplasty].

    PubMed

    Thiele, K; von Roth, P; Pfitzner, T; Preininger, B; Perka, C

    2016-05-01

    Quadriceps tendon injuries and insufficiencies in total knee arthroplasty are rare, but are followed by a devastating complication that left untreated leads to a complete loss of function of the knee. This review article summarizes the functional anatomy, risk factors, and the prevalence and diagnosis of quadriceps tendon injuries, in addition to the possible management options for partial and complete ruptures. The treatment options are adapted according to the extent of the loss of function (partial, complete) and the duration of the injury (acute vs chronic). Furthermore, the choice of treatment should take into account the quality and availability of primary tissue, the patient's general health, along with their likely functional requirements. Conservative treatment is often justified in partial ruptures with good results. Complete ruptures require surgical intervention and multiple operative techniques are described. Treatment options for acute ruptures include direct primary repair with autogenous or synthetic tissue augmentation. In the case of chronic insufficiency and a lack of soft-tissue surroundings, reconstruction with the aid of a muscle flap or allograft tissue can be considered. All surgical intervention techniques used so far have been fraught with complications and rarely lead to satisfactory results. A new surgical approach to the reconstruction and augmentation of the extensor mechanism consists of the use of a synthetic mesh. The technique is described here in detail. PMID:27125235

  16. Pro- and Anticonvulsant Effects of the Ant Dinoponera quadriceps (Kempf) Venom in Mice.

    PubMed

    Nôga, D A M F; Cagni, F C; Santos, J R; Silva, D; Azevedo, D L O; Araújo, A; Silva, R H; Ribeiro, A M

    2015-08-01

    Epilepsy affects at least 50 million people worldwide, and the available treatment is associated with various side effects. Approximately 20-30% of the patients develop seizures that persist despite careful monitored treatment with antiepileptic drugs. Thus, there is a clear need for the development of new antiepileptic drugs, and the venoms can be an excellent source of probes. In this context, while there are studies on venoms from snakes, scorpions, and spiders, little is known regarding venom from ants. The aim of this study was to investigate the potential pro- and anticonvulsant effects of the venom from the ant Dinoponera quadriceps (Kempf) in Swiss mice. After the injection of the crude venom (DqTx-5, 50, and 500 mg/mL) in the lateral ventricle of mice, we observed a reduction of exploration and grooming behaviors, as well as an increase in immobility duration. In addition, the crude venom induced procursive behavior and tonic-clonic seizures at the highest concentration. Conversely, the preadministration of the denatured venom (AbDq) at the concentration of 2 mg/mL protected the animals against tonic-clonic seizures (66.7%) and death (100%) induced by administration of bicuculline. Taken together, the findings demonstrate that D. quadriceps venom might be potential source of new pro- and anticonvulsants molecules. PMID:26045053

  17. Effective therapy of transected quadriceps muscle in rat: Gastric pentadecapeptide BPC 157.

    PubMed

    Staresinic, Mario; Petrovic, Igor; Novinscak, Tomislav; Jukic, Ivana; Pevec, Damira; Suknaic, Slaven; Kokic, Neven; Batelja, Lovorka; Brcic, Luka; Boban-Blagaic, Alenka; Zoric, Zdenka; Ivanovic, Domagoj; Ajduk, Marko; Sebecic, Bozidar; Patrlj, Leonardo; Sosa, Tomislav; Buljat, Gojko; Anic, Tomislav; Seiwerth, Sven; Sikiric, Predrag

    2006-05-01

    We report complete transection of major muscle and the systemic peptide treatment that induces healing of quadriceps muscle promptly and then maintains the healing with functional restoration. Initially, stable gastric pentadecapeptide BPC 157 (GEPPPGKPADDAGLV, M.W. 1419, PL-10, PLD-116, PL 14736 Pliva, Croatia; in trials for inflammatory bowel disease; wound treatment; no toxicity reported; effective alone without carrier) also superiorly accelerates the healing of transected Achilles tendon. Regularly, quadriceps muscle completely transected transversely 1.0 cm proximal to patella presents a definitive defect that cannot be compensated in rat. BPC 157 (10 microg, 10 ng, 10 pg/kg) is given intraperitoneally, once daily; the first application 30 min posttransection, the final 24 h before sacrifice. It consistently improves muscle healing throughout the whole 72-day period. Improved are: (i) biomechanic (load of failure increased); (ii) function (walking recovery and extensor postural thrust/motor function index returned toward normal healthy values); (iii) microscopy/immunochemistry [i.e., mostly muscle fibers connect muscle segments; absent gap; significant desmin positivity for ongoing regeneration of muscle; larger myofibril diameters on both sides, distal and proximal (normal healthy rat-values reached)]; (iv) macroscopic presentation (stumps connected; subsequently, atrophy markedly attenuated; finally, presentation close to normal noninjured muscle, no postsurgery leg contracture). Thus, posttransection healing-consistently improved-may suggest this peptide therapeutic application in muscle disorders. PMID:16609979

  18. Is quadriceps muscle strength a determinant of the physical function of the elderly?

    PubMed Central

    Altubasi, Ibrahim Mustafa

    2015-01-01

    [Purpose] To determine the relationships of the quadriceps rate of torque development and the time to peak torque with the physical function of the elderly. [Subjects and Methods] Twenty-one subjects participated in this study. Quadriceps strength was measured using isometric and isokinetic torque tests. Time to peak torque and rate of torque development were calculated from the torque time curve of the isokinetic and isometric torque tests, respectively. Physical activities were measured using 4 physical activity tests. Pearson correlation coefficients were used to examine the relationships among the variables. [Results] The time to peak torque showed significant correlations with all measures of physical activity tests. Rate of torque development showed significant correlation with the timed stair-climbing test. Isometric and isokinetic torques had no significant correlations with any of the physical activity tests. [Conclusion] Time to maximum torque and the rate of torque development might be more important than peak torque in determining the physical function of the elderly. PMID:26644638

  19. Compulsive Exercise

    MedlinePLUS

    ... overdoing it for almost anyone. Much like with eating disorders, many people who engage in compulsive exercise do ... compulsive exercising doesn't have to accompany an eating disorder, the two often go hand in hand. In ...

  20. Compulsive Exercise

    MedlinePLUS

    ... exercise, especially when it is combined with an eating disorder, can cause serious and permanent health problems, and in extreme cases, death. Because compulsive exercise is closely related to eating disorders, help can be found at community agencies specifically ...

  1. Vascular Occlusion and Sequential Compression for Recovery After Resistance Exercise.

    PubMed

    Northey, Joseph M; Rattray, Ben; Argus, Christos K; Etxebarria, Naroa; Driller, Matthew W

    2016-02-01

    Northey, JM, Rattray, B, Argus, CK, Etxebarria, N, and Driller, MW. Vascular occlusion and sequential compression for recovery after resistance exercise. J Strength Cond Res 30(2): 533-539, 2016-The purpose of this study was to evaluate vascular occlusion (OCC) and sequential intermittent pneumatic compression (SIPC) as recovery strategies after fatiguing resistance exercise. Twelve strength-trained male participants (age: 24.0 ± 6.3 years, height: 180.4 ± 9.7 cm, and weight: 84.8 ± 9.6 kg) participated in a randomized cross-over study. Participants performed a fatiguing resistance exercise bout consisting of 10 sets with 10 repetitions of back squats at 70% 1 repetition maximum with 3-minute rest between sets. Outcome measures of perceived recovery status, muscle soreness, concentric peak isokinetic torque of the quadriceps, squat jump (SJ) height, and countermovement jump (CMJ) height were taken before the fatiguing resistance exercise bout and repeated immediately post, 1 hour, and 24 hours later. Immediately after the postexercise measures, participants undertook 1 of the 3 recovery strategies: OCC, SIPC, and a passive control (CON). Concentric peak isokinetic torque of the quadriceps was decreased significantly immediately post and 1 hour after the fatiguing resistance exercise bout compared with baseline values (p ≤ 0.05). Mean SJ and CMJ jump height decreased significantly immediately post and 1 hour compared with baseline measures, but only the SJ was significantly decreased at 24 hours. There were no significant differences between conditions for any of the postexercise measures (p > 0.05). In conclusion, this study indicates that OCC and SIPC are not effective for attenuating muscle performance loss after a fatiguing resistance exercise bout relative to passive recovery. PMID:26154154

  2. Treadmill training increases SIRT-1 and PGC-1 ? protein levels and AMPK phosphorylation in quadriceps of middle-aged rats in an intensity-dependent manner.

    PubMed

    Oliveira, Nara R C; Marques, Scherolin O; Luciano, Thais F; Pauli, Jos R; Moura, Leandro P; Caperuto, Erico; Pieri, Bruno L S; Engelmann, Julia; Scaini, Gisele; Streck, Emilio L; Lira, Fabio S; Pinho, Ricardo A; Ropelle, Eduardo R; Silva, Adelino S R; De Souza, Cludio T

    2014-01-01

    The present study investigated the effects of running at 0.8 or 1.2 km/h on inflammatory proteins (i.e., protein levels of TNF- ? , IL-1 ? , and NF- ? B) and metabolic proteins (i.e., protein levels of SIRT-1 and PGC-1 ? , and AMPK phosphorylation) in quadriceps of rats. Male Wistar rats at 3 (young) and 18 months (middle-aged rats) of age were divided into nonexercised (NE) and exercised at 0.8 or 1.2 km/h. The rats were trained on treadmill, 50 min per day, 5 days per week, during 8 weeks. Forty-eight hours after the last training session, muscles were removed, homogenized, and analyzed using biochemical and western blot techniques. Our results showed that: (a) running at 0.8 km/h decreased the inflammatory proteins and increased the metabolic proteins compared with NE rats; (b) these responses were lower for the inflammatory proteins and higher for the metabolic proteins in young rats compared with middle-aged rats; (c) running at 1.2 km/h decreased the inflammatory proteins and increased the metabolic proteins compared with 0.8 km/h; (d) these responses were similar between young and middle-aged rats when trained at 1.2 km. In summary, the age-related increases in inflammatory proteins, and the age-related declines in metabolic proteins can be reversed and largely improved by treadmill training. PMID:25002755

  3. Morning Exercise

    ERIC Educational Resources Information Center

    Schmitt, Natalie Crohn

    2006-01-01

    In this article, Natalie Schmitt recalls her teaching experiences with morning exercise programs, beginning with her first teaching job as assistant Morning Exercise teacher at the Francis W. Parker School in Chicago. In the Morning Exercises, students were encouraged to employ all means of expression: speaking, drawing, dancing, singing, acting.…

  4. Morning Exercise

    ERIC Educational Resources Information Center

    Schmitt, Natalie Crohn

    2006-01-01

    In this article, Natalie Schmitt recalls her teaching experiences with morning exercise programs, beginning with her first teaching job as assistant Morning Exercise teacher at the Francis W. Parker School in Chicago. In the Morning Exercises, students were encouraged to employ all means of expression: speaking, drawing, dancing, singing, acting.

  5. Group III and IV muscle afferents contribute to ventilatory and cardiovascular response to rhythmic exercise in humans

    PubMed Central

    Blain, Gregory M.; Proctor, Lester T.; Sebranek, Joshua J.; Pegelow, David F.; Dempsey, Jerome A.

    2010-01-01

    We investigated the role of somatosensory feedback on cardioventilatory responses to rhythmic exercise in five men. In a double-blind, placebo-controlled design, subjects performed the same leg cycling exercise (50/100/150/325 ± 19 W, 3 min each) under placebo conditions (interspinous saline, L3–L4) and with lumbar intrathecal fentanyl impairing central projection of spinal opioid receptor-sensitive muscle afferents. Quadriceps strength was similar before and after fentanyl administration. To evaluate whether a cephalad migration of fentanyl affected cardioventilatory control centers in the brain stem, we compared resting ventilatory responses to hypercapnia (HCVR) and cardioventilatory responses to arm vs. leg cycling exercise after each injection. Similar HCVR and minor effects of fentanyl on cardioventilatory responses to arm exercise excluded direct medullary effects of fentanyl. Central command during leg exercise was estimated via quadriceps electromyogram. No differences between conditions were found in resting heart rate (HR), ventilation [minute ventilation (V̇e)], or mean arterial pressure (MAP). Quadriceps electromyogram, O2 consumption (V̇o2), and plasma lactate were similar in both conditions at the four steady-state workloads. Compared with placebo, a substantial hypoventilation during fentanyl exercise was indicated by the 8–17% reduction in V̇e/CO2 production (V̇co2) secondary to a reduced breathing frequency, leading to average increases of 4–7 Torr in end-tidal Pco2 (P < 0.001) and a reduced hemoglobin saturation (−3 ± 1%; P < 0.05) at the heaviest workload (∼90% maximal V̇o2) with fentanyl. HR was reduced 2–8%, MAP 8–13%, and ratings of perceived exertion by 13% during fentanyl vs. placebo exercise (P < 0.05). These findings demonstrate the essential contribution of muscle afferent feedback to the ventilatory, cardiovascular, and perceptual responses to rhythmic exercise in humans, even in the presence of unaltered contributions from other major inputs to cardioventilatory control. PMID:20634355

  6. The effects of high-fat diet, branched-chain amino acids and exercise on female C57BL/6 mouse Achilles tendon biomechanical properties

    PubMed Central

    Boivin, G. P.; Platt, K. M.; Corbett, J.; Reeves, J.; Hardy, A. L.; Elenes, E. Y.; Charnigo, R. J.; Hunter, S. A.; Pearson, K. J.

    2013-01-01

    Objectives The goals of this study were: 1) to determine if high-fat diet (HFD) feeding in female mice would negatively impact biomechanical and histologic consequences on the Achilles tendon and quadriceps muscle; and 2) to investigate whether exercise and branched-chain amino acid (BCAA) supplementation would affect these parameters or attenuate any negative consequences resulting from HFD consumption. Methods We examined the effects of 16 weeks of 60% HFD feeding, voluntary exercise (free choice wheel running) and BCAA administration in female C57BL/6 mice. The Achilles tendons and quadriceps muscles were removed at the end of the experiment and assessed histologically and biomechanically. Results HFD feeding significantly decreased the Achilles tendon modulus without histological alterations. BCAA administration significantly decreased the stiffness of Achilles tendons in the exercised normal diet mice. Exercise partially ameliorated both the weight gain and glucose levels in the HFD-fed mice, led to a significant decrease in the maximum load of the Achilles tendon, and an increase in the average fibril diameter of the quadriceps femoris muscle. There were significant correlations between body weight and several biomechanical properties, demonstrating the importance of controlling obesity for maintaining healthy tendon properties. Conclusions In summary, this study showed a significant impact of obesity and body weight on tendon biomechanical properties with limited effects of exercise and BCAAs. Cite this article: Bone Joint Res 2013;2:186–92. PMID:24021530

  7. Back Exercises

    PubMed Central

    Livingston, Michael

    1992-01-01

    Thirty patients with low back pain were referred for examination by their doctors after 3 or more weeks of treatment. Whether back exercise instruction had been given, who had given it, what it was, and whether the patients actually followed the instruction was noted. Some type of back exercise had been taught to 22 patients, but only three out of the 30 patients had persisted with all the back exercises taught. The back exercises patients actually do and the role of exercise in low back pain should be evaluated further. PMID:21221344

  8. Heat treatment strengthens human dentin.

    PubMed

    Hayashi, M; Koychev, E V; Okamura, K; Sugeta, A; Hongo, C; Okuyama, K; Ebisu, S

    2008-08-01

    The flexural strength of Type I collagen, the major organic component of human dentin, increases with heat. We hypothesized that human dentin can be strengthened by heating, which may help prevent fracture of non-vital teeth after restoration. Beam-shaped dentin specimens were obtained from the crowns of human third molars. The dentinal tubular orientations were arranged to run parallel or perpendicular to loading surfaces. The flexural and microtensile strengths of dentin in the parallel specimens were 2- to 2.4-fold greater after being heated between 110 degrees C and 140 degrees C for 1 hr. The stress intensity factors at fracture also increased after specimens were heated. The x-ray diffraction analyses suggested that shrinking of the lateral packing of the collagen triple-helices from 14 A to 11 A was the probable cause of the strengthening of heated dentin. We conclude that heat treatment strengthens human dentin. PMID:18650549

  9. Self-regulation strategies may enhance the acute effect of exercise on smoking delay.

    PubMed

    Hatzigeorgiadis, Antonis; Pappa, Vassiliki; Tsiami, Anastasia; Tzatzaki, Theodora; Georgakouli, Kalliopi; Zourbanos, Nikos; Goudas, Marios; Chatzisarantis, Nikos; Theodorakis, Yannis

    2016-06-01

    The present study examined the acute effect of a moderate intensity aerobic exercise session combined with self-regulation on smoking delay in physically inactive smokers. Participants were 11 adults (5 males and 6 females) that completed three experimental conditions: control, exercise, and exercise using self-regulation strategies (SR). Following the experimental treatment smoking for the two exercise conditions delayed significantly more than for the control condition; in addition exercise SR delayed smoking marginally more that the plain exercise condition. Findings supported previous research that acute exercise reduces cravings to smoke, and suggests that the use of self-regulation strategies may strengthen exercise for smoking cessation interventions. PMID:26851493

  10. Lack of Correlation between Dynamic Balance and Hamstring-to-Quadriceps Ratio in Patients with Chronic Anterior Cruciate Ligament Tears

    PubMed Central

    Lee, Jin-Hyuck; Jeong, Hye-Jin; Lee, Seok-Joo

    2015-01-01

    Purpose The purpose of this study was to evaluate the quadriceps and hamstring muscle strength and hamstring-to-quadriceps (HQ) ratio, as well as the relationships of these parameters with dynamic balance, in patients with anterior cruciate ligament (ACL) rupture. Materials and Methods We compared 25 patients diagnosed with chronic unilateral ACL tears and 25 age-matched healthy volunteers. The maximal torque of the quadriceps and hamstring and dynamic balance were measured. Results Although the isokinetic maximal peak torques were about 50% lower in the quadriceps (57%, p<0.001) and hamstring (56%, p=0.001) muscles in the chronic ACL tear group than in the control group, their HQ ratios were similar (56%±17% vs. 58%±6%, p=0.591). HQ ratio was significantly correlated with anterior-posterior stability index (r=-0.511, p=0.021) and overall stability index (r=-0.476, p=0.034) in control group, but these correlations were not observed in chronic ACL tear group. Conclusions Thigh muscle strength was about 50% lower in the chronic ACL tear group than in the control group, but the HQ ratio was similar. The dynamic balance of the knee was not influenced by thigh muscle strength but was influenced by HQ ratio in healthy young individuals. However, HQ ratio was not correlated with dynamic knee balance in chronic ACL tear patients. PMID:26060609

  11. Effect of a Periodized Power Training Program on the Functional Performances and Contractile Properties of the Quadriceps in Sprinters

    ERIC Educational Resources Information Center

    Kamandulis, Sigitas; Skurvydas, Albertas; Brazaitis, Marius; Stanislovaitis, Aleksas; Duchateau, Jacques; Stanislovaitiene, Jurate

    2012-01-01

    Our purpose was to compare the effect of a periodized preparation consisting of power endurance training and high-intensity power training on the contractile properties of the quadriceps muscle and functional performances in well trained male sprinters (n = 7). After 4 weeks of high-intensity power training, 60-m sprint running time improved by an…

  12. Effect of a Periodized Power Training Program on the Functional Performances and Contractile Properties of the Quadriceps in Sprinters

    ERIC Educational Resources Information Center

    Kamandulis, Sigitas; Skurvydas, Albertas; Brazaitis, Marius; Stanislovaitis, Aleksas; Duchateau, Jacques; Stanislovaitiene, Jurate

    2012-01-01

    Our purpose was to compare the effect of a periodized preparation consisting of power endurance training and high-intensity power training on the contractile properties of the quadriceps muscle and functional performances in well trained male sprinters (n = 7). After 4 weeks of high-intensity power training, 60-m sprint running time improved by an

  13. A method of repair for quadriceps tendon or patellar ligament (tendon) ruptures without cast immobilization. Preliminary report.

    PubMed

    Levy, M; Goldstein, J; Rosner, M

    1987-05-01

    The quadriceps tendon and patellar tendon (ligament) were repaired with a Dacron vascular graft used as a tension suture material. In cases of quadriceps tendon ruptures, the Dacron graft is passed transversely through the patellar ligament just below the patella and crossed transversely at the level of the musculotendinous junction with two loops applying tension to the tendon, which brings the tendon ends together by creating a solid structure. In cases of patellar ligament ruptures, the Dacron graft is passed through a hole in the tibia posteriorly to the tibial tuberosity instead of through the patellar ligament below the patella. This technique enables early mobilization on the first day after surgery. The technique was first tested on six dogs with severed quadriceps tendons and patellar ligaments that were repaired with this suture method. All of the animals recovered from surgery and walked and ran normally on the repaired legs within 27 days and with only mild limping after 17 days. The technique was then used on six patients, four with complete quadriceps tendon rupture and two with complete tear (avulsion) of the patellar ligament (tendon). In all of the patients, excellent surgical results were obtained and leg immobilization was virtually eliminated. Physical therapy was prescribed the first day after surgery. The rehabilitation period was significantly reduced. PMID:2952384

  14. Comparison of Lower Body Specific Resistance Training on the Hamstring to Quadriceps Strength Ratios in Men and Women

    ERIC Educational Resources Information Center

    Dorgo, Sandor; Edupuganti, Pradeep; Smith, Darla R.; Ortiz, Melchor

    2012-01-01

    In this study, we compared hamstring (H) and quadriceps (Q) strength changes in men and women, as well as changes in conventional and functional H:Q ratios following an identical 12-week resistance training program. An isokinetic dynamometer was used to assess 14 male and 14 female participants before and after the intervention, and conventional

  15. Comparison of Lower Body Specific Resistance Training on the Hamstring to Quadriceps Strength Ratios in Men and Women

    ERIC Educational Resources Information Center

    Dorgo, Sandor; Edupuganti, Pradeep; Smith, Darla R.; Ortiz, Melchor

    2012-01-01

    In this study, we compared hamstring (H) and quadriceps (Q) strength changes in men and women, as well as changes in conventional and functional H:Q ratios following an identical 12-week resistance training program. An isokinetic dynamometer was used to assess 14 male and 14 female participants before and after the intervention, and conventional…

  16. Clinical outcomes after repair of quadriceps tendon rupture: a systematic review.

    PubMed

    Ciriello, Vincenzo; Gudipati, Suribabu; Tosounidis, Theodoros; Soucacos, P N; Giannoudis, Peter V

    2012-11-01

    The existing evidence regarding the management of quadriceps tendon rupture remains obscure. The aim of the current review is to investigate the characteristics, the different techniques employed and to analyse the clinical outcomes following surgical repair of quadriceps tendon rupture. An Internet based search of the English literature of the last 25 years was carried out. Case reports and non-clinical studies were excluded. The methodological quality of the included studies was assessed using the Coleman Methodology Score. All data regarding mechanism and site of rupture, type of treatment, time elapsed between diagnosis and repair, patients' satisfaction, clinical outcome, return to pre-injury activities, complications and recurrence rates were extracted and analysed. Out of 474 studies identified, 12 met the inclusion criteria. The average of Coleman Methodology Score was 50.46/100. In total 319 patients were analysed with a mean age of 57 years (16-85). The mean time of follow-up was 47.5 months (3 months to 24 years). The most common mechanism of injury was simple fall (61.5%). Spontaneous ruptures were reported in 3.2% of cases. The most common sites of tear were noted between 1cm and 2 cm of the superior pole of the patella and, in the older people, at the osseotendinous junction. The most frequently used repair technique was patella drill holes (50% of patients). Simple sutures were used in mid-substance ruptures. Several reinforcement techniques were employed in case of poor quality or retraction of the torn ends of tendon. The affected limb was immobilised in a cast for a period of 3-10 weeks. Quadriceps muscular atrophy and muscle strength deficit were present in most of the cases. Worst results were noted in delayed repairs. Reported complications included heterotopic ossifications in 6.9% of patients, deep venous thrombosis or pulmonary embolism in 2.5%, superficial infection in 1.2% and deep infection in 1.1%. It appears that the type of surgical repair does not influence the clinical results. The majority of the studies reported good or excellent ROM and return to the pre-injury activities. The overall rate of re-rupture was 2%. PMID:22959496

  17. Prevalence of abnormal patellofemoral congruence in elite American football players and association with quadriceps isokinetic testing.

    PubMed

    Brown, Christopher A; Carragee, Cat; Sox-Harris, Alex; Merchant, Alan C; Mcadams, Timothy R

    2014-02-01

    Abnormal patellofemoral joint alignment has been discussed as a potential risk factor for patellofemoral disorders and can impact the longevity of any elite athlete's career. The prevalence of abnormal patellofemoral congruence in elite American football athletes is similar to the general population and does not have a relationship with quadriceps isokinetic testing. A total of 125 athletes (220 knees) from the 2011 National Football League (NFL) Combine database who had radiographic and isokinetic studies were reviewed. Congruence angles (CA) and lateral patellofemoral angles (LPA) were calculated on a Merchant radiographic view. Isokinetic testing was used to determine quadriceps-to-hamstring strength (Q/H) ratio and side-to-side deficits. The relationships between abnormal CA and LPA with Q/H ratios, side-to-side deficits, and body mass index (BMI) were examined in separate logistic regression models. A Chi-square test was used to examine the association between CA and player position. Of all, 26.8% of the knees (95% CI: 21.1-33.2%) had an abnormal CA. Knees with normal CA (n = 161) did not significantly differ from those with an abnormal CA (n  = 59) in Q/H ratios (mean: 0.699 vs. 0.728, p = 0.19) or side-to-side quadriceps deficits (mean: 4.0 vs. 1.24, p  = 0.45). For each point increase in BMI, the odds ratio (OR) of abnormal congruence increased by 11.4% (p = 0.002). Of all the knees, 4.1% (95% CI: 1.9-7.6%) had an abnormal LPA, and this was not associated with Q/H ratios (p  =  0.13). For each point increase in BMI, the odds of abnormal LPA increased by 16% (p  = 0.036). CA abnormality had much higher odds of having an abnormal LPA (OR: 5.96, p = 0.014). We found that abnormal patellofemoral radiographic alignment in elite American football players is relatively common and there was no association with isokinetic testing. PMID:23925950

  18. Summer Science Can Strengthen Skills.

    ERIC Educational Resources Information Center

    Pugh, Ava F.; Smith, Ruby

    1989-01-01

    Described are 22 activities which can be done by students outside of school. Topics include the seashore, shadows, restaurants, water, amusement parks, factories, museums, camping, weather, animals, photography, plants, food, and exercise. (CW)

  19. Effects of a short proprioceptive neuromuscular facilitation stretching bout on quadriceps neuromuscular function, flexibility, and vertical jump performance.

    PubMed

    Place, Nicolas; Blum, Yannick; Armand, Stéphane; Maffiuletti, Nicola A; Behm, David G

    2013-02-01

    The inclusion of relatively long bouts of stretching (repeated static stretches of ∼30 seconds) in the warm-up is usually associated with a drop in muscle performance. The purpose of this study was to assess the effect of a novel self-administered proprioceptive neuromuscular facilitation (PNF) paradigm with short periods of stretching and contraction on quadriceps neuromuscular function, vertical jump performance, and articular range of motion (ROM). Twelve healthy men (age: 27.7 ± 7.3 years, height: 178.4 ± 10.4 cm, weight: 73.8 ± 16.9 kg) volunteered to participate in a PNF session and a control session separated by 2-7 days. The PNF stretching lasted 2 minutes and consisted of 4 sets of 5-second isometric hamstring contraction immediately followed by 5 seconds of passive static stretch of the quadriceps immediately followed by 5 seconds isometric quadriceps contraction for each leg. For the control session, the participants were asked to walk at a comfortable speed for 2 minutes. Active ROM of knee flexion, vertical jump performance, and quadriceps neuromuscular function were tested before, immediately after, and 15 minutes after the intervention. The PNF stretching procedure did not affect ROM, squat jump, and countermovement jump performances. Accordingly, we did not observe any change in maximal voluntary contraction force, voluntary activation level, M-wave and twitch contractile properties that could be attributed to PNF stretching. The present self-administered PNF stretching of the quadriceps with short (5-second) stretches is not recommended before sports where flexibility is mandatory for performance. PMID:22505131

  20. Strengthening emotion-cognition integration.

    PubMed

    Todd, Rebecca; Thompson, Evan

    2015-01-01

    Pessoa's (2013) integrative model of emotion and cognition can be strengthened in two ways: first, by clarification and refinement of key concepts and terminology, and second by the incorporation of an additional key neural system into the model, the locus coeruleus/norepinephrine system. PMID:26786572

  1. Morel-Lavallee Lesion Initially Diagnosed as Quadriceps Contusion: Ultrasound, MRI, and Importance of Early Intervention

    PubMed Central

    Weiss, Nicholas A.; Johnson, Jeremiah J.; Anderson, Shane B.

    2015-01-01

    Morel-Lavallee lesions (MLL) are rare, closed degloving injuries caused by trauma that delivers a shearing force to the soft tissue most commonly of the hip. If not treated in the acute and subacute setting these lesions are often complicated by re-accumulation of fluid, infection, or chronic pain. We present a unique case of a recurrent, massive medial knee/thigh MLL in which proper treatment was delayed due to initial diagnosis of a quadriceps contusion. We describe the ultrasound and magnetic resonance imaging findings of this patient and based on a review of recent literature propose that the initial management should have included early drainage/debridement, which likely could have prevented recurrence and significantly shortened the clinical course. PMID:25987925

  2. Morel-LAvallee lesion initially diagnosed as quadriceps contusion: ultrasound, MRI, and importance of early intervention.

    PubMed

    Weiss, Nicholas A; Johnson, Jeremiah J; Anderson, Shane B

    2015-05-01

    Morel-Lavallee lesions (MLL) are rare, closed degloving injuries caused by trauma that delivers a shearing force to the soft tissue most commonly of the hip. If not treated in the acute and subacute setting these lesions are often complicated by re-accumulation of fluid, infection, or chronic pain. We present a unique case of a recurrent, massive medial knee/thigh MLL in which proper treatment was delayed due to initial diagnosis of a quadriceps contusion. We describe the ultrasound and magnetic resonance imaging findings of this patient and based on a review of recent literature propose that the initial management should have included early drainage/debridement, which likely could have prevented recurrence and significantly shortened the clinical course. PMID:25987925

  3. Effects of functional electrical stimulation (FES) on evoked muscular output in paraplegic quadriceps muscle.

    PubMed

    Rabischong, E; Ohanna, F

    1992-07-01

    In order to assess the effects of FES on muscle output, chronic electrical stimulation of the quadriceps muscle was applied for half an hour twice a day for 2 months, in 10 thoracic level traumatic paraplegic patients. Results concerning torque (at 6 different muscle lengths) and fatigue were measured using a strain gauge transducer in isometric condition, and compared with the findings in 15 paraplegic patients who had not received electrical stimulation, and with 10 able bodied subjects with normal motor functions. With training, muscle strength was very significantly improved whilst fatigue resistance remained at a low level. The peak torque was not found to be of the same muscle length when comparing paraplegics and control subjects; it seemed to demonstrate that length-tension relationship of the muscular actuator was changing when it was electrically activated. Moreover, the force recorded in paraplegics remained markedly lower than in able bodied people. PMID:1508560

  4. Low frequency fatigue in human quadriceps is fatigue dependent and not task dependent.

    PubMed

    Iguchi, Masaki; Baldwin, Kris; Boeyink, Charles; Engle, Carol; Kehoe, Michael; Ganju, Anish; Messaros, Andrew J; Shields, Richard K

    2008-04-01

    It is well accepted that a low intensity/long duration isometric contraction induces more low frequency fatigue (LFF) compared to a high-intensity/short-duration contraction. However, previous reports examined the intensity/duration of the contraction but did not control the level of fatigue when concluding fatigue is task dependent. The purpose of this study was to determine whether a long duration/low intensity fatiguing contraction would induce greater LFF than a short duration/high-intensity contraction when the quadriceps muscle was fatigued to similar levels. Eighteen healthy male subjects performed quadriceps contractions sustained at 35% and 65% of maximal voluntary contraction (MVC) on separate days, until the tasks induced a similar amount of fatigue (force generating capacity=45% MVC). Double pulse torque to single pulse torque ratio (D/S ratio) was obtained before, immediately and 5min after fatigue along with the electromyographic (EMG) signal from vastus medialis (VM) and rectus femoris (RF). The D/S ratio significantly (p<0.05) increased by 8.7+/-8.5% (mean+/-SD) and 10.2+/-9.2% after 35% and 65% tasks, respectively, and remained elevated 5min into recovery; however, there was no significant difference in ratio between the two sessions immediately or 5min post-fatigue (p>0.05) even though the endurance time for the 35% fatigue task (124+/-39.68s) was significantly longer (p=0.05) than that of the 65% task (63+/-17.73s). EMG amplitude and median power frequency (MPF) analysis also did not reveal any significant differences between these two sessions after fatigue. These findings indicate that LFF fatigue is fatigue dependent as well as task intensity/duration dependent. These findings assist us in understanding task dependency and muscle fatigue. PMID:17157533

  5. Low frequency fatigue in human quadriceps is fatigue dependent and not task dependent

    PubMed Central

    Iguchi, Masaki; Baldwin, Kris; Boeyink, Charles; Engle, Carol; Kehoe, Michael; Ganju, Anish; Messaros, Andrew J; Shields, Richard K.

    2010-01-01

    It is well accepted that a low intensity/long duration isometric contraction induces more low frequency fatigue (LFF) compared to a high-intensity/short-duration contraction. However, previous reports examined the intensity/duration of the contraction but did not control the level of fatigue when concluding fatigue is task dependent. The purpose of this study was to determine whether a long duration/low intensity fatiguing contraction would induce greater LFF than a short duration/high-intensity contraction when the quadriceps muscle was fatigued to similar levels. Eighteen healthy male subjects performed quadriceps contractions sustained at 35% and 65% of maximal voluntary contraction (MVC) on separate days, until the tasks induced a similar amount of fatigue (force generating capacity = 45% MVC). Double pulse torque to single pulse torque ratio (D/S ratio) was obtained before, immediately and 5 min after fatigue along with the electromyographic (EMG) signal from vastus medialis (VM) and rectus femoris (RF). The D/S ratio significantly (p < 0.05) increased by 8.7 ± 8.5% (mean ± SD) and 10.2 ± 9.2% after 35% and 65% tasks, respectively, and remained elevated 5 min into recovery; however, there was no significant difference in ratio between the two sessions immediately or 5 min post-fatigue (p > 0.05) even though the endurance time for the 35% fatigue task (124 ± 39.68 s) was significantly longer (p = 0.05) than that of the 65% task (63 ± 17.73 s). EMG amplitude and median power frequency (MPF) analysis also did not reveal any significant differences between these two sessions after fatigue. These findings indicate that LFF fatigue is fatigue dependent as well as task intensity/duration dependent. These findings assist us in understanding task dependency and muscle fatigue. PMID:17157533

  6. Monogyny and regulation of worker mating in the queenless ant Dinoponera quadriceps

    PubMed

    Monnin; Peeters

    1998-02-01

    The morphologically specialized queen caste has been lost in various ponerine ants, and mated workers ('gamergates') reproduce instead of queens. Unlike previous reports in the literature, we found only one gamergate in each colony of Dinoponera quadriceps. We documented monogyny by dissecting ovaries and spermathecae in 914 workers from 15 colonies, and by observing mating in the laboratory. In colonies without a gamergate, aggressive interactions among some of the unmated nestmates led to the behavioural differentiation of a top-ranking worker ('alpha'), which laid almost all the eggs. Only the alpha went outside the nest at night, and mated if foreign males were present (N=11 tests), thus becoming a gamergate. The alpha was sexually attractive even when her ovaries were not yet active. After intromission, the male remained linked to the alpha while she severed the end of his abdomen. Pieces of the male genitalia remained attached to her genital tract, and she removed them after 30+/-18 min (X+/-sdN=9). We interpret this to be a mating plug, preventing other males from fathering her offspring. None of these newly inseminated gamergates continued to go outside the nest, and, when tested, they never re-mated (N=4). Thus, gamergates of D. quadriceps probably mate only once. In queenless ant species, comparative evidence indicates that worker mating is often regulated in monogynous species, while unrestricted mating of young individuals is typical of polygynous species (oviposition is regulated subsequently). Furthermore, the occurrence of either monogyny or polygyny influences the mating strategies of males, and mating plugs have been reported only in some monogynous species. Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9480697

  7. Interstitial pH, K(+), lactate, and phosphate determined with MSNA during exercise in humans

    NASA Technical Reports Server (NTRS)

    MacLean, D. A.; Imadojemu, V. A.; Sinoway, L. I.

    2000-01-01

    The purpose of the present study was to use the microdialysis technique to simultaneously measure the interstitial concentrations of several putative stimulators of the exercise pressor reflex during 5 min of intermittent static quadriceps exercise in humans (n = 7). Exercise resulted in approximately a threefold (P < 0.05) increase in muscle sympathetic nerve activity (MSNA) and 13 +/- 3 beats/min (P < 0.05) and 20 +/- 2 mmHg (P < 0.05) increases in heart rate and blood pressure, respectively. During recovery, all reflex responses quickly returned to baseline. Interstitial lactate levels were increased (P < 0.05) from rest (1.1 +/- 0.1 mM) to exercise (1. 6 +/- 0.2 mM) and were further increased (P < 0.05) during recovery (2.0 +/- 0.2 mM). Dialysate phosphate concentrations were 0.55 +/- 0. 04, 0.71 +/- 0.05, and 0.48 +/- 0.03 mM during rest, exercise, and recovery, respectively, and were significantly elevated during exercise. At the onset of exercise, dialysate K(+) levels rose rapidly above resting values (4.2 +/- 0.1 meq/l) and continued to increase during the exercise bout. After 5 min of contractions, dialysate K(+) levels had peaked with an increase (P < 0.05) of 0.6 +/- 0.1 meq/l and subsequently decreased during recovery, not being different from rest after 3 min. In contrast, H(+) concentrations rapidly decreased (P < 0.05) from resting levels (69.4 +/- 3.7 nM) during quadriceps exercise and continued to decrease with a mean decline (P < 0.05) of 16.7 +/- 3.8 nM being achieved after 5 min. During recovery, H(+) concentrations rapidly increased and were not significantly different from baseline after 1 min. This study represents the first time that skeletal muscle interstitial pH, K(+), lactate, and phosphate have been measured in conjunction with MSNA, heart rate, and blood pressure during intermittent static quadriceps exercise in humans. These data suggest that interstitial K(+) and phosphate, but not lactate and H(+), may contribute to the stimulation of the exercise pressor reflex.

  8. The role of exercise in the treatment of osteoporosis.

    PubMed

    Sinaki, Mehrsheed; Pfeifer, Michael; Preisinger, Elisabeth; Itoi, Eiji; Rizzoli, René; Boonen, Steven; Geusens, Piet; Minne, Helmut W

    2010-09-01

    The objective of exercise in the treatment of osteoporosis is to improve axial stability through improvement of muscle strength. Therefore, a back extension exercise program specific to one's musculoskeletal competence and pain can be performed in a sitting position and later advanced to the prone position. When fragility is resolved, back extension is performed against resistance applied to the upper back. To decrease pain and immobility in acute vertebral fracture, use of spinal orthoses become inevitable. Therapeutic exercise should address osteoporosis-related deformities of axial posture, which can increase risk of fall and fracture. Strengthening of the major appendicular muscles decreases fragility. The effect of strengthening exercise is augmented by proper intake of cholecalciferol and calcium. Thus, the role of a therapeutic exercise program is to increase muscle strength safely, decrease immobility-related complications, and prevent fall and fracture. As with pharmacotherapy, therapeutic exercises are individualized. PMID:20574788

  9. Segmental stabilization and muscular strengthening in chronic low back pain ‐ a comparative study

    PubMed Central

    França, Fábio Renovato; Burke, Thomaz Nogueira; Hanada, Erica Sato; Marques, Amélia Pasqual

    2010-01-01

    OBJECTIVE: To contrast the efficacy of two exercise programs, segmental stabilization and strengthening of abdominal and trunk muscles, on pain, functional disability, and activation of the transversus abdominis muscle (TrA), in individuals with chronic low back pain. DESIGN: Our sample consisted of 30 individuals, randomly assigned to one of two treatment groups: segmental stabilization, where exercises focused on the TrA and lumbar multifidus muscles, and superficial strengthening, where exercises focused on the rectus abdominis, abdominus obliquus internus, abdominus obliquus externus, and erector spinae. Groups were examined to discovere whether the exercises created contrasts regarding pain (visual analogical scale and McGill pain questionnaire), functional disability (Oswestry disability questionnaire), and TrA muscle activation capacity (Pressure Biofeedback Unit  =  PBU). The program lasted 6 weeks, and 30‐minute sessions occurred twice a week. Analysis of variance was used for inter‐ and intra‐group comparisons. The significance level was established at 5%. RESULTS: As compared to baseline, both treatments were effective in relieving pain and improving disability (p<0.001). Those in the segmental stabilization group had significant gains for all variables when compared to the ST group (p<0.001), including TrA activation, where relative gains were 48.3% and ‐5.1%, respectively. CONCLUSION: Both techniques lessened pain and reduced disability. Segmental stabilization is superior to superficial strengthening for all variables. Superficial strengthening does not improve TrA activation capacity. PMID:21120303

  10. Epidemiological investigation of muscle-strengthening activities and cognitive function among older adults.

    PubMed

    Loprinzi, Paul D

    2016-06-01

    Limited research has examined the association of muscle-strengthening activities and executive cognitive function among older adults, which was this study's purpose. Data from the 1999-2002 NHANES were employed (N = 2157; 60-85 years). Muscle-strengthening activities were assessed via self-report, with cognitive function assessed using the digit symbol substitution test. After adjusting for age, age-squared, gender, race-ethnicity, poverty level, body mass index, C-reactive protein, smoking, comorbid illness and physical activity, muscle-strengthening activities were significantly associated with cognitive function (βadjusted = 3.4; 95% CI: 1.7-5.1; P < 0.001). Compared to those not engaging in aerobic exercise and not meeting muscle-strengthening activity guidelines, those doing 1 (βadjusted = 3.7; 95% CI: 1.9-5.4; P < 0.001) and both (βadjusted = 6.6; 95% CI: 4.8-8.3; P < 0.001) of these behaviors had a significantly higher executive cognitive function score. In conclusion, muscle-strengthening activities are associated with executive cognitive function among older U.S. adults, underscoring the importance of promoting both aerobic exercise and muscle-strengthening activities to older adults. PMID:27048445

  11. Meta-analysis of the effect of strengthening interventions in individuals with cerebral palsy.

    PubMed

    Park, Eun-Young; Kim, Won-Ho

    2014-02-01

    This study aimed to investigate the evidence that strengthening interventions can improve muscle strength and activity in individuals with cerebral palsy. The search focused on studies that employed strength training for children with cerebral palsy for which six electronic databases were used to extract literature published from 2001 to 2012. The key terms used in these searches were combined strength training, strengthening, weight training, weight lifting, resistance, and cerebral palsy. The quality of each study was assessed using the PEDro (Physiotherapy Evidence Database) scale. Thirteen randomized controlled trial studies were selected and divided into categories according to program type, mode, and outcome measures. The overall effect sizes of each study and types of strengthening were large. Strengthening exercise improved muscle strength to a greater degree, when practiced 3 times per week in 40-50 min sessions than in other categories of session length, and greater improvement was observed in younger children than in older. The effect size of the activities and variables related to gait, except for gait endurance, were medium to large. The effect size of individual muscles was large, but the effect sizes for ankle plantar flexor, hip abductor/adductor, and extensor were insignificant. Strengthening interventions are useful for increasing muscle strength in individuals with cerebral palsy, specifically in youth and children, and optimal exercise consisted of 40- to 50-min sessions performed 3 times per week. Although strengthening interventions may improve activities, including gait, more studies that are rigorous are needed to determine the contributions to gross motor function. PMID:24291625

  12. Improved Inflammatory Balance of Human Skeletal Muscle during Exercise after Supplementations of the Ginseng-Based Steroid Rg1

    PubMed Central

    Hou, Chien-Wen; Lee, Shin-Da; Kao, Chung-Lan; Cheng, I-Shiung; Lin, Yu-Nan; Chuang, Sheng-Ju; Chen, Chung-Yu; Ivy, John L.; Huang, Chih-Yang; Kuo, Chia-Hua

    2015-01-01

    The purpose of the study was to determine the effect of ginseng-based steroid Rg1 on TNF-alpha and IL-10 gene expression in human skeletal muscle against exercise challenge, as well as on its ergogenic outcomes. Randomized double-blind placebo-controlled crossover trials were performed, separated by a 4-week washout. Healthy young men were randomized into two groups and received capsule containing either 5 mg of Rg1 or Placebo one night and one hour before exercise. Muscle biopsies were conducted at baseline, immediately and 3 h after a standardized 60-min cycle ergometer exercise. While treatment differences in glycogen depletion rate of biopsied quadriceps muscle during exercise did not reach statistical significance, Rg1 supplementations enhanced post-exercise glycogen replenishment and increased citrate synthase activity in the skeletal muscle 3 h after exercise, concurrent with improved meal tolerance during recovery (P<0.05). Rg1 suppressed the exercise-induced increases in thiobarbituric acids reactive substance (TBARS) and reversed the increased TNF-alpha and decreased IL-10 mRNA of quadriceps muscle against the exercise challenge. PGC-1 alpha and GLUT4 mRNAs of exercised muscle were not affected by Rg1. Maximal aerobic capacity (VO2max) was not changed by Rg1. However, cycling time to exhaustion at 80% VO2max increased significantly by ~20% (P<0.05). Conclusion: Our result suggests that Rg1 is an ergogenic component of ginseng, which can minimize unwanted lipid peroxidation of exercised human skeletal muscle, and attenuate pro-inflammatory shift under exercise challenge. PMID:25617625

  13. The effect of rowing ergometry and resistive exercise on skeletal muscle structure and function during bed rest.

    PubMed

    Krainski, Felix; Hastings, Jeffrey L; Heinicke, Katja; Romain, Nadine; Pacini, Eric L; Snell, Peter G; Wyrick, Phil; Palmer, M Dean; Haller, Ronald G; Levine, Benjamin D

    2014-06-15

    Exposure to microgravity causes functional and structural impairment of skeletal muscle. Current exercise regimens are time-consuming and insufficiently effective; an integrated countermeasure is needed that addresses musculoskeletal along with cardiovascular health. High-intensity, short-duration rowing ergometry and supplemental resistive strength exercise may achieve these goals. Twenty-seven healthy volunteers completed 5 wk of head-down-tilt bed rest (HDBR): 18 were randomized to exercise, 9 remained sedentary. Exercise consisted of rowing ergometry 6 days/wk, including interval training, and supplemental strength training 2 days/wk. Measurements before and after HDBR and following reambulation included assessment of strength, skeletal muscle volume (MRI), and muscle metabolism (magnetic resonance spectroscopy); quadriceps muscle biopsies were obtained to assess muscle fiber types, capillarization, and oxidative capacity. Sedentary bed rest (BR) led to decreased muscle volume (quadriceps: -9 ± 4%, P < 0.001; plantar flexors: -19 ± 6%, P < 0.001). Exercise (ExBR) reduced atrophy in the quadriceps (-5 ± 4%, interaction P = 0.018) and calf muscle, although to a lesser degree (-14 ± 6%, interaction P = 0.076). Knee extensor and plantar flexor strength was impaired by BR (-14 ± 15%, P = 0.014 and -22 ± 7%, P = 0.001) but preserved by ExBR (-4 ± 13%, P = 0.238 and +13 ± 28%, P = 0.011). Metabolic capacity, as assessed by maximal O2 consumption, (31)P-MRS, and oxidative chain enzyme activity, was impaired in BR but stable or improved in ExBR. Reambulation reversed the negative impact of BR. High-intensity, short-duration rowing and supplemental strength training effectively preserved skeletal muscle function and structure while partially preventing atrophy in key antigravity muscles. Due to its integrated cardiovascular benefits, rowing ergometry could be a primary component of exercise prescriptions for astronauts or patients suffering from severe deconditioning. PMID:24790012

  14. Sleep On It: How Snoozing Strengthens Memories

    MedlinePLUS

    ... External link, please review our exit disclaimer . Subscribe Sleep On It How Snoozing Strengthens Memories When you ... the best way to remember it is to sleep on it. That’s because sleeping helps strengthen memories ...

  15. Strengthening Mechanisms in Microtruss Metals

    NASA Astrophysics Data System (ADS)

    Ng, Evelyn K.

    Microtrusses are hybrid materials composed of a three-dimensional array of struts capable of efficiently transmitting an externally applied load. The strut connectivity of microtrusses enables them to behave in a stretch-dominated fashion, allowing higher specific strength and stiffness values to be reached than conventional metal foams. While much attention has been given to the optimization of microtruss architectures, little attention has been given to the strengthening mechanisms inside the materials that make up this architecture. This thesis examines strengthening mechanisms in aluminum alloy and copper alloy microtruss systems with and without a reinforcing structural coating. C11000 microtrusses were stretch-bend fabricated for the first time; varying internal truss angles were selected in order to study the accumulating effects of plastic deformation and it was found that the mechanical performance was significantly enhanced in the presence of work hardening with the peak strength increasing by a factor of three. The C11000 microtrusses could also be significantly reinforced with sleeves of electrodeposited nanocrystalline Ni-53wt%Fe. It was found that the strength increase from work hardening and electrodeposition were additive over the range of structures considered. The AA2024 system allowed the contribution of work hardening, precipitation hardening, and hard anodizing to be considered as interacting strengthening mechanisms. Because of the lower formability of AA2024 compared to C11000, several different perforation geometries in the starting sheet were considered in order to more effectively distribute the plastic strain during stretch-bend fabrication. A T8 condition was selected over a T6 condition because it was shown that the plastic deformation induced during the final step was sufficient to enhance precipitation kinetics allowing higher strengths to be reached, while at the same time eliminating one annealing treatment. When hard anodizing treatments were conducted on O-temper and T8 temper AA2024 truss cores, the strength increase was different for different architectures, but was nearly the same for the two parent material tempers. Finally, the question of how much microtruss strengthening can be obtained for a given amount of parent metal strengthening was addressed by examining the interaction of material and geometric parameters in a model system.

  16. 27 CFR 24.153 - Strengthening bonds.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Strengthening bonds. In any instance where the penal sum of the bond on file becomes insufficient, the principal shall either give a strengthening bond with the same surety to attain a sufficient penal sum or give a new bond covering the entire liability. Strengthening bonds will not be approved where any notation...

  17. 27 CFR 41.122 - Strengthening bond.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2011-04-01 2011-04-01 false Strengthening bond. 41.122... States Deferred Payment of Tax in Puerto Rico on Tobacco Products § 41.122 Strengthening bond. Where the... shall immediately file a strengthening bond in an appropriate amount with the same surety as that on...

  18. 27 CFR 26.69 - Strengthening bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Strengthening bonds. 26.69... Liquors and Articles in Puerto Rico Bonds § 26.69 Strengthening bonds. In all cases where the penal sum of any bond becomes insufficient, the principal shall either give a strengthening bond with the...

  19. 27 CFR 40.135 - Strengthening bond.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Strengthening bond. 40.135... PROCESSED TOBACCO Bonds and Extensions of Coverage of Bonds § 40.135 Strengthening bond. Where the amount of... immediately file a strengthening bond in an appropriate amount with the same surety as that on the...

  20. 27 CFR 44.124 - Strengthening bond.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2011-04-01 2011-04-01 false Strengthening bond. 44.124... Strengthening bond. Where the appropriate TTB officer determines that the amount of the bond, under which an... proprietor to file a strengthening bond in an appropriate amount with the same surety as that on the...

  1. 27 CFR 40.135 - Strengthening bond.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2011-04-01 2011-04-01 false Strengthening bond. 40.135... PROCESSED TOBACCO Bonds and Extensions of Coverage of Bonds § 40.135 Strengthening bond. Where the amount of... immediately file a strengthening bond in an appropriate amount with the same surety as that on the...

  2. 27 CFR 44.245 - Strengthening bond.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Strengthening bond. 44.245....245 Strengthening bond. Where the appropriate TTB officer determines that the amount of the bond... appropriate TTB officer may require the proprietor to file a strengthening bond in an appropriate amount...

  3. 27 CFR 40.405 - Strengthening bond.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2011-04-01 2011-04-01 false Strengthening bond. 40.405... § 40.405 Strengthening bond. Where the appropriate TTB officer determines that the amount of the bond... a strengthening bond in an appropriate amount with the same surety as that on the bond already...

  4. 27 CFR 44.245 - Strengthening bond.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2011-04-01 2011-04-01 false Strengthening bond. 44.245....245 Strengthening bond. Where the appropriate TTB officer determines that the amount of the bond... appropriate TTB officer may require the proprietor to file a strengthening bond in an appropriate amount...

  5. 27 CFR 26.69 - Strengthening bonds.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Strengthening bonds. 26.69... Liquors and Articles in Puerto Rico Bonds § 26.69 Strengthening bonds. In all cases where the penal sum of any bond becomes insufficient, the principal shall either give a strengthening bond with the...

  6. 27 CFR 17.107 - Strengthening bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Strengthening bonds. 17... PRODUCTS Bonds and Consents of Sureties § 17.107 Strengthening bonds. Whenever the amount of a bond on file and in effect becomes insufficient, the principal may give a strengthening bond in a sufficient...

  7. 27 CFR 19.246 - Strengthening bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Strengthening bonds. 19... Strengthening bonds. In all cases when the penal sum of any bond becomes insufficient, the principal shall either give a strengthening bond with the same surety to attain a sufficient penal sum, or give a...

  8. 27 CFR 40.405 - Strengthening bond.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Strengthening bond. 40.405... § 40.405 Strengthening bond. Where the appropriate TTB officer determines that the amount of the bond... a strengthening bond in an appropriate amount with the same surety as that on the bond already...

  9. 27 CFR 17.107 - Strengthening bonds.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Strengthening bonds. 17... PRODUCTS Bonds and Consents of Sureties § 17.107 Strengthening bonds. Whenever the amount of a bond on file and in effect becomes insufficient, the principal may give a strengthening bond in a sufficient...

  10. 27 CFR 28.66 - Strengthening bonds.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Strengthening bonds. 28.66... OF THE TREASURY LIQUORS EXPORTATION OF ALCOHOL Bonds and Consents of Surety § 28.66 Strengthening... give a strengthening bond with the same surety to attain a sufficient penal sum, or give a new bond...

  11. 27 CFR 25.94 - Strengthening bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Strengthening bonds. 25.94... OF THE TREASURY LIQUORS BEER Bonds and Consents of Surety § 25.94 Strengthening bonds. (a... strengthening bond in sufficient penal sum if the surety is the same as on the bond in effect. If the surety...

  12. 27 CFR 41.122 - Strengthening bond.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Strengthening bond. 41.122... States Deferred Payment of Tax in Puerto Rico on Tobacco Products § 41.122 Strengthening bond. Where the... shall immediately file a strengthening bond in an appropriate amount with the same surety as that on...

  13. 27 CFR 28.66 - Strengthening bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Strengthening bonds. 28.66... OF THE TREASURY LIQUORS EXPORTATION OF ALCOHOL Bonds and Consents of Surety § 28.66 Strengthening... give a strengthening bond with the same surety to attain a sufficient penal sum, or give a new bond...

  14. 27 CFR 25.94 - Strengthening bonds.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Strengthening bonds. 25.94... OF THE TREASURY LIQUORS BEER Bonds and Consents of Surety § 25.94 Strengthening bonds. (a... strengthening bond in sufficient penal sum if the surety is the same as on the bond in effect. If the surety...

  15. 27 CFR 44.124 - Strengthening bond.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Strengthening bond. 44.124... Strengthening bond. Where the appropriate TTB officer determines that the amount of the bond, under which an... proprietor to file a strengthening bond in an appropriate amount with the same surety as that on the...

  16. Strengthening Families: Community Strategies That Work

    ERIC Educational Resources Information Center

    Olson, Maril

    2007-01-01

    Supporting and strengthening families has always been part of the early childhood professional's unique role in the community. NAEYC's Supporting Teachers, Strengthening Families initiative (www.naeyc.org/ece/supporting) is a set of activities designed to provide intentional leadership and education in the family-strengthening approach. The…

  17. 27 CFR 26.69 - Strengthening bonds.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Strengthening bonds. 26.69... Liquors and Articles in Puerto Rico Bonds § 26.69 Strengthening bonds. In all cases where the penal sum of any bond becomes insufficient, the principal shall either give a strengthening bond with the...

  18. 27 CFR 40.405 - Strengthening bond.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2014-04-01 2014-04-01 false Strengthening bond. 40.405... § 40.405 Strengthening bond. Where the appropriate TTB officer determines that the amount of the bond... a strengthening bond in an appropriate amount with the same surety as that on the bond already...

  19. 27 CFR 17.107 - Strengthening bonds.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Strengthening bonds. 17... PRODUCTS Bonds and Consents of Sureties § 17.107 Strengthening bonds. Whenever the amount of a bond on file and in effect becomes insufficient, the principal may give a strengthening bond in a sufficient...

  20. 27 CFR 26.69 - Strengthening bonds.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Strengthening bonds. 26.69... Liquors and Articles in Puerto Rico Bonds § 26.69 Strengthening bonds. In all cases where the penal sum of any bond becomes insufficient, the principal shall either give a strengthening bond with the...

  1. 27 CFR 17.107 - Strengthening bonds.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Strengthening bonds. 17... PRODUCTS Bonds and Consents of Sureties § 17.107 Strengthening bonds. Whenever the amount of a bond on file and in effect becomes insufficient, the principal may give a strengthening bond in a sufficient...

  2. 27 CFR 40.405 - Strengthening bond.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2012-04-01 2011-04-01 true Strengthening bond. 40.405... § 40.405 Strengthening bond. Where the appropriate TTB officer determines that the amount of the bond... a strengthening bond in an appropriate amount with the same surety as that on the bond already...

  3. 27 CFR 40.405 - Strengthening bond.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2013-04-01 2013-04-01 false Strengthening bond. 40.405... § 40.405 Strengthening bond. Where the appropriate TTB officer determines that the amount of the bond... a strengthening bond in an appropriate amount with the same surety as that on the bond already...

  4. 27 CFR 17.107 - Strengthening bonds.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Strengthening bonds. 17... PRODUCTS Bonds and Consents of Sureties § 17.107 Strengthening bonds. Whenever the amount of a bond on file and in effect becomes insufficient, the principal may give a strengthening bond in a sufficient...

  5. The effect of fatigue and velocity on the relative timing of hamstring activation in relation to quadriceps.

    PubMed

    Abbaszadeh-Amirdehi, Maryam; Khademi-Kalantari, Khosro; Talebian, Saeed; Rezasoltani, Asghar; Hadian, Mohammad Reza

    2012-10-01

    Inter-muscular coordination has an important role in proper function and prevention of injuries in the knee joint. The purpose of this study was to characterize the effect of velocity and fatigue on the relative activation onset of hamstring to quadriceps muscles during knee extension. Thirty one healthy and non-athletic volunteers (24 women, 7 men) were recruited for the study. The onset time of vastus medialis, vastus lateralis, rectus femoris, medial and lateral hamstring were measured during maximum voluntary extension of the knee joint at velocities of 45° /s, 150° /s & 300° /s before and after fatigue and the mean delay onset of all pairs of H-Q were measured. A two-way repeated measures ANOVA test was used to compare across the mean delayed onset of hamstring related to quadriceps muscles at various velocities. Hamstring muscle showed a delayed activation related to quadriceps and increasing the velocity of shortening has a prominent effect on the inter-muscular coordination with early activation of hamstring related to quadriceps muscles (F = 6.7, p < 0.002 for Biceps-rectus femoris, F = 6.31, p < 0.003 for semitendinosus-rectus femoris, F = 6.26, p < 0.003 for biceps-vastus lateralis, F = 5.98, p < 0.004 for semitendinosus-vastus lateralis, F = 3.19, p < 0.04 for biceps-vastus medialis and F = 3.2, p < 0.04 for semitendinosus-vastus medialis). This could predispose these muscles to over strain and possible injuries. The main effect of fatigue condition and its interaction with velocity however, showed statistically nonsignificant result. PMID:23036879

  6. Adverse effect of femoral nerve blockade on quadriceps strength and function after ACL reconstruction.

    PubMed

    Krych, Aaron; Arutyunyan, Grigoriy; Kuzma, Scott; Levy, Bruce; Dahm, Diane; Stuart, Michael

    2015-02-01

    The purpose of this study was to determine if quadriceps strength and functional outcomes were similar at 6 months following anterior cruciate ligament [ACL] reconstruction in patients receiving a continuous 48-hour femoral nerve blockade for postoperative analgesia (FNB group) versus patients with no FNB (control group). A retrospective cohort was designed including athletes who underwent primary ACL reconstruction with patellar tendon autograft between 2005 and 2010 at our institution with identical rehabilitation protocols. The FNB group included 96 patients with an average age of 21 years and the control group included 100 patients with an average age of 20 years. At 6 months following ACL reconstruction, isokinetic strength (slow and fast activation) and functional tests including vertical jump, single hop, triple hop, and return to sport were analyzed with an α value < 0.05 as significant. Multivariate regression models were used to compare these outcomes between the FNB and control groups after adjusting for gender and competitive athlete status. At 6 months, fast extension isokinetic strength was inferior in the FNB group (78 vs. 85%; p < 0.01). After adjusting for gender and competitive athlete status, fast (p = 0.002) and slow extension strength (p = 0.01), vertical jump (p = 0.03) and single jump (p = 0.02) were also inferior in the FNB group. There were no significant differences in full return to sport between the two groups (86% at 7.5 months in the FNB group vs. 93% at 7.3 months in the control group). In this retrospective comparative study, the hypothesis that patients treated with continuous FNB for postoperative analgesia following ACL reconstruction with patellar tendon autograft will have inferior knee extension (quadriceps) strength and function at 6 months follow-up was affirmed. However, no differences were observed in return to sport, bringing into question whether these statistical differences translate into meaningful clinical consequences after ACL reconstruction. The level of evidence was level III, retrospective case-control series. PMID:24622910

  7. Kinesio Taping Does Not Alter Quadriceps Isokinetic Strength and Power in Healthy Nonathletic Men: A Prospective Crossover Study

    PubMed Central

    Korman, Paweł; Straburzyńska-Lupa, Anna; Rutkowski, Radosław; Gruszczyński, Jakub; Lewandowski, Jacek; Straburzyński-Lupa, Marcin; Łochyński, Dawid

    2015-01-01

    Objectives. The effects of Kinesio Taping (KT) on muscular performance remain largely unclear. This study aimed to investigate the acute effects of KT on the maximum concentric and eccentric quadriceps isokinetic strength. Study Design. This is a single-blinded, placebo crossover, repeated measures study. Methods. Maximum isokinetic concentric/eccentric extension torque, work, and power were assessed by an isokinetic dynamometer without taping (NT) and with KT or placebo taping (PT) in 17 healthy young men. Repeated measures one-way analysis of variance (ANOVA) was used for statistical analyses. Results. Testing concentric contractions at 60°/s or 180°/s isokinetic speed, no significant differences in peak torque (Nm), total work (J), or mean power (W) were noted among the application modes under different conditions. Testing eccentric contractions at 30°/s or 60°/s isokinetic speed, no significant differences in mentioned parameters were noted, respectively. KT on the quadriceps neither decreased nor increased muscle strength in the participants. Conclusion. KT application onto the skin overlying the quadriceps muscle does not enhance the strength or power of knee extensors in healthy men. PMID:26819953

  8. Effect of a high intensity quadriceps fatigue protocol on knee joint mechanics and muscle activation during gait in young adults.

    PubMed

    Murdock, Gillian Hatfield; Hubley-Kozey, Cheryl L

    2012-02-01

    The purpose of this study was to determine the effect of impaired quadriceps function on knee joint biomechanics and neuromuscular function during gait. Surface electromyograms, three-dimensional motion and ground reaction forces were collected during gait before and after 20 healthy adults completed a high intensity quadriceps fatigue protocol. Pattern recognition techniques were utilized to examine changes in amplitude and temporal characteristics of all gait variables. The fatigue protocol resulted in decreased knee extensor torque generation and quadriceps median power frequencies for 18 of 20 participants (p < 0.05). The gait data from these 18 participants was analyzed. The knee external rotation angle increased (p < 0.05), the net external flexion and external rotation moments decreased (p < 0.05), and the net external adduction moment increased (p < 0.05). Post-fatigue changes in periarticular muscle activation patterns were consistent with the biomechanical changes, but were not significantly altered. Even for this low demand task of walking the knee motion and loading characteristics were altered following a high intensity fatigue protocol in a manner that may place the knee joint at greater risk for joint pathology and injury. PMID:21573776

  9. Kinesio Taping Does Not Alter Quadriceps Isokinetic Strength and Power in Healthy Nonathletic Men: A Prospective Crossover Study.

    PubMed

    Korman, Paweł; Straburzyńska-Lupa, Anna; Rutkowski, Radosław; Gruszczyński, Jakub; Lewandowski, Jacek; Straburzyński-Lupa, Marcin; Łochyński, Dawid

    2015-01-01

    Objectives. The effects of Kinesio Taping (KT) on muscular performance remain largely unclear. This study aimed to investigate the acute effects of KT on the maximum concentric and eccentric quadriceps isokinetic strength. Study Design. This is a single-blinded, placebo crossover, repeated measures study. Methods. Maximum isokinetic concentric/eccentric extension torque, work, and power were assessed by an isokinetic dynamometer without taping (NT) and with KT or placebo taping (PT) in 17 healthy young men. Repeated measures one-way analysis of variance (ANOVA) was used for statistical analyses. Results. Testing concentric contractions at 60°/s or 180°/s isokinetic speed, no significant differences in peak torque (Nm), total work (J), or mean power (W) were noted among the application modes under different conditions. Testing eccentric contractions at 30°/s or 60°/s isokinetic speed, no significant differences in mentioned parameters were noted, respectively. KT on the quadriceps neither decreased nor increased muscle strength in the participants. Conclusion. KT application onto the skin overlying the quadriceps muscle does not enhance the strength or power of knee extensors in healthy men. PMID:26819953

  10. The influence of velocity-specific resistance training on the in vivo torque-velocity relationship and the cross-sectional area of quadriceps femoris.

    PubMed

    Petersen, S R; Bagnall, K M; Wenger, H A; Reid, D C; Castor, W R; Quinney, H A

    1989-01-01

    This work was supported by Sport Canada end Hydra-Fitness Industries. In order to investigate the effects of velocity-specific resistance training, 30 healthy, male varsity athletes were assigned to either high (HVR) or low (LVR) velocity training or control (CG) groups. Subjects completed two 20-sec sets of maximal exercise at each of six hydraulic resistance stations for the lower limb. Resistances were adjusted as necessary to maintain consistent average angular velocities of approximately 1.05 and 3.14 rad/sec for the LVR and HVR groups, respectively. Subjects trained on alternate days for 6 weeks, completing either two (weeks 1 and 2) or three (weeks 3-6) circuits of the six stations each session. Peak knee extension torques were improved (p < 0.05) for the LVR group at all of seven angular velocities tested between 1.05 and 4.19 rad/sec. Improvements (p < 0.05) were also observed for the HVR group, but only at angular velocities of 2.62, 3.14, 3.66, and 4.19 rad/sec. Cross-sectional area of the quadriceps femoris muscle group obtained from serial computer tomography (CT) scans was increased (p < 0.05) for both training groups. No significant changes in either strength or cross-sectional area were observed for control subjects. These results indicate that while both of the training programs resulted in increased cross-sectional area of the knee extensors, the observed changes in strength performance are likely due to other factors which may be mediated by the different training velocities. J Orthop Sports Phys Ther 1989;10(11):456-462. PMID:18796947

  11. Burnishing Techniques Strengthen Hip Implants

    NASA Technical Reports Server (NTRS)

    2010-01-01

    In the late 1990s, Lambda Research Inc., of Cincinnati, Ohio, received Small Business Innovation Research (SBIR) awards from Glenn Research Center to demonstrate low plasticity burnishing (LPB) on metal engine components. By producing a thermally stable deep layer of compressive residual stress, LPB significantly strengthened turbine alloys. After Lambda patented the process, the Federal Aviation Administration accepted LPB for repair and alteration of commercial aircraft components, the U.S. Department of Energy found LPB suitable for treating nuclear waste containers at Yucca Mountain. Data from the U.S. Food and Drug Administration confirmed LPB to completely eliminate the occurrence of fretting fatigue failures in modular hip implants.

  12. Glass strengthening and patterning methods

    DOEpatents

    Harper, David C; Wereszczak, Andrew A; Duty, Chad E

    2015-01-27

    High intensity plasma-arc heat sources, such as a plasma-arc lamp, are used to irradiate glass, glass ceramics and/or ceramic materials to strengthen the glass. The same high intensity plasma-arc heat source may also be used to form a permanent pattern on the glass surface--the pattern being raised above the glass surface and integral with the glass (formed of the same material) by use of, for example, a screen-printed ink composition having been irradiated by the heat source.

  13. Exercise Physiologists

    MedlinePLUS

    ... kinesiology, and nutrition, as well as clinical work. Education Exercise physiologists typically need at least a bachelor’s ... the skills needed in this occupation. Entry-level Education Typical level of education that most workers need ...

  14. Healthy Exercise

    PubMed Central

    Oberman, Albert

    1984-01-01

    Persons at any age can substantially improve their fitness for work and play through appropriate exercise training. Considerable evidence indicates that physical activity is valuable for weight control, modifying lipids and improving carbohydrate tolerance. Less rigorous scientific data are available for associated long-term blood pressure and psychological changes with habitual exercise. Strenuous physical activity most likely reduces the incidence of coronary heart disease and the detrimental impact of certain chronic diseases on health. Adverse effects may result from a training program, but the major concern is the susceptibility to cardiovascular events during and immediately after exertion. To achieve optimal benefits with minimal risk, exercise must be carefully prescribed within the context of overall health and training objectives. Taken altogether, a distinct rationale exists for regular vigorous exercise as an integral part of a personal health maintenance program. PMID:6395501

  15. Exercise response

    NASA Technical Reports Server (NTRS)

    Rummel, J. A.; Sawin, C. F.; Michel, E. L.

    1975-01-01

    The bicycle ergometer and a graded stress protocol were used to conduct exercise stress tests for the Apollo project. The graded exercise tests permitted a progressive evaluation of physiological control system response and provided a better understanding of safe stress limits; heart rate was used for determining stress levels. During each test, workload, heart rate, blood pressure, and respiratory gas exchange (oxygen consumption, carbon dioxide production, and minute volume) measurements were made. The results are presented and discussed.

  16. Modulation of non-monosynaptic excitation from ankle dorsiflexor afferents to quadriceps motoneurones during human walking

    PubMed Central

    Marchand-Pauvert, V; Nielsen, J B

    2002-01-01

    Modulation of non-monosynaptic excitation from ankle dorsiflexors to quadriceps (Q) motoneurones during human treadmill walking was investigated in 25 healthy human subjects. Stimulation of the common peroneal nerve (CPN) evoked a biphasic facilitation in the rectified and averaged (n = 50) Q electromyographic (EMG) activity between 0 and 100 ms after heel strike. Prior to heel strike, the stimulation had no effect on the Q EMG. The latency of both peaks in the response was too long to be explained by a monosynaptic pathway to Q motoneurones. During voluntary tonic co-contraction of Q and tibialis anterior (TA) while standing, only the first of the two peaks was evoked by the CPN stimulation despite a background EMG activity level in the Q and TA muscles corresponding to that observed 30–60 ms after heel strike during walking. Stimulation of cutaneous nerves did not evoke a similar biphasic facilitation in the Q motoneurones, which suggests that muscular afferents mediate the response. The second peak had a higher threshold than the earlier peak. During cooling of the CPN, the latency of the second peak was more prolonged than the latency of the earlier peak. This suggests that afferents of different diameters contributed to the two peaks. It is proposed that afferents from TA assist the contraction of Q during walking via spinal interneurones to stabilize the knee joint and maintain upright posture during walking. PMID:11790826

  17. Hamstrings-to-quadriceps strength and size ratios of male professional soccer players with muscle imbalance.

    PubMed

    Denadai, Benedito Sérgio; de Oliveira, Felipe Bruno Dias; Camarda, Sérgio Ricardo de Abreu; Ribeiro, Leandro; Greco, Camila Coelho

    2016-03-01

    The aim of this study was to determine the correlation between the concentric hamstrings/quadriceps muscle strength (Hcon :Qcon ) and cross-sectional area ratios (Hcsa :Qcsa ) in professional soccer players with Hcon :Qcon imbalance. Nine male professional soccer players (25·3 ± 4·1 years) performed five maximal concentric contractions of the knee extensors (KE) and flexors (KF) at 60 s(-1) to assess Hcon :Qcon . The test was performed using the dominant (preferred kicking), and non-dominant limb with a 5-min recovery period was allowed between them. Only players with Hcon :Qcon  < 0·60 (range: 0·45-0·59) in both limbs were included in this study. The muscle cross-sectional area (CSA) of KE and KF was determined by magnetic resonance imaging. The correlations between Hcon :Qcon and Hcsa :Qcsa in the dominant leg (r = -0·33), non-dominant leg (r = 0·19) and in the both legs combined (r = 0·28) were not statistically significant (P>0·05). Thus, the Hcon :Qcon seems not to be determined by Hcsa :Qcsa in professional soccer players with Hcon :Qcon imbalance. PMID:25348722

  18. Regression-based indices of fatigue in paraplegics' electrically stimulated quadriceps.

    PubMed

    Rabischong, E; Chavet, P

    1997-12-01

    We studied muscle fatigue in 19 paraplegic patients during an isometric sustained contraction. Both quadriceps (n = 38) were maximally stimulated for 126 s. We defined a nonlinear equation with four coefficients to fit the data and extract fatigue indices carrying information on the amount (asymptotic values, torque coordinate at the inflection point, total decrement from initial value) and the rate of torque decrease (maximum slope, time constant, time coordinate at the inflection point, time at which the torque reached 50% of initial value). Most of the indices reported in the literature provide information limited to the amount of torque decrease. Three of the coefficients we defined could be graphically estimated. The goodness of fit was very high (r2 = 0.993 +/- 0.001) but none of the indices provided information on both the amount and the rate of decrease. Major differences were encountered among the patients. Therefore, some of the computed indices varied to a great extent. We studied the curves exhibiting the same fatigue indices and defined a simple general fatigue index able to distinguish from muscles having different resistance to fatigue (asymptotic value x the time constant). This index is carrying both types of information and is expressed in relative torque x second (range from 1.81 to 22.82). PMID:9450260

  19. Surface action potentials related to torque output in paraplegics' electrically stimulated quadriceps muscle.

    PubMed

    Rabischong, E

    1996-10-01

    We recorded in 15 complete paraplegic patients the torque output and the surface action potentials (SAP) produced by the electrically stimulated quadriceps muscle during an isometric contraction lasting 126 s. We studied the evolution during the test of the peak to peak amplitude, the latency from the onset of stimulation, the rising time to peak, the peak to peak duration, the area of the recorded SAPs and we tried to relate those data to the torque production. Results were extremely different among patients but the general behaviour facing this test was comparable. After a short increase the mechanical output decreased and reached a plateau (range from 7.13 to 53.5% of initial value). The peak to peak amplitude first increased and then decreased, and was not related to the torque production. The latency, the rising time to peak and the peak to peak duration continuously increased to a maximum and then plateaued or slightly decreased after different courses of time. The latency from the onset of stimulation was less affected by the test than the rising time to peak and the peak to peak duration. Therefore, the nerve conduction velocity and the neuromuscular junction transmission did not vary to a great extent compared to the muscle fibre conduction velocity. The area of the rectified SAPs first increased and then decreased and was not related to the torque decrease. PMID:8892238

  20. Effects of quadriceps fatigue on the biomechanics of gait and slip propensity

    PubMed Central

    Parijat, Prakriti; Lockhart, Thurmon E

    2008-01-01

    This study examines how lower extremity fatigue of the quadriceps alters gait variables related to slip propensity. Sixteen healthy young adults were recruited to walk across vinyl floor surfaces in states of fatigue and no fatigue. Kinematic and kinetic data were collected using a three-dimensional motion analysis system and force plates. The results indicated a significant increase in both the heel contact velocity and required coefficient of friction and a decrease in the transitional acceleration of the whole body center of mass and peak knee joint moment in the fatigue trials. Thus, suggesting that slip propensity could increase with fatigue. Additionally, there was increased knee flexion and reduced ankle dorsiflexion at the heel contact phase of the gait cycle during fatigue trials. These findings provide new insights into the biomechanical relationship between localized muscle fatigue and gait parameters associated with slip propensity. The present study concluded that localized muscle fatigue affects gait parameters and hence can be considered as a potential risk factor for slip-induced falls. PMID:18514522

  1. Impact of Pain Reported During Isometric Quadriceps Muscle Strength Testing in People With Knee Pain: Data From the Osteoarthritis Initiative

    PubMed Central

    Stratford, Paul W.

    2011-01-01

    Background Muscle force testing is one of the more common categories of diagnostic tests used in clinical practice. Clinicians have little evidence to guide interpretations of muscle force tests when pain is elicited during testing. Objective The purpose of this study was to examine the construct validity of isometric quadriceps muscle strength tests by determining whether the relationship between maximal isometric quadriceps muscle strength and functional status was influenced by pain during isometric testing. Design A cross-sectional design was used. Methods Data from the Osteoarthritis Initiative were used to identify 1,344 people with unilateral knee pain and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale scores of 1 or higher on the involved side. Measurements of maximal isometric quadriceps strength and ratings of pain during isometric testing were collected. Outcome variables were WOMAC physical function subscale, 20-m walk test, 400-m walk test, and a repeated chair stand test. Multiple regression models were used to determine whether pain during testing modified or confounded the relationship between strength and functional status. Results Pearson r correlations among the isometric quadriceps strength measures and the 4 outcome measures ranged from −.36 (95% confidence interval=−.41, −.31) for repeated chair stands to .36 (95% confidence interval=.31, .41) for the 20-m walk test. In the final analyses, neither effect modification nor confounding was found for the repeated chair stand test, the 20-m walk test, the 400-m walk test, or the WOMAC physical function subscale. Moderate or severe pain during testing was weakly associated with reduced strength, but mild pain was not. Limitations The disease spectrum was skewed toward mild or moderate symptoms, and the pain measurement scale used during muscle force testing was not ideal. Conclusions Given that the spectrum of the sample was skewed toward mild or moderate symptoms and disease, the data suggest that isometric quadriceps muscle strength tests maintain their relationship with self-report or performance-based disability measures even when pain is elicited during testing. PMID:21835892

  2. An age-related shift in the force-frequency relationship affects quadriceps fatigability in old adults.

    PubMed

    Allman, Brian L; Rice, Charles L

    2004-03-01

    We examined the effect of an age-related leftward shift in the force-frequency relationship on the comparative quadriceps fatigability of nine young (27 +/- 1 yr old) and nine old men (78 +/- 1 yr old) during low-frequency electrical stimulation. Two different protocols of intermittent trains (6 pulses on, 650 ms off) of electrical stimulation at 25% maximum voluntary contraction were performed by both groups: 1) 180 trains at 14.3 Hz [constant frequency (CF) protocol], and 2) 180 trains at the frequency corresponding to 60% of each subject's force-frequency curve [normalized frequency (NF) protocol; young 14.9 +/- 0.4 vs. old 12.7 +/- 0.5 Hz; P < 0.05]. The quadriceps of the old men were weaker (approximately 31%) and relaxation was slower compared with the young men, as assessed by the maximal relaxation rate constant of the 50-Hz tetanus (young 12.1 +/- 0.2 vs. old 9.2 +/- 0.5 s(-1); P < 0.05) and a leftward shift in the force-frequency relationship. The NF protocol revealed a decreased fatigability in the quadriceps with old age (percentage of 1st contraction force remaining at 180th: old 63.4 +/- 1.5 vs. young 58.2 +/- 1.7%; P < 0.05) that was masked during the CF protocol (old 60.7 +/- 1.6 vs. young 58.6 +/- 2.3%; P > 0.05). Irrespective of the protocol, the maximal relaxation rate was reduced to approximately 73 and approximately 57% of the prefatigue value in the young and old men, respectively. The age-related leftward shift in the force-frequency relationship of the quadriceps contributed to an underestimation of the fatigue resistance with old age during the CF protocol. However, when the stimulation frequency used in the NF protocol was adjusted to account for the age-related shift in the force-frequency relationship, the quadriceps muscles of the old men were less fatigable than those of the young men. Thus we suggest that whole muscle fatigability is better examined by electrical stimulation protocols that are adjusted for inter- and intragroup differences in the force-frequency relationship. PMID:14594856

  3. Rethinking health research capacity strengthening

    PubMed Central

    Vasquez, Emily; Hirsch, Jennifer S.; Giang, Le Minh; Parker, Richard G.

    2013-01-01

    Health research capacity strengthening (HRCS) is a strategy implemented worldwide to improve the ability of developing countries to tackle the persistent and disproportionate burdens of disease they face. Drawing on a review of existing HRCS literature and our experiences over the course of an NIH-funded HRCS project in Vietnam, we summarise major challenges to the HRCS enterprise at the interpersonal, institutional and macro levels. While over the course of several decades of HRCS initiatives many of these challenges have been well documented, we highlight several considerations that remain under-articulated. We advance critical considerations of the HRCS enterprise by discussing 1) how the organisation of US public health funding shapes the ecology of knowledge production in low- and middle-income country contexts, 2) the barriers US researchers face to effectively collaborating in capacity strengthening for research-to-policy translation, and 3) the potential for unintentional negative consequences if HRCS efforts are not sufficiently reflexive about the limitations of dominant paradigms in public health research and intervention. PMID:23651463

  4. Effect of shoulder girdle strengthening on trunk alignment in patients with stroke

    PubMed Central

    Awad, Amina; Shaker, Hussien; Shendy, Wael; Fahmy, Manal

    2015-01-01

    [Purpose] This study investigated the effect of shoulder girdle strengthening, particularly the scapular muscles, on poststroke trunk alignment. [Subjects and Methods] The study involved 30 patients with residual hemiparesis following cerebrovascular stroke. Patient assessment included measuring shoulder muscle peak torque, scapular muscles peak force, spinal lateral deviation angle, and motor functional performance. Patients were randomly allocated either to the control group or the study group and received an 18-session strengthening program including active resisted exercises for shoulder abductors and external rotators in addition to trunk control exercises. The study group received additional strengthening exercises for the scapular muscles. [Results] The two groups showed significant improvement in strength of all shoulder and scapular muscles, with higher improvement in the study group. Similarly, the lateral spinal deviation angles significantly improved in both groups, with significantly higher improvement in the study group. Transfer activity, sitting balance, upper limb functions, and hand movements significantly improved in the two groups, with higher improvement in the latter two functions in the study group. [Conclusion] Strengthening of shoulder girdle muscles, particularly scapular muscles, can significantly contribute to improving the postural alignment of the trunk in patients with poststroke hemiparesis. PMID:26311953

  5. Effect of shoulder girdle strengthening on trunk alignment in patients with stroke.

    PubMed

    Awad, Amina; Shaker, Hussien; Shendy, Wael; Fahmy, Manal

    2015-07-01

    [Purpose] This study investigated the effect of shoulder girdle strengthening, particularly the scapular muscles, on poststroke trunk alignment. [Subjects and Methods] The study involved 30 patients with residual hemiparesis following cerebrovascular stroke. Patient assessment included measuring shoulder muscle peak torque, scapular muscles peak force, spinal lateral deviation angle, and motor functional performance. Patients were randomly allocated either to the control group or the study group and received an 18-session strengthening program including active resisted exercises for shoulder abductors and external rotators in addition to trunk control exercises. The study group received additional strengthening exercises for the scapular muscles. [Results] The two groups showed significant improvement in strength of all shoulder and scapular muscles, with higher improvement in the study group. Similarly, the lateral spinal deviation angles significantly improved in both groups, with significantly higher improvement in the study group. Transfer activity, sitting balance, upper limb functions, and hand movements significantly improved in the two groups, with higher improvement in the latter two functions in the study group. [Conclusion] Strengthening of shoulder girdle muscles, particularly scapular muscles, can significantly contribute to improving the postural alignment of the trunk in patients with poststroke hemiparesis. PMID:26311953

  6. The effects of hip external rotator exercises and toe-spread exercises on lower extremity muscle activities during stair-walking in subjects with pronated foot

    PubMed Central

    Goo, Young-Mi; Kim, Da-Yeon; Kim, Tae-Ho

    2016-01-01

    [Purpose] The purpose of the present study was to examine the effects of toe-spread (TS) exercises and hip external rotator strengthening exercises for pronated feet on lower extremity muscle activities during stair-walking. [Subjects and Methods] The participants were 20 healthy adults with no present or previous pain, no past history of surgery on the foot or the ankle, and no foot deformities. Ten subjects performed hip external rotator strengthening exercises and TS exercises and the remaining ten subjects performed only TS exercises five times per week for four weeks. [Results] Less change in navicular drop height occurred in the group that performed hip external rotator exercises than in the group that performed only TS exercises. The group that performed only TS exercises showed increased abductor hallucis muscle activity during both stair-climbing and -descending, and the group that performed hip external rotator exercises showed increased muscle activities of the vastus medialis and abductor hallucis during stair-climbing and increased muscle activity of only the abductor hallucis during stair-descending after exercise. [Conclusion] Stair-walking can be more effectively performed if the hip external rotator muscle is strengthened when TS exercises are performed for the pronated foot. PMID:27134364

  7. The effects of hip external rotator exercises and toe-spread exercises on lower extremity muscle activities during stair-walking in subjects with pronated foot.

    PubMed

    Goo, Young-Mi; Kim, Da-Yeon; Kim, Tae-Ho

    2016-03-01

    [Purpose] The purpose of the present study was to examine the effects of toe-spread (TS) exercises and hip external rotator strengthening exercises for pronated feet on lower extremity muscle activities during stair-walking. [Subjects and Methods] The participants were 20 healthy adults with no present or previous pain, no past history of surgery on the foot or the ankle, and no foot deformities. Ten subjects performed hip external rotator strengthening exercises and TS exercises and the remaining ten subjects performed only TS exercises five times per week for four weeks. [Results] Less change in navicular drop height occurred in the group that performed hip external rotator exercises than in the group that performed only TS exercises. The group that performed only TS exercises showed increased abductor hallucis muscle activity during both stair-climbing and -descending, and the group that performed hip external rotator exercises showed increased muscle activities of the vastus medialis and abductor hallucis during stair-climbing and increased muscle activity of only the abductor hallucis during stair-descending after exercise. [Conclusion] Stair-walking can be more effectively performed if the hip external rotator muscle is strengthened when TS exercises are performed for the pronated foot. PMID:27134364

  8. Adaptive Force Regulation of Muscle Strengthening Rehabilitation Device With Magnetorheological Fluids

    PubMed Central

    Dong, Shufang; Lu, Ke-Qian; Sun, Jian Qiao; Rudolph, Katherine

    2008-01-01

    In rehabilitation from neuromuscular trauma or injury, strengthening exercises are often prescribed by physical therapists to recover as much function as possible. Strengthening equipment used in clinical settings range from low-cost devices, such as sandbag weights or elastic bands to large and expensive isotonic and isokinetic devices. The low-cost devices are incapable of measuring strength gains and apply resistance based on the lowest level of torque that is produced by a muscle group. Resistance that varies with joint angle can be achieved with isokinetic devices in which angular velocity is held constant and variable torque is generated when the patient attempts to move faster than the device but are ineffective if a patient cannot generate torque rapidly. In this paper, we report the development of a versatile rehabilitation device that can be used to strengthen different muscle groups based on the torque generating capability of the muscle that changes with joint angle. The device is low cost, is smaller than other commercially available machines, and can be programmed to apply resistance that is unique to a particular patient and that will optimize strengthening. The core of the device, a damper with smart magnetorheological fluids, provides passive exercise force. A digital adaptive control is capable of regulating exercise force precisely following the muscle strengthening profile prescribed by a physical therapist. The device could be programmed with artificial intelligence to dynamically adjust the target force profile to optimize rehabilitation effects. The device provides both isometric and isokinetic strength training and can be developed into a small, low-cost device that may be capable of providing optimal strengthening in the home. PMID:16562632

  9. Effect of regular exercise on health and disease.

    PubMed

    Karacabey, Kursat

    2005-10-01

    It is known for a long time that exercise increases physical adequacy, has beneficial effects on the general health condition as well as a playing preventing role against various disease states. To decrease the risk of disease and maintain good health, the natural defense system of the organism needs to be strengthened. It is thought that in addition to increasing the body's resistance to disease through the strengthening of the immune system, decreases the convalescence time, increases work efficiency and improves the sportive performance of the individual all which would contribute positively to the national economy. The positive effects of regular exercising of aerobic nature such as strengthening of the immune system, protection against diseases as well as its positive effects on quality of life will help to emphasize the importance of physical exercise and improve the general view of sports by society. PMID:16264392

  10. Comparing EMG amplitude patterns of responses during dynamic exercise: polynomial vs log-transformed regression.

    PubMed

    Blaesser, R J; Couls, L M; Lee, C F; Zuniga, J M; Malek, M H

    2015-04-01

    The purposes of this study were to determine if (a) the log-transformed model can be applied to dynamic exercise and (b) the slope and y-intercept terms can provide additional information above and beyond the polynomial regression analyses. Eleven physically active individuals performed incremental cycle ergometry on a single occasion. Electromyographic electrodes were placed on the three superficial quadriceps muscles to record muscle activation during the exercise test. The patterns of responses for electromyographic amplitude vs power output were analyzed with polynomial and log-transformed regression models. The results of the polynomial regression for the composite data indicated that the best-fit model for the vastus lateralis muscle was linear (R(2) = 0.648, P < 0.0001), whereas the best-fit model for the rectus femoris (R(2) = 0.346, P = 0.013) and vastus medialis (R(2) = 0.764,P = 0.020) muscles was quadratic. One-way repeated measures analyses indicated no significant differences(P > 0.05) across the three superficial quadriceps muscles for the slope and y-intercept terms. These findings suggest that the log-transformed model may be a more versatile statistical approach to examining neuromuscular responses during dynamic exercise. PMID:25973471

  11. Real-time noninvasive optical imaging of exercising muscle and brain upon cognitive stimuli

    NASA Astrophysics Data System (ADS)

    Quaresima, Valentina; van der Sluijs, Marco C.; Menssen, Jan; Grillotti, Lucia; Ferrari, Marco; Colier, Willy N.

    2001-06-01

    The monitoring of a single muscle location does not reflect the heterogeneity of the muscle groups activation during exercise. In the past, measurements of oxygen consumption (VO2) at single muscle locations could be carried out non-invasively by near-infrared continuous wave spectroscopy (NIRCWS) at rest or during isometric contractions. In the present study, human regional quadriceps (vastus lateralis and rectus femoris) VO2 was investigated at rest and during maximal voluntary contractions using a 12- channel NIRCWS system with an acquisition time of 0.1 s.

  12. NMR based biomarkers to study age-related changes in the human quadriceps.

    PubMed

    Azzabou, Noura; Hogrel, Jean-Yves; Carlier, Pierre G

    2015-10-01

    Age-related sarcopenia is a major health issue. To improve elderly person quality of life, it is important to characterize age-associated structural changes within the skeletal muscle. NMR imaging offers quantitative tools to monitor these changes. We scanned 93 subjects: 33 young adults aged between 19 and 27 years old and 60 older adults between 69 and 80 years old. Their physical activity was assessed using a tri-axial accelerometer and they were classified either as active or sedentary. A standard multi-slice multi-echo (MSME) sequence was run and water T2 maps were extracted using a tri-exponential fit. Fat fraction was quantified using three-point Dixon technique. Each quadriceps muscle was characterized by: water T2 mean value, water T2 heterogeneity and the mean fat fraction. Statistical analysis (ANOVA) showed that water T2 mean values and its heterogeneity indices as well as fat fraction were significantly higher in the elderly group (p<0.05). Only fat fraction was significantly lower in the active group compared to the sedentary one (p<0.05). Linear regression confirmed the significant impact of age on these NMR parameters whereas physical activity impact was not systematic. NMR imaging provided a comprehensive assessment of the aging process impact on skeletal muscle composition. Water T2 increase might be related to changes in fiber typology while increased T2 heterogeneities might correlate with some degree of tissue disorganization, like the development of interstitial fibrosis. Fat fraction and water T2 heterogeneity increase was partly slowed down by physical activity. These changes were not gender dependent. PMID:26122131

  13. Bilateral Variability of the Quadriceps Angle (Q angle) in an Adult Indian Population

    PubMed Central

    Raveendranath, Raveendranath; Nachiket, Shankar; Sujatha, Narayanan; Priya, Ranganath; Rema, Devi

    2011-01-01

    Objective(s) The objective of this study was to document and explain bilateral differences in the Q angle. Materials and Methods Two hundred limbs of healthy adult Indian volunteers were studied. The Q angle was measured using a goniometric method with the subjects supine, quadriceps relaxed and lower limbs in neutral rotation. The relative lateral placement of the tibial tuberosity with respect to the centre of the patella was measured. Appropriate statistical tests were used to determine the bilateral variability in the Q angle and the lateral placement of the tibial tuberosity. Inter-observer variation of the above mentioned parameters were studied in twenty limbs. Results The average Q angle value of all the 200 limbs was 12.73 °C; the mean value on the right was 12.86 °C and 12.60 °C on the left. When the Q angle and the lateral placement of the tibial tuberosity were considered in pairs a significant difference was noted in males. The Q angle value on the right side was more often greater than the left. The relative lateral placement of the tibial tuberosity showed a significant positive correlation with the Q angle. The intra-class correlation coefficient was 0.66 for the Q angle and 0.8 for the lateral placement of the tibial tuberosity. Conclusion The present study shows that bilateral variability in the Q angle could be attributed to an alteration of the relative placement of the tibial tuberosity with respect to the centre of the patella. PMID:23493777

  14. Technical note: double tibial tunnel using quadriceps tendon in anterior cruciate ligament reconstruction.

    PubMed

    Pederzini, L; Adriani, E; Botticella, C; Tosi, M

    2000-07-01

    To avoid complications related to the use of patellar tendon and hamstring (semitendinosus and gracilis) tendon and to create a more anatomic reconstruction, we present a new technique based on the use of quadriceps tendon placed in a single half femoral tunnel and double tibial tunnels. The graft, harvested by a central longitudinal incision, possesses the following characteristics: (1) a bone plug 20 mm long and 10 mm in diameter; (2) a tendon component 7 to 8 cm long, 10 mm wide, and 8 mm thick; and (3) division of the tendon longitudinally into 2 bundles while maintaining the patellar insertion. Every bundle has a width and thickness of approximately 5 mm and 8 mm, respectively. The total length of the graft is 9 to 10 cm. A 10-mm half femoral tunnel is drilled through a low anteromedial portal with the knee flexed at 120 degrees. A suture loop is left in place in the half tunnel. A double tibial tunnel is drilled in a convergent manner (from outside to inside) obtaining an osseous bridge between the 2 tunnels. Two suture loops are passed trough the tibial tunnels and retrieved in a plastic cannula (10 mm) positioned in the anteromedial portal to allow the passage of the 2 bundles in the tibial tunnels. The suture loop left in the half tunnel permits the transportation of the bone plug in the femoral tunnel. Fixation is achieved by an interference screw at the femoral side and by 2 absorbable interference screws (1 for each tunnel). The advantages of this technique are a more cross-sectional area (80 mm(2)), greater bone-tendon interface, and a more anatomic reconstruction. Theoretically, easier bone incorporation, decreased windshield wiper and bungee effect, fewer donor site problems, and less tunnel enlargement can also be possible. PMID:10882460

  15. Analysis of three different equations for predicting quadriceps femoris muscle strength in patients with COPD *

    PubMed Central

    Nellessen, Aline Gonçalves; Donária, Leila; Hernandes, Nidia Aparecida; Pitta, Fabio

    2015-01-01

    Abstract Objective: To compare equations for predicting peak quadriceps femoris (QF) muscle force; to determine the agreement among the equations in identifying QF muscle weakness in COPD patients; and to assess the differences in characteristics among the groups of patients classified as having or not having QF muscle weakness by each equation. Methods: Fifty-six COPD patients underwent assessment of peak QF muscle force by dynamometry (maximal voluntary isometric contraction of knee extension). Predicted values were calculated with three equations: an age-height-weight-gender equation (Eq-AHWG); an age-weight-gender equation (Eq-AWG); and an age-fat-free mass-gender equation (Eq-AFFMG). Results: Comparison of the percentage of predicted values obtained with the three equations showed that the Eq-AHWG gave higher values than did the Eq-AWG and Eq-AFFMG, with no difference between the last two. The Eq-AHWG showed moderate agreement with the Eq-AWG and Eq-AFFMG, whereas the last two also showed moderate, albeit lower, agreement with each other. In the sample as a whole, QF muscle weakness (< 80% of predicted) was identified by the Eq-AHWG, Eq-AWG, and Eq-AFFMG in 59%, 68%, and 70% of the patients, respectively (p > 0.05). Age, fat-free mass, and body mass index are characteristics that differentiate between patients with and without QF muscle weakness. Conclusions: The three equations were statistically equivalent in classifying COPD patients as having or not having QF muscle weakness. However, the Eq-AHWG gave higher peak force values than did the Eq-AWG and the Eq-AFFMG, as well as showing greater agreement with the other equations. PMID:26398750

  16. Treadmill exercise induces neutrophil recruitment into muscle tissue in a reactive oxygen species-dependent manner. An intravital microscopy study.

    PubMed

    Nunes-Silva, Albená; Bernardes, Priscila T T; Rezende, Bárbara M; Lopes, Fernando; Gomes, Elisa C; Marques, Pedro E; Lima, Paulo M A; Coimbra, Cândido C; Menezes, Gustavo B; Teixeira, Mauro M; Pinho, Vanessa

    2014-01-01

    Intense exercise is a physiological stress capable of inducing the interaction of neutrophils with muscle endothelial cells and their transmigration into tissue. Mechanisms driving this physiological inflammatory response are not known. Here, we investigate whether production of reactive oxygen species is relevant for neutrophil interaction with endothelial cells and recruitment into the quadriceps muscle in mice subjected to the treadmill fatiguing exercise protocol. Mice exercised until fatigue by running for 56.3±6.8 min on an electric treadmill. Skeletal muscle was evaluated by intravital microscopy at different time points after exercise, and then removed to assess local oxidative stress and histopathological analysis. We observed an increase in plasma lactate and creatine kinase (CK) concentrations after exercise. The numbers of monocytes, neutrophils, and lymphocytes in blood increased 12 and 24 hours after the exercise. Numbers of rolling and adherent leukocytes increased 3, 6, 12, and 24 hours post-exercise, as assessed by intravital microscopy. Using LysM-eGFP mice and confocal intravital microscopy technology, we show that the number of transmigrating neutrophils increased 12 hours post-exercise. Mutant gp91phox-/- (non-functional NADPH oxidase) mice and mice treated with apocynin showed diminished neutrophil recruitment. SOD treatment promoted further adhesion and transmigration of leukocytes 12 hours after the exercise. These findings confirm our hypothesis that treadmill exercise increases the recruitment of leukocytes to the postcapillary venules, and NADPH oxidase-induced ROS plays an important role in this process. PMID:24798414

  17. Exercise-Induced Bronchoconstriction

    MedlinePLUS

    ... Conditions & Treatments ▸ Conditions Dictionary ▸ Exercise-Induced Bronchoconstriction Share | Exercise-Induced Bronchoconstriction (EIB) « Back to A to Z Listing Exercise-Induced Bronchoconstriction, (EIB), often known as exercise-induced ...

  18. Daily exercise routines

    NASA Technical Reports Server (NTRS)

    Anderson, Patrick L.; Amoroso, Michael T.

    1990-01-01

    Viewgraphs on daily exercise routines are presented. Topics covered include: daily exercise and periodic stress testings; exercise equipment; physiological monitors; exercise protocols; physiological levels; equipment control; control systems; and fuzzy logic control.

  19. The effects of trunk stability exercise and a combined exercise program on pain, flexibility, and static balance in chronic low back pain patients

    PubMed Central

    Hwangbo, Gak; Lee, Chae-Woo; Kim, Seong-Gil; Kim, Hyeon-Su

    2015-01-01

    [Purpose] The aim of this study was to examine the effect of trunk stability exercise and combined exercise program on pain, flexibility, and static balance in chronic low back pain patients. [Subjects and Methods] Thirty persons diagnosed with chronic low back pain were divided into a trunk stability exercise group and a combined exercise group and then conducted exercise for six weeks. [Results] VAS and sway lengths decreased significantly in both groups. A comparison of sway lengths after the intervention between the two groups revealed that the trunk stability exercise group had a bigger decrease than the combined exercise group. [Conclusion] The results of this study indicated that trunk stability exercise would have bigger effect than combined exercise on the daily activities of chronic low back pain patients as it strengthens deep abdominal muscles and improves flexibility and balancing ability. PMID:25995577

  20. Effect of Exercise Training and +Gz Acceleration Training on Men

    NASA Technical Reports Server (NTRS)

    Greenleaf, John E.; Simonson, Shawn R.; Stocks, Jodie M.; Evans, Joyce; Knapp, Charles F.; Cowell, Stephenie A.; Pemberton, Kendra N.; Wilson, Heather W.; Vener, Jamie M.; Evetts, Simon N.

    2001-01-01

    Countermeasures for reduction in work capacity (maximal oxygen uptake and strength) during spaceflight and enhanced orthostatic intolerance during re-entry, landing and egress from the return vehicle are continuing problems. The purpose for this study was to test the hypothesis that passive-acceleration training; supine, interval, exercise plus acceleration training and exercise combined with acceleration training would improve orthostatic tolerance in ambulatory men; and that addition of the aerobic exercise conditioning would not alter this improved tolerance from that of passive-acceleration training. Seven men (24-38 yr) underwent "Passive" training on the Ames human-powered centrifuge (HPC) for 30 min, "Exercise" training on the cycle ergometer with constant +Gz acceleration; and "Combined" exercise training at 40% to 90% of the HPC +Gz(max) exercise level. Maximal supine exercise loads increased significant (P<0.05) by 8.3% (Passive), 12.6% (Exercise), and by 15.4% (Combined) after training, but their post-training maximal oxygen uptakes and maximal heart rates were unchanged. Maximal time to fatigue (endurance) was unchanged with Passive was increased (P<0.05) with Exercise and Combined training. Thus, the exercise in the Exercise and Combined training Phases resulted in greater maximal loads and endurance without effect on maximal oxygen uptake or heart rate. There was a 4% to 6% increase (P<0.05) in all four quadriceps muscle volumes (right and left) after post-Combined training. Resting pre-tilt heart rate was elevated by 12.9% (P<0.05) only after Passive training suggesting that the exercise training attenuated the HR response. Plasma volume (% Delta) was uniformly decreased by 8% to 14% (P<0.05) at tilt-tolerance pre- vs. post-training indicating essentially no effect of training on the level of hypovolemia. Post-training tilt-tolerance time and heart rate were increased (P<0.05) only with Passive training by 37.8% and by 29.1%, respectively. Thus, addition of exercise training appeared to attenuate the increased Passive tilt-tolerance.

  1. The effect of ageing in spinal cord injured humans on the blood pressure and heart rate responses during fatiguing isometric exercise.

    PubMed

    Petrofsky, Jerrold Scott; Laymon, Michael

    2002-04-01

    Groups of 50 healthy male controls and 50 subjects suffering from paraplegia (aged 20-65 years) were examined as to the inter-relationships between age, paraplegia and the strength, endurance, blood pressure and heart rate responses to fatiguing isometric exercise. Contractions were maintained in both groups under voluntary effort and through a contraction induced by electrical stimulation in the paraplegic group. All contractions were maintained to fatigue at a tension of 40% of the maximal muscle strength in either the handgrip or quadriceps muscles. Muscle strength of the handgrip was higher in the paraplegic subjects than in the controls, averaging 589 N and 463 N, respectively for the two groups. In contrast, quadriceps leg extension strength averaged 696 N in the controls and 190 N in the paraplegic groups; for both groups, ageing was associated with a reduction in muscle strength. While leg endurance was less in the paraplegic group than the control group, handgrip endurance was similar in the two groups, endurance increasing with ageing in both the controls and paraplegics. Both systolic and diastolic blood pressures increased at rest in paraplegic and control subjects with age. The magnitude of the pressor response to exercise also increased with age. This was true during both voluntary exercise and exercise induced through electrical stimulation in the paraplegic groups. The heart rate response (change in heart rate during exercise) to a fatiguing isometric handgrip contraction decreased by about 50% between the ages of 20 and 60 years in both the controls and paraplegics for isometric handgrip exercise. In contrast, heart rate changed little with age during contractions of the quadriceps muscle in paraplegics which were induced by electrical stimulation. PMID:11944094

  2. Angle-specific hamstring-to-quadriceps ratio: a comparison of football players and recreationally active males.

    PubMed

    Evangelidis, Pavlos Eleftherios; Pain, Matthew Thomas Gerard; Folland, Jonathan

    2015-01-01

    It is currently unclear how football participation affects knee-joint muscle balance, which is widely considered a risk factor for hamstrings injury. This study compared the angle-specific functional hamstring-to-quadriceps (H:Q) ratio (hamstrings eccentric torque as a ratio of quadriceps concentric torque at the same knee-joint angle) of football players with recreationally active controls. Ten male footballers and 14 controls performed maximal voluntary isometric and isovelocity concentric and eccentric contractions (60, 240 and 400° s(-1)) of the knee extensors and flexors. Gaussian fitting to the raw torque values was used to interpolate torque values for knee-joint angles of 100-160° (60° s(-1)), 105-160° (240° s(-1)) and 115-145° (400° s(-1)). The angle-specific functional H:Q ratio was calculated from the knee flexors eccentric and knee extensors concentric torque at the same velocity and angle. No differences were found for the angle-specific functional H:Q ratio between groups, at any velocity. Quadriceps and hamstrings strength relative to body mass of footballers and controls was similar for all velocities, except concentric knee flexor strength at 400° s(-1) (footballers +40%; P < 0.01). In previously uninjured football players, there was no intrinsic muscle imbalance and therefore the high rate of hamstring injuries seen in this sport may be due to other risk factors and/or simply regular exposure to a high-risk activity. PMID:25073098

  3. AMPK? is essential for acute exercise-induced gene responses but not for exercise training-induced adaptations in mouse skeletal muscle.

    PubMed

    Fentz, Joachim; Kjbsted, Rasmus; Kristensen, Caroline Maag; Hingst, Janne Rasmus; Birk, Jesper Bratz; Gudiksen, Anders; Foretz, Marc; Schjerling, Peter; Viollet, Benoit; Pilegaard, Henriette; Wojtaszewski, Jrgen F P

    2015-12-01

    Exercise training increases skeletal muscle expression of metabolic proteins improving the oxidative capacity. Adaptations in skeletal muscle by pharmacologically induced activation of 5'-AMP-activated protein kinase (AMPK) are dependent on the AMPK?2 subunit. We hypothesized that exercise training-induced increases in exercise capacity and expression of metabolic proteins, as well as acute exercise-induced gene regulation, would be compromised in muscle-specific AMPK?1 and -?2 double-knockout (mdKO) mice. An acute bout of exercise increased skeletal muscle mRNA content of cytochrome c oxidase subunit I, glucose transporter 4, and VEGF in an AMPK-dependent manner, whereas cluster of differentiation 36 and fatty acid transport protein 1 mRNA content increased similarly in AMPK? wild-type (WT) and mdKO mice. During 4 wk of voluntary running wheel exercise training, the AMPK? mdKO mice ran less than WT. Maximal running speed was lower in AMPK? mdKO than in WT mice but increased similarly in both genotypes with exercise training. Exercise training increased quadriceps protein content of ubiquinol-cytochrome c reductase core protein 1 (UQCRC1), cytochrome c, hexokinase II, plasma membrane fatty acid-binding protein, and citrate synthase activity more in AMPK? WT than in mdKO muscle. However, analysis of a subgroup of mice matched for running distance revealed that only UQCRC1 protein content increased more in WT than in mdKO mice with exercise training. Thus, AMPK?1 and -?2 subunits are important for acute exercise-induced mRNA responses of some genes and may be involved in regulating basal metabolic protein expression but seem to be less important in exercise training-induced adaptations in metabolic proteins. PMID:26419588

  4. [Exercise addiction].

    PubMed

    Petit, A; Lejoyeux, M

    2013-01-01

    Socially valorised, sport like other forms of behaviour, can take on an addictive aspect. A review of the English and French literatures from 1979 to 2012 was conducted, using PubMed, Google Scholar, EMBASE, and PsycInfo, using the following key words alone or combined :sport, dependence, exercise, addiction. Exercise dependence is defined as a craving for physical activity that leads to extreme exercise intensity and generates physiological and psychological symptoms. Measurement scales have been proposed to make the diagnosis. No epidemiological studies have examined the prevalence of exercise dependence in the general population, although some studies suggest a frequency ranging from 10 to 80%. Disorders begin with a search for pleasure in physical effort, which then gives way to an obsession for sport resulting in a need to practice a sport more and more frequently and intensely. This addiction is more common among alcohol and illicit drug addicts than among the general population, while the rate of eating disorders can reach 40%. Personality traits most often associated are perfectionism, extraversion, and sensation seeking, while possible links between sporting activity and intensive doping will be discussed. PMID:23888586

  5. Exercise apparatus

    NASA Technical Reports Server (NTRS)

    Schaffner, Grant (Inventor); Bentley, Jason R. (Inventor); Loehr, James A. (Inventor); Gundo, Daniel P. (Inventor)

    2006-01-01

    An apparatus and method for exercising whereby the user is supported by various mechanisms in such as way that the user's shoulder area is free to translate and rotate; the user's pelvic area is free to translate and rotate; or in any combination.

  6. Rapid Hamstrings/Quadriceps Strength Capacity in Professional Soccer Players with Different Conventional Isokinetic Muscle Strength Ratios

    PubMed Central

    Greco, Camila C.; Da Silva, Wendell L.; Camarda, Sérgio R.A.; Denadai, Benedito S.

    2012-01-01

    Muscle strength imbalance can be an important factor in hamstrings muscle strain. A hamstrings/quadriceps (H/Q) strength ratio based on concentric peak torque values (Hcon:Qcon) has traditionally been used to describe the potential for knee-joint destabilization. Because certain standard actions in soccer are explosive, the analysis of the H/Q strength ratio based on the rate of torque development (Hrtd:Qrtd) might also be useful in the evaluation of joint stability. The objective of this study was to compare the Hrtd:Qrtd between professional soccer players with heterogeneous values of Hcon:Qcon. Thirty-nine professional soccer players took part in the following procedures on different days: 1) Familiarization session with the isokinetic dynamometer, and 2) Two maximal isometric actions and five maximal concentric actions at 60°·s-1 for hamstrings (H) and quadriceps (Q). Participants were ranked according to their Hcon:Qcon ratio. The median third was excluded to form a high torque group (HTG), and a low torque group (LTG). Peak isometric (H) and concentric (H and Q) torques and rate of torque development (H) were significantly greater in the HTG group. Similarly, Hcon:Qcon (0.68 ± 0.02 vs. 0.52 ± 0.03) and Hrtd:Qrtd (0.54 ± 0.12 vs. 0.43 ± 0.16) were significantly greater in the HTG group than in the LTG group. There was no significant correlation between Hcon:Qcon and Hrtd:Qrtd. It can be concluded that Hcon:Qcon and Hrtd:Qrtd are determined, but not fully defined, by shared putative physiological mechanisms. Thus, the physiologic and clinical significance of Hcon:Qcon and Hrtd:Qrtd to an athlete’s individual evaluation might be different. Key pointsSoccer players with high (0.66-0.70) and low (0.50-0.54) conventional concentric hamstrings:quadriceps ratios (Hcon:Qcon) tend to demonstrate similar profiles (i.e., high and low, respectively) in their rate of the torque development H/Q ratio (Hrtd:Qrtd).The lack of a significant relationship between Hcon:Qcon and Hrtd:Qrtd suggests that these ratios are determined, but not fully defined, by shared putative physiological mechanisms.Preseason screening programs that monitor hamstrings:quadriceps ratios should recognize that the physiologic and clinical significance of Hcon:Qcon and Hrfd:Qrfd to an athlete’s individual evaluation might be different. PMID:24149348

  7. Transcriptome Analysis in Venom Gland of the Predatory Giant Ant Dinoponera quadriceps: Insights into the Polypeptide Toxin Arsenal of Hymenopterans

    PubMed Central

    Chong, Cheong-Meng; Leung, Siu Wai; Prieto-da-Silva, Álvaro R. B.; Havt, Alexandre; Quinet, Yves P.; Martins, Alice M. C.; Lee, Simon M. Y.; Rádis-Baptista, Gandhi

    2014-01-01

    Background Dinoponera quadriceps is a predatory giant ant that inhabits the Neotropical region and subdues its prey (insects) with stings that deliver a toxic cocktail of molecules. Human accidents occasionally occur and cause local pain and systemic symptoms. A comprehensive study of the D. quadriceps venom gland transcriptome is required to advance our knowledge about the toxin repertoire of the giant ant venom and to understand the physiopathological basis of Hymenoptera envenomation. Results We conducted a transcriptome analysis of a cDNA library from the D. quadriceps venom gland with Sanger sequencing in combination with whole-transcriptome shotgun deep sequencing. From the cDNA library, a total of 420 independent clones were analyzed. Although the proportion of dinoponeratoxin isoform precursors was high, the first giant ant venom inhibitor cysteine-knot (ICK) toxin was found. The deep next generation sequencing yielded a total of 2,514,767 raw reads that were assembled into 18,546 contigs. A BLAST search of the assembled contigs against non-redundant and Swiss-Prot databases showed that 6,463 contigs corresponded to BLASTx hits and indicated an interesting diversity of transcripts related to venom gene expression. The majority of these venom-related sequences code for a major polypeptide core, which comprises venom allergens, lethal-like proteins and esterases, and a minor peptide framework composed of inter-specific structurally conserved cysteine-rich toxins. Both the cDNA library and deep sequencing yielded large proportions of contigs that showed no similarities with known sequences. Conclusions To our knowledge, this is the first report of the venom gland transcriptome of the New World giant ant D. quadriceps. The glandular venom system was dissected, and the toxin arsenal was revealed; this process brought to light novel sequences that included an ICK-folded toxins, allergen proteins, esterases (phospholipases and carboxylesterases), and lethal-like toxins. These findings contribute to the understanding of the ecology, behavior and venomics of hymenopterans. PMID:24498135

  8. The effect of mild symptomatic patellar tendinopathy on the quadriceps contractions and the Fente motion in elite fencers

    PubMed Central

    Kim, Taegyu; Kim, Eunkuk; Park, Jongchul; Kang, Hyunyong

    2011-01-01

    To investigate how mild symptomatic patellar tendinopathy (PT) affects quadriceps contractions and the Fente motion, this case-control study examined elite fencers who continue to train and play fully with mild tendon pains. Twenty-four elite fencers (10 women) with mild symptomatic PT and 24 controls (10 women) participated in the study. Concentric/eccentric isokinetic strength of the quadriceps was tested, and peak torque and total work were recorded. Kinematic data from the knee during the Fente motion were collected. The first analysis period (P1) was after heel contact to the maximal flexion of the knee, and the second (P2) was right after P1 to heel-off. Normalized peak torque and work of concentric/eccentric contractions were not significantly different. Affected fencers demonstrated significantly reduced angular velocities at P2 (p = 0.042). The male fencers did not demonstrate any differences. The affected female fencers demonstrated significantly weaker concentric peak torque at 60°·s-1 (p = 0. 009) and 180°·s-1 (p = 0.047) and less concentric work at 60°·s-1 (p = 0.020). They also demonstrated significantly reduced average angular velocities at P2 (p = 0.001). Therefore, mild symptomatic PT seems to have an effect on the isokinetic concentric contraction of the quadriceps and the angular velocity of the knee during the backward Fente motion in elite female fencers who are participating fully in training and competition. Key points It is likely that even mild symptomatic patellar tendinopathy could affect the athletic performances in elite fencers. Elite female fencers are more likely to be affected substantially by symptomatic patellar tendinopathy in their sporting ability than male fencers. Because weak concentric knee extensors may affect the performance in fencing, not only eccentric training for symptomatic patellar tendinopathy but also proper concentric training of the quadriceps may be helpful in a rehabilitation program of elite female fencers who are participating fully in their training and competition. PMID:24149561

  9. Exercise Hypertension.

    PubMed

    Schultz, Martin G; Sharman, James E

    2014-05-01

    Irrespective of apparent 'normal' resting blood pressure (BP), some individuals may experience an excessive elevation in BP with exercise (i.e. systolic BP ?210 mm Hg in men or ?190 mm Hg in women or diastolic BP ?110 mm Hg in men or women), a condition termed exercise hypertension or a 'hypertensive response to exercise' (HRE). An HRE is a relatively common condition that is identified during standard exercise stress testing; however, due to a lack of information with respect to the clinical ramifications of an HRE, little value is usually placed on such a finding. In this review, we discuss both the clinical importance and underlying physiological contributors of exercise hypertension. Indeed, an HRE is associated with an increased propensity for target organ damage and also predicts the future development of hypertension, cardiovascular events and mortality, independent of resting BP. Moreover, recent work has highlighted that some of the elevated cardiovascular risks associated with an HRE may be related to high-normal resting BP (pre-hypertension) or ambulatory 'masked' hypertension and that an HRE may be an early warning signal of abnormal BP control that is otherwise undetected with clinic BP. Whilst an HRE may be amenable to treatment via pharmacological and lifestyle interventions, the exact physiological mechanism of an HRE remains elusive, but it is likely a manifestation of multiple factors including large artery stiffness, increased peripheral resistance, neural circulatory control and metabolic irregularity. Future research focus may be directed towards determining threshold values to denote the increased risk associated with an HRE and further resolution of the underlying physiological factors involved in the pathogenesis of an HRE. PMID:26587435

  10. Exercise Hypertension

    PubMed Central

    Schultz, Martin G.; Sharman, James E.

    2014-01-01

    Irrespective of apparent ‘normal' resting blood pressure (BP), some individuals may experience an excessive elevation in BP with exercise (i.e. systolic BP ≥210 mm Hg in men or ≥190 mm Hg in women or diastolic BP ≥110 mm Hg in men or women), a condition termed exercise hypertension or a ‘hypertensive response to exercise' (HRE). An HRE is a relatively common condition that is identified during standard exercise stress testing; however, due to a lack of information with respect to the clinical ramifications of an HRE, little value is usually placed on such a finding. In this review, we discuss both the clinical importance and underlying physiological contributors of exercise hypertension. Indeed, an HRE is associated with an increased propensity for target organ damage and also predicts the future development of hypertension, cardiovascular events and mortality, independent of resting BP. Moreover, recent work has highlighted that some of the elevated cardiovascular risks associated with an HRE may be related to high-normal resting BP (pre-hypertension) or ambulatory ‘masked' hypertension and that an HRE may be an early warning signal of abnormal BP control that is otherwise undetected with clinic BP. Whilst an HRE may be amenable to treatment via pharmacological and lifestyle interventions, the exact physiological mechanism of an HRE remains elusive, but it is likely a manifestation of multiple factors including large artery stiffness, increased peripheral resistance, neural circulatory control and metabolic irregularity. Future research focus may be directed towards determining threshold values to denote the increased risk associated with an HRE and further resolution of the underlying physiological factors involved in the pathogenesis of an HRE. PMID:26587435

  11. Current ISS Exercise Countermeasures: Where are we now?

    NASA Technical Reports Server (NTRS)

    Hayes, J. C.; Loerch, L.; Davis-Street, J.; Haralson, Cortni; Sams, C.

    2006-01-01

    Current International Space Station (ISS) crew schedules include 1.5 h/d for completion of resistive exercise and 1 h/d of aerobic exercise , 6 d/wk. While ISS post flight decrements in muscle strength, bone m ineral density, and aerobic capacity improved in some crewmembers, de conditioning was still evident even with this volume of exercise. Res ults from early ISS expeditions show maximum loss in bone mineral density of the lumbar spine and pelvis in excess of 1.5% per month, with all crewmembers demonstrating significant bone loss in one or more re gions. Similarly, post flight muscle strength losses in the hamstring and quadriceps muscle groups exceeded 30% in the immediate post miss ion period in some crewmembers. Measures of aerobic capacity early in the mission show average decrements of 15%, but with onboard aerobic exercise capability, the crew has been able to "train up" over the co urse of the mission. These findings are highly variable among crewmem bers and appear to be correlated with availability and reliability of the inflight resistive exercise device (RED), cycle ergometer, and t readmill. This suite of hardware was installed on ISS with limited op erational evaluation in groundbased test beds. As a result, onorbit hardware constraints have resulted in inadequate physical stimulus, d econditioning, and increased risk for compromised performance during intra and extravehicular activities. These issues indicate that the c urrent ISS Countermeasures System reliability or validity are not ade quate for extendedduration exploration missions. Learning Objective: A better understanding of the status of ISS exercise countermeasures , their ability to protect physiologic systems, and recommendations for exploration exercise countermeasures.

  12. 27 CFR 24.153 - Strengthening bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Strengthening bonds. 24.153 Section 24.153 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Establishment and Operations Bonds and Consents of Surety § 24.153 Strengthening bonds. In any instance...

  13. 27 CFR 44.245 - Strengthening bond.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2014-04-01 2014-04-01 false Strengthening bond. 44.245..., WITHOUT PAYMENT OF TAX, OR WITH DRAWBACK OF TAX Withdrawal of Cigars From Customs Warehouses Bonds § 44.245 Strengthening bond. Where the appropriate TTB officer determines that the amount of the...

  14. 27 CFR 24.153 - Strengthening bonds.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Strengthening bonds. 24..., DEPARTMENT OF THE TREASURY ALCOHOL WINE Establishment and Operations Bonds and Consents of Surety § 24.153 Strengthening bonds. In any instance where the penal sum of the bond on file becomes insufficient, the...

  15. 27 CFR 44.245 - Strengthening bond.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2013-04-01 2013-04-01 false Strengthening bond. 44.245..., WITHOUT PAYMENT OF TAX, OR WITH DRAWBACK OF TAX Withdrawal of Cigars From Customs Warehouses Bonds § 44.245 Strengthening bond. Where the appropriate TTB officer determines that the amount of the...

  16. 27 CFR 41.122 - Strengthening bond.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2014-04-01 2014-04-01 false Strengthening bond. 41.122... States Deferred Payment of Tax in Puerto Rico on Tobacco Products § 41.122 Strengthening bond. Where the amount of any bond is no longer sufficient under the provisions of § 41.121, the bonded...

  17. 27 CFR 24.153 - Strengthening bonds.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Strengthening bonds. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Establishment and Operations Bonds and Consents of Surety § 24.153 Strengthening bonds. In any instance where the penal sum of the bond on file becomes insufficient, the...

  18. 27 CFR 44.124 - Strengthening bond.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2014-04-01 2014-04-01 false Strengthening bond. 44.124..., WITHOUT PAYMENT OF TAX, OR WITH DRAWBACK OF TAX Bonds and Extensions of Coverage of Bonds § 44.124 Strengthening bond. Where the appropriate TTB officer determines that the amount of the bond, under which...

  19. 27 CFR 40.135 - Strengthening bond.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2012-04-01 2011-04-01 true Strengthening bond. 40.135... PROCESSED TOBACCO Bonds and Extensions of Coverage of Bonds § 40.135 Strengthening bond. Where the amount of any bond is no longer sufficient under the provisions of § 40.133 or § 40.134, the manufacturer...

  20. 27 CFR 44.124 - Strengthening bond.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2012-04-01 2011-04-01 true Strengthening bond. 44.124..., WITHOUT PAYMENT OF TAX, OR WITH DRAWBACK OF TAX Bonds and Extensions of Coverage of Bonds § 44.124 Strengthening bond. Where the appropriate TTB officer determines that the amount of the bond, under which...

  1. 27 CFR 40.135 - Strengthening bond.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2014-04-01 2014-04-01 false Strengthening bond. 40.135... PROCESSED TOBACCO Bonds and Extensions of Coverage of Bonds § 40.135 Strengthening bond. Where the amount of any bond is no longer sufficient under the provisions of § 40.133 or § 40.134, the manufacturer...

  2. 27 CFR 28.66 - Strengthening bonds.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Strengthening bonds. 28.66... OF THE TREASURY ALCOHOL EXPORTATION OF ALCOHOL Bonds and Consents of Surety § 28.66 Strengthening bonds. In all cases where the penal sum of any bond becomes insufficient, the principal shall...

  3. 27 CFR 44.124 - Strengthening bond.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2013-04-01 2013-04-01 false Strengthening bond. 44.124..., WITHOUT PAYMENT OF TAX, OR WITH DRAWBACK OF TAX Bonds and Extensions of Coverage of Bonds § 44.124 Strengthening bond. Where the appropriate TTB officer determines that the amount of the bond, under which...

  4. 27 CFR 40.135 - Strengthening bond.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2013-04-01 2013-04-01 false Strengthening bond. 40.135... PROCESSED TOBACCO Bonds and Extensions of Coverage of Bonds § 40.135 Strengthening bond. Where the amount of any bond is no longer sufficient under the provisions of § 40.133 or § 40.134, the manufacturer...

  5. 27 CFR 41.122 - Strengthening bond.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2013-04-01 2013-04-01 false Strengthening bond. 41.122... States Deferred Payment of Tax in Puerto Rico on Tobacco Products § 41.122 Strengthening bond. Where the amount of any bond is no longer sufficient under the provisions of § 41.121, the bonded...

  6. 27 CFR 28.66 - Strengthening bonds.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Strengthening bonds. 28.66... OF THE TREASURY LIQUORS EXPORTATION OF ALCOHOL Bonds and Consents of Surety § 28.66 Strengthening bonds. In all cases where the penal sum of any bond becomes insufficient, the principal shall...

  7. 27 CFR 44.245 - Strengthening bond.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2012-04-01 2011-04-01 true Strengthening bond. 44.245..., WITHOUT PAYMENT OF TAX, OR WITH DRAWBACK OF TAX Withdrawal of Cigars From Customs Warehouses Bonds § 44.245 Strengthening bond. Where the appropriate TTB officer determines that the amount of the...

  8. 27 CFR 41.122 - Strengthening bond.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2012-04-01 2011-04-01 true Strengthening bond. 41.122... States Deferred Payment of Tax in Puerto Rico on Tobacco Products § 41.122 Strengthening bond. Where the amount of any bond is no longer sufficient under the provisions of § 41.121, the bonded...

  9. Strengthening mechanisms of tungsten powder reinforced uranium

    SciTech Connect

    Krawizcki, M.A.

    1990-04-01

    Tungsten powder reinforced uranium composites exhibit a three-fold increase in yield strength due to precipitation hardening. The tungsten-rich interphase precipitates form at the moving beta to alpha phase boundary during slow cooling. Further increases in yield strength, attained with increasing tungsten content, are due to composite strengthening. The composite strengthening is verified by increasing elastic modulus with increasing tungsten content. Age hardening behavior is observed, with strengthening occurring at aging temperatures low, in the alpha phase. Temperatures higher in alpha give initial strengthening followed by rapid overaging. Beta phase aging temperatures result in a very soft structure with interphase precipitates observable optically. Wrought material exhibits significant strain hardening as well as composite strengthening due to elongation of the tungsten particles. 36 refs., 36 figs., 10 tabs.

  10. Exercise Prescriptions to Prevent Musculoskeletal Disorders in Dentists

    PubMed Central

    Kumar, Dodda Kiran; Mohan, Sreevalli; Begum, Mohammadi; Prasad, Bhanu; Prasad, Eswar Ravi Vara

    2014-01-01

    Since the number of dental patients is increasing day by day dentists are forced to spend longer times in dental chairs. This is increasing the prevalence of musculoskeletal disorders in dentists. This article reviews the mechanisms causing musculoskeletal disorders among dentists and also covers the exercises that can be done to prevent them. Exercises that increase the fitness of a dentist are divided into aerobic exercises – concentrating on total body fitness, stretching exercises – that concentrate on the muscles that tend to tighten in prolonged dental postures and strengthening exercises – that concentrate on the muscles that are opposite to the tight muscles. These exercises are made simple and of minimal intensity so that a dentist can practice them independently. PMID:25177661

  11. Exercise prescriptions to prevent musculoskeletal disorders in dentists.

    PubMed

    Kumar, Dodda Kiran; Rathan, Neelima; Mohan, Sreevalli; Begum, Mohammadi; Prasad, Bhanu; Prasad, Eswar Ravi Vara

    2014-07-01

    Since the number of dental patients is increasing day by day dentists are forced to spend longer times in dental chairs. This is increasing the prevalence of musculoskeletal disorders in dentists. This article reviews the mechanisms causing musculoskeletal disorders among dentists and also covers the exercises that can be done to prevent them. Exercises that increase the fitness of a dentist are divided into aerobic exercises - concentrating on total body fitness, stretching exercises - that concentrate on the muscles that tend to tighten in prolonged dental postures and strengthening exercises - that concentrate on the muscles that are opposite to the tight muscles. These exercises are made simple and of minimal intensity so that a dentist can practice them independently. PMID:25177661

  12. Knee and Hip Joint Kinematics Predict Quadriceps and Hamstrings Neuromuscular Activation Patterns in Drop Jump Landings

    PubMed Central

    Malfait, Bart; Dingenen, Bart; Smeets, Annemie; Staes, Filip; Pataky, Todd; Robinson, Mark A.; Vanrenterghem, Jos; Verschueren, Sabine

    2016-01-01

    Purpose The purpose was to assess if variation in sagittal plane landing kinematics is associated with variation in neuromuscular activation patterns of the quadriceps-hamstrings muscle groups during drop vertical jumps (DVJ). Methods Fifty female athletes performed three DVJ. The relationship between peak knee and hip flexion angles and the amplitude of four EMG vectors was investigated with trajectory-level canonical correlation analyses over the entire time period of the landing phase. EMG vectors consisted of the {vastus medialis(VM),vastus lateralis(VL)}, {vastus medialis(VM),hamstring medialis(HM)}, {hamstring medialis(HM),hamstring lateralis(HL)} and the {vastus lateralis(VL),hamstring lateralis(HL)}. To estimate the contribution of each individual muscle, linear regressions were also conducted using one-dimensional statistical parametric mapping. Results The peak knee flexion angle was significantly positively associated with the amplitudes of the {VM,HM} and {HM,HL} during the preparatory and initial contact phase and with the {VL,HL} vector during the peak loading phase (p<0.05). Small peak knee flexion angles were significantly associated with higher HM amplitudes during the preparatory and initial contact phase (p<0.001). The amplitudes of the {VM,VL} and {VL,HL} were significantly positively associated with the peak hip flexion angle during the peak loading phase (p<0.05). Small peak hip flexion angles were significantly associated with higher VL amplitudes during the peak loading phase (p = 0.001). Higher external knee abduction and flexion moments were found in participants landing with less flexed knee and hip joints (p<0.001). Conclusion This study demonstrated clear associations between neuromuscular activation patterns and landing kinematics in the sagittal plane during specific parts of the landing. These findings have indicated that an erect landing pattern, characterized by less hip and knee flexion, was significantly associated with an increased medial and posterior neuromuscular activation (dominant hamstrings medialis activity) during the preparatory and initial contact phase and an increased lateral neuromuscular activation (dominant vastus lateralis activity) during the peak loading phase. PMID:27101130

  13. Core muscle strengthening's improvement of balance performance in community-dwelling older adults: a pilot study.

    PubMed

    Kahle, Nicole; Tevald, Michael A

    2014-01-01

    To determine the effect of core muscle strengthening on balance in community-dwelling older adults, 24 healthy men and women between 65 and 85 years old were randomized to either exercise (EX; n = 12) or control (CON; n = 12) groups. The exercise group performed a core strengthening home exercise program thrice weekly for 6 wk. Core muscle (curl-up test), functional reach (FR) and Star Excursion Balance Test (SEBT) were assessed at baseline and follow-up. There were no group differences at baseline. At follow-up, EX exhibited significantly greater improvements in curl-up (Cohen's d = 4.4), FR (1.3), and SEBT (>1.9 for all directions) than CON. The change in curl-up was significantly correlated with the change in FR (r = .44, p = .03) and SEBT (r > .61, p ≤ .002). These results suggest that core strengthening should be part of a comprehensive balance-training program for older adults. PMID:23348043

  14. The combined effect of cycling cadence and crank resistance on hamstrings and quadriceps muscle activities during cycling.

    PubMed

    Katona, P; Pilissy, T; Tihanyi, A; Laczkó, József

    2014-12-01

    The effect of cycling cadence and crank resistance on the activity of hamstrings and quadriceps muscles was investigated during cycling movements of able-bodied subjects on a stationary bike with slow and fast speed against different resistance conditions. The ratio of average EMG amplitudes obtained in the two speed conditions (fast/slow) was computed in each resistance condition. This ratio is higher for both muscles if cycling against higher resistance. This shows that in higher resistance condition muscle activities are not only increased but the change of muscle activities with respect to cadence change varied according to resistance condition. Average EMG amplitudes increased at a higher rate with respect to change of cadence when cycling was performed in higher resistance condition. Besides, when cycling faster, hamstrings activity increased generally at a higher rate than that of quadriceps. The correlation between cadence and EMG amplitudes were also investigated. Considering hamstrings, this correlation was low and decreased as resistance increased. The correlation between the time required to drive one cycle and EMG amplitude is negative but in absolute value it is larger than the correlation of cadence and EMG amplitude. PMID:25532958

  15. Isokinetic strength of the quadriceps and hamstrings and functional ability of anterior cruciate deficient knees in recreational athletes.

    PubMed Central

    Li, R C; Maffulli, N; Hsu, Y C; Chan, K M

    1996-01-01

    OBJECTIVE: To test the hypothesis that increasing the hamstrings and quadriceps (H:Q) isokinetic strength ratio will, in the short term, improve the functional ability of an anterior cruciate ligament (ACL) deficient knee. METHODS: The isokinetic muscular characteristics at a speed of 60 degrees s-1 and 180 degrees s-1 of 46 recreational athletes with an arthroscopically confirmed ACL tear were determined using the Cybex II+ isokinetic dynamometer. The variables tested included peak torque, endurance ratio, total work output, and explosive power. Functional ability was scored with the Cincinnati rating system, measuring the severity of pain and swelling, the degree of giving way, and the overall ability to walk, run, ascent and descent stairs, jump and twist. RESULTS: Among all muscular characteristics, the H:Q ratio at 180 degrees s-1 at 30 degrees of knee flexion was shown to have the highest correlation to the functional score (r = 0.6249, P < 0.001). All variables involving hamstring strength were shown to be significantly correlated to the functional ability score (P < 0.01), while none of the variables involving quadriceps strength showed significant correlation with the functional ability of the injured knee. CONCLUSIONS: The H:Q ratio is strongly correlated to the functional ability of ACL deficient knees in Chinese recreational athletes. It could be used as an additional measure to guide in the decision making process in the management of ACL deficient knees. PMID:8799604

  16. Testing a model of post-stroke exercise behavior.

    PubMed

    Shaughnessy, Marianne; Resnick, Barbara M; Macko, Richard F

    2006-01-01

    Stroke is the leading cause of disability in older Americans, and survivors tend to be sedentary, thereby risking loss of functional gains achieved during rehabilitation and increasing cardiovascular risk. Studies of motivation to exercise in older adults suggest that self-efficacy and outcome expectations are key determinants of initiation and adherence to exercise programs. This study tested a theoretical model of physical activity in stroke survivors. A survey of exercise beliefs and patterns was sent to National Stroke Association stroke support groups. Responses from 312 stroke survivors (mean age 63 years, 57% female, 70% White) indicated that only 31% exercised four times weekly. Self-efficacy and outcome expectations for exercise, before exercise history, and physician recommendation all directly and indirectly influenced self-reported exercise behavior and accounted for 33% of the total variance in exercise behavior. Model testing supported the theory and the model fit the data. Interventions to strengthen self-efficacy and outcome expectations for exercise, along with reminders for clinicians to encourage regular exercise programs, may increase the likelihood of initiating and maintaining an exercise program, potentially improving physical function and cardiovascular fitness in this population. PMID:16422040

  17. HIV communication capacity strengthening: a critical review.

    PubMed

    Lettenmaier, Cheryl; Kraft, Joan Marie; Raisanen, Keris; Serlemitsos, Elizabeth

    2014-08-15

    HIV communication is most effective and sustainable when it is designed and implemented locally and tailored to the local context. This requires capacity strengthening at national, subnational, and community levels. Through a review of the published and selected "grey" literature, we examine HIV communication capacity strengthening: definitions, measurements, implementation, and effects. We found limited documentation of HIV communication capacity needs or systematic approaches to address them. Most HIV communication capacity strengthening to date has focused on building individual competencies to design and manage social and behavior change communication programs through training courses, often coupled with networking opportunities for participants, post-training mentoring, and technical assistance. A few of these efforts have been evaluated through pre- and post-training tests and qualitative interviews with participants and have shown potential for improvement in individual skills and knowledge. Health communication capacity assessment tools that measure individual and organizational competencies exist, but they have most often been used to identify capacity building needs, not for evaluating capacity strengthening efforts. A new definition of capacity strengthening, grown out of recent efforts to improve effectiveness of international health and development programs, focuses on improving organizational and societal systems that support performance and individual competencies. We propose a holistic model for HIV communication capacity strengthening and call for rigorous documentation and evaluation to determine and scale-up optimal capacity building interventions for strengthening social and behavior change communication for HIV prevention, care, and treatment in developing countries. PMID:25007200

  18. Muscular adaptations to fatiguing exercise with and without blood flow restriction.

    PubMed

    Fahs, Christopher A; Loenneke, Jeremy P; Thiebaud, Robert S; Rossow, Lindy M; Kim, Daeyeol; Abe, Takashi; Beck, Travis W; Feeback, Daniel L; Bemben, Debra A; Bemben, Michael G

    2015-05-01

    The purpose of this study was to determine the muscular adaptations to low-load resistance training performed to fatigue with and without blood flow restriction (BFR). Middle-aged (42-62 years) men (n = 12) and women (n = 6) completed 18 sessions of unilateral knee extensor resistance training to volitional fatigue over 6 weeks. One limb trained under BFR, and the contralateral limb trained without BFR [free flow (FF)]. Before and after the training, measures of anterior and lateral quadriceps muscle thickness (MTh), strength, power and endurance were assessed on each limb. The total exercise training volume was significantly greater for the FF limb compared with the BFR limb (P<0·001). Anterior quadriceps thickness and muscle function increased following the training in each limb with no differences between limbs. Lateral quadriceps MTh increased significantly more (P<0·05) in the limb trained under BFR (BFR: 3·50 ± 0·61 to 3·67 ± 0·62 cm; FF: 3·49 ± 0·73 to 3·56 ± 0·70 cm). Low-load resistance training to volitional fatigue both with and without BFR is viable options for improving muscle function in middle-aged individuals. However, BFR enhanced the hypertrophic effect of low-load training and reduced the volume of exercise needed to elicit increases in muscle function. PMID:24612120

  19. Acute exercise induced mitochondrial H₂O₂ production in mouse skeletal muscle: association with p(66Shc) and FOXO3a signaling and antioxidant enzymes.

    PubMed

    Wang, Ping; Li, Chun Guang; Qi, Zhengtang; Cui, Di; Ding, Shuzhe

    2015-01-01

    Exercise induced skeletal muscle phenotype change involves a complex interplay between signaling pathways and downstream regulators. This study aims to investigate the effect of acute exercise on mitochondrial H2O2 production and its association with p(66Shc), FOXO3a, and antioxidant enzymes. Male ICR/CD-1 mice were subjected to an acute exercise. Muscle tissues (gastrocnemius and quadriceps femoris) were taken after exercise to measure mitochondrial H2O2 content, expression of p(66Shc) and FOXO3a, and the activity of antioxidant enzymes. The results showed that acute exercise significantly increased mitochondrial H2O2 content and expressions of p(66Shc) and FOXO3a in a time-dependent manner, with a linear correlation between the increase in H2O2 content and p(66Shc) or FOXO3a expression. The activity of mitochondrial catalase was slightly reduced in the 90 min exercise group, but it was significantly higher in groups with 120 and 150 min exercise compared to that of 90 min exercise group. The activity of SOD was not significantly affected. The results indicate that acute exercise increases mitochondrial H2O2 production in the skeletal muscle, which is associated with the upregulation of p(66Shc) and FOXO3a. The association of p(66Shc) and FOXO3a signaling with exercise induced H2O2 generation may play a role in regulating cellular oxidative stress during acute exercise. PMID:25874020

  20. Acute Exercise Induced Mitochondrial H2O2 Production in Mouse Skeletal Muscle: Association with p66Shc and FOXO3a Signaling and Antioxidant Enzymes

    PubMed Central

    Wang, Ping; Qi, Zhengtang; Cui, Di; Ding, Shuzhe

    2015-01-01

    Exercise induced skeletal muscle phenotype change involves a complex interplay between signaling pathways and downstream regulators. This study aims to investigate the effect of acute exercise on mitochondrial H2O2 production and its association with p66Shc, FOXO3a, and antioxidant enzymes. Male ICR/CD-1 mice were subjected to an acute exercise. Muscle tissues (gastrocnemius and quadriceps femoris) were taken after exercise to measure mitochondrial H2O2 content, expression of p66Shc and FOXO3a, and the activity of antioxidant enzymes. The results showed that acute exercise significantly increased mitochondrial H2O2 content and expressions of p66Shc and FOXO3a in a time-dependent manner, with a linear correlation between the increase in H2O2 content and p66Shc or FOXO3a expression. The activity of mitochondrial catalase was slightly reduced in the 90 min exercise group, but it was significantly higher in groups with 120 and 150 min exercise compared to that of 90 min exercise group. The activity of SOD was not significantly affected. The results indicate that acute exercise increases mitochondrial H2O2 production in the skeletal muscle, which is associated with the upregulation of p66Shc and FOXO3a. The association of p66Shc and FOXO3a signaling with exercise induced H2O2 generation may play a role in regulating cellular oxidative stress during acute exercise. PMID:25874020

  1. Muscle ultrastructural changes from exhaustive exercise performed after prolonged restricted activity and retraining in dogs

    NASA Technical Reports Server (NTRS)

    Nazar, K.; Greenleaf, J. E.; Philpott, D.; Pohoska, E.; Olszewska, K.; Kaciuba-Uscilko, H.

    1991-01-01

    The effect of exhaustive treadmill exercise on ultrastructural changes in the quadriceps femoris muscle was studied in 7 normal, healthy dogs, before and after restricted activity (RA), and following a subsequent 2 month treadmill exercise retraining period for the 5 mo group. Mean time to exhaustion in the 2 mo group decreased from 177 + or - 22 min before to 90 + or - 32 min after RA. Retraining increased tolerance to 219 + or - 73 min; 24 pct. above the before RA and 143 pct. above the after RA time. After RA exhaustion time in the 5 mo group was 25 and 45 min. Before RA, pre-exercise muscle structure was normal and post exercise there was only slight swelling of mitochondria. After RA, pre-exercise, numerous glycogen granules and lipid droplets appeared in the muscle fibers, mitochondria were smaller, and sarcoplasmic reticulum channels widened; post exercise these changes were accentuated and some areas were devoid of glycogen, and there was fiber degradation. After 5 mo RA pre-exercise there were more pronounced changes; mitochondria were very small and dense, there were many lipid droplets, myofibrils were often separated, and the fibers appeared edematous and degenerating; post exercise the sarcoplasmic reticulum was swollen, no glycogen was present, and there was marked swelling and deformation of mitochondria. After retraining, both pre-exercise and post exercise there was still evidence of fiber degeneration. Thus, susceptibility of active skeletal muscle structures and subcellular elements, e.g., mitochondria, to the action of damaging factors occurring during exhaustive exercise is enhanced considerably by prolonged disuse.

  2. Evaluation of an early exercise intervention after thoracotomy for non-small cell lung cancer (NSCLC), effects on quality of life, muscle strength and exercise tolerance: randomised controlled trial.

    PubMed

    Arbane, Gill; Tropman, David; Jackson, David; Garrod, Rachel

    2011-02-01

    Deterioration in exercise tolerance and impairment in quality of life (QoL) are common consequences of lobectomy. This study evaluates additional exercise and strength training after lung resection on QoL, exercise tolerance and muscle strength. Fifty-three (28 male) patients attending thoracotomy for lung cancer, mean age, range 64 (32-82) years; mean pack years (SD) 31.9 (26.8); BMI 25.6 (4.2); FEV1 2.0 (0.7) l were randomised to control (usual care) or intervention (twice daily training plus usual care). After discharge the intervention group received monthly home visits and weekly telephone calls, the control group received monthly telephone calls up to 12 weeks. Assessment pre-operatively, 5 day and 12 weeks post-operatively consisted of quadriceps strength using magnetic stimulation, 6 Minute Walking Distance (6MWD) and QoL-EORTC-QLQ-LC13. QoL was unchanged over 12 weeks; 6MWD showed significant deterioration at 5 days post-operatively compared with pre-operatively, mean difference (SD)-131.6 (101.8) m and -128.0 (90.7) m in active and control groups respectively (p=0.89 between groups) which returned to pre-operative levels by 12 weeks in both groups. Quadriceps strength over the 5 day in-patient period showed a decrease of -8.3 (11.3) kg in the control group compared to increase of 4.0 (21.2) kg in the intervention group (p=0.04 between groups). Strength training after thoracotomy successfully prevented the fall in quadriceps strength seen in controls, however, there was no effect on 6MWD or QoL. 6MWD returned to pre-operative levels by 12 weeks regardless of additional support offered. PMID:20541832

  3. An exercise programme for the management of lateral elbow tendinopathy

    PubMed Central

    Stasinopoulos, D; Stasinopoulou, K; Johnson, M

    2005-01-01

    Background: Home exercise programmes and exercise programmes carried out in a clinical setting are commonly advocated for the treatment of lateral elbow tendinopathy (LET), a very common lesion of the arm with a well-defined clinical presentation. The aim of this study is to describe the use and effects of strengthening and stretching exercise programmes in the treatment of LET. Eccentric exercises: Slow progressive eccentric exercises for LET should be performed with the elbow in extension, forearm in pronation, and wrist in extended position (as high as possible). However, it is unclear how the injured tendon, which is loaded eccentrically, returns to the starting position without experiencing concentric loading and how the "slowness" of eccentric exercises should be defined. Nor has the treatment regimen of the eccentric exercises of a supervised exercise programme been defined. Stretching exercises: Static stretching is defined as passively stretching a given muscle-tendon unit by slowly placing and maintaining it in a maximal position of stretch. We recommend the position should be held for 30–45 s, three times before and three times after eccentric exercises during each treatment session with a 30 s rest interval between each procedure. The treatment region of static stretching exercises when a supervised exercise programme is performed is unknown. Discussion: A well designed trial is needed to study the effectiveness of a supervised exercise programme for LET consisting of eccentric and static stretching exercises. The issues relating to the supervised exercise programme should be defined so that therapists can replicate the programme. PMID:16306504

  4. Exercise and Compulsive Behavior.

    ERIC Educational Resources Information Center

    Polivy, Janet; Clendenen, Vanessa

    Although reports on the positive effects of fitness and exercise predominate in the exercise literature, some researchers describe frequent exercise as compulsive or addictive behavior. This paper addresses these "negative addictions" of exercise. As early as 1970, researchers recognized the addictive qualities of exercise. Short-term studies on…

  5. Strengthening Concurrent Enrollment through NACEP Accreditation

    ERIC Educational Resources Information Center

    Scheffel, Kent; McLemore, Yvette; Lowe, Adam

    2015-01-01

    This chapter describes how implementing the National Alliance of Concurrent Enrollment Partnerships' 17 accreditation standards strengthens a concurrent enrollment program, enhances secondary-postsecondary relations, and benefits students, their families, and secondary and postsecondary institutions.

  6. 27 CFR 25.94 - Strengthening bonds.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... OF THE TREASURY ALCOHOL BEER Bonds and Consents of Surety § 25.94 Strengthening bonds. (a... sufficient, the principal may prepay the tax on beer as provided in subpart K of this part, or give...

  7. 27 CFR 25.94 - Strengthening bonds.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... OF THE TREASURY LIQUORS BEER Bonds and Consents of Surety § 25.94 Strengthening bonds. (a... sufficient, the principal may prepay the tax on beer as provided in subpart K of this part, or give...

  8. 27 CFR 25.94 - Strengthening bonds.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... OF THE TREASURY ALCOHOL BEER Bonds and Consents of Surety § 25.94 Strengthening bonds. (a... sufficient, the principal may prepay the tax on beer as provided in subpart K of this part, or give...

  9. Exercise and knee osteoarthritis: benefit or hazard?

    PubMed Central

    Bosomworth, Neil J.

    2009-01-01

    ABSTRACT OBJECTIVE To determine whether physical exercise constitutes a benefit or a risk in the development and progression of knee osteoarthritis. QUALITY OF EVIDENCE MEDLINE, EMBASE, DARE, ACP Journal Club, and Cochrane databases were searched from registry inception to January 2009 using MeSH headings or text words, including osteoarthritis, arthritis and knee and exercise, physical training, and run. Reference lists from retrieved articles, citation listings when available, and related articles suggested in PubMed were also evaluated. For individuals without osteoarthritis, strong level II evidence was found (limited by problems with blinding and randomization); for those with pre-existing knee osteoarthritis, robust level I evidence was available. MAIN MESSAGE Knee osteoarthritis is a major contributor to disability in seniors, and patients have expressed concern that continued exercise might lead to knee symptoms in later years. Studies done on subjects self-selected for exercise and followed for substantial periods of time show no evidence of accelerated development of osteoarthritis, provided injury is avoided. Further, there is good evidence for reduced pain and disability with exercise in this cohort compared with controls. Patients with established osteoarthritis are shown to derive uniform benefit to physical functioning, with reduction of pain and disability, using aerobic, muscle strengthening, aquatic, or physiotherapy-based exercise modalities. CONCLUSION Provided trauma is avoided, moderate exercise does not lead to acceleration of knee osteoarthritis, whether or not there is evidence of pre-existing disease. In either case there appears to be improved physical functioning and reduction of pain and disability in those who exercise. It is likely that exercise interventions are underused in the management of established knee osteoarthritis symptoms. PMID:19752252

  10. Reconstruction of medial patellofemoral ligament using quadriceps tendon combined with reconstruction of medial patellotibial ligament using patellar tendon: initial experience☆

    PubMed Central

    Hinckel, Betina Bremer; Gobbi, Riccardo Gomes; Bonadio, Marcelo Batista; Demange, Marco Kawamura; Pécora, José Ricardo; Camanho, Gilberto Luis

    2016-01-01

    Objective To describe a surgical technique for anatomical reconstruction of the medial patellofemoral ligament using the quadriceps tendon, combined with reconstruction of the medial patellotibial ligament using the patellar tendon; and to present the initial results from a case series. Method The proposed technique was used on a series of cases of patients with diagnoses of patellofemoral instability and indications for surgical treatment, who were attended by the Knee Group of HC-IOT, University of São Paulo. The following were evaluated before and after the operation: range of motion (ROM), apprehension test, lateral translation test, patellar inclination test, inverted J sign, subluxation upon extension, pain from compression of the patella and pain from contraction of the quadriceps. After the operation, the patients were asked whether any new episode of dislocation had occurred, what their degree of satisfaction with the surgery was (on a scale from 0 to 10) and whether they would be prepared to go through this operation again. Results Seven knees were operated, in seven patients, with a mean follow-up of 5.46 months (±2.07). Four patients who presented apprehension before the operation did not show this after the operation. The lateral translation test became normal for all the patients, while the patellar inclination test remained positive for two patients. The patients with an inverted J sign continued to be positive for this sign. Five patients were positive for subluxation upon extension before the operation, but all patients were negative for this after the operation. None of the patients presented any new episode of dislocation of the patella. All of them stated that they were satisfied: five gave a satisfaction score of 9 and two, a score of 10. All of them said that they would undergo the operation again. Only one patient presented a postoperative complication: dehiscence of the wound. Conclusion Reconstruction of the medial patellofemoral ligament using the quadriceps tendon, combined with reconstruction of the medial patellotibial ligament using the patellar tendon, was technically safe and presented good objective and subjective clinical results in this case series with a short follow-up. PMID:26962504

  11. No effect of glycogen level on glycogen metabolism during high intensity exercise.

    PubMed

    Vandenberghe, K; Hespel, P; Vanden Eynde, B; Lysens, R; Richter, E A

    1995-09-01

    This study examined the effect of glycogen supercompensation on glycogen breakdown, muscle and blood lactate accumulation, blood-pH, and performance during short-term high-intensity exercise. Young healthy volunteers performed two supramaximal (125% of VO2max) exercise tests on a bicycle ergometer, either for 1 min 45 s (protocol 1; N = 18) or to exhaustion (protocol 2; N = 14). The exercise tests were preceded by either 5 d on a controlled normal (N) diet, or by 2 d of glycogen-depleting exercise accompanied by the normal diet followed by 3 d on a carbohydrate-rich (CHR) diet. In protocol 1, preexercise muscle glycogen concentrations were 364 +/- 23 and 568 +/- 35 mumol.g-1 d.w. in the N and CHR condition, respectively (P < 0.05). During the exertion, glycogen concentration in the M. quadriceps decreased to the same extent in both groups. Accordingly, the exercise-induced increases in muscle and blood-lactate, and the fall in blood-pH were similar during N and CHR. In protocol 2, time to exhaustion was identical for N and CHR. It is concluded that during short-term intense exercise during which muscle glycogen availability exceeds glycogen demand, rate of glycogen breakdown, lactate accumulation, and performance are regulated irrespective of the preexercise muscle glycogen level. PMID:8531626

  12. Muscle mitochondrial density after exhaustive exercise in dogs - Prolonged restricted activity and retraining

    NASA Technical Reports Server (NTRS)

    Nazar, K.; Greenleaf, J. E.; Philpott, D.; Pohoska, E.; Olszewska, K.; Kaciuba-Uscilko, H.

    1993-01-01

    The effect of exhaustive treadmill exercise on mitochondrial density (MD) and ultrastructural changes in quadriceps femoris muscle was studied in 7 normal, healthy, male mongrel dogs before and after restricted activity (RA) and following a subsequent 2-month exercise retraining period. Mean time to exhaustion in the 2-month group decreased from 177 +/- 11 min before to 90 +/- 16 min after RA; retraining increased tolerance to 219 +/- 36 min above the pre-RA and 143 percent above the post-RA time. Post-RA exhaustion time in the 5-months group was 25 and 45 min. Muscle samples taken after RA showed abnormalities indicative of degeneration, which were reversed by retraining. Resting MD decreased from a control level of 27.8 percent to 14.7 percent and 16.3 percent, and was restored to 27.1 percent after retraining. Exhaustive exercise caused an increase in MD under control conditions and after RA, but not following retraining. Disruption of mitochondria after exercise was evident after 5-month confinement. Factors causing mitochondrial changes and eventually their disruption during exercise after restricted activity are not related as much to the state of fatigue as to the pre-exercise quality of the muscle modified by disease or training.

  13. Rotator cuff exercises

    MedlinePLUS

    Shoulder exercises ... A key part in your recovery is doing exercises to make the muscles and tendons in your ... for everyday tasks or sports activities Before doing exercises at home, ask your doctor or physical therapist ...

  14. Exercise and Physical Activity

    MedlinePLUS

    ... exercise videos/DVDs made for older people. • Add music to the exercises if it helps the person with Alzheimer’s disease. Dance to the music if possible. • Break exercises into simple, easy-to- ...

  15. Exercise-Induced Urticaria

    MedlinePLUS

    MENU Return to Web version Exercise-induced Urticaria Overview What is exercise-induced urticaria? Exercise-induced urticaria is a condition that causes hives and other allergic symptoms. It can occur during ...

  16. Exercise and Fitness

    MedlinePLUS

    ... strength training and some cardiovascular exercise is weight bearing. This means that, during exercise, your body is ... women. Water aerobics, however, is not a weight-bearing exercise and will not help prevent osteoporosis. Glossary ...

  17. Muscle fatigue during high-intensity exercise in children.

    PubMed

    Ratel, Sébastien; Duché, Pascale; Williams, Craig A

    2006-01-01

    Children are able to resist fatigue better than adults during one or several repeated high-intensity exercise bouts. This finding has been reported by measuring mechanical force or power output profiles during sustained isometric maximal contractions or repeated bouts of high-intensity dynamic exercises. The ability of children to better maintain performance during repeated high-intensity exercise bouts could be related to their lower level of fatigue during exercise and/or faster recovery following exercise. This may be explained by muscle characteristics of children, which are quantitatively and qualitatively different to those of adults. Children have less muscle mass than adults and hence, generate lower absolute power during high-intensity exercise. Some researchers also showed that children were equipped better for oxidative than glycolytic pathways during exercise, which would lead to a lower accumulation of muscle by-products. Furthermore, some reports indicated that the lower ability of children to activate their type II muscle fibres would also explain their greater resistance to fatigue during sustained maximal contractions. The lower accumulation of muscle by-products observed in children may be suggestive of a reduced metabolic signal, which induces lower ratings of perceived exertion. Factors such as faster phosphocreatine resynthesis, greater oxidative capacity, better acid-base regulation, faster readjustment of initial cardiorespiratory parameters and higher removal of metabolic by-products in children could also explain their faster recovery following high-intensity exercise.From a clinical point of view, muscle fatigue profiles are different between healthy children and children with muscle and metabolic diseases. Studies of dystrophic muscles in children indicated contradictory findings of changes in contractile properties and the muscle fatigability. Some have found that the muscle of boys with Duchenne muscular dystrophy (DMD) fatigued less than that of healthy boys, but others have reported that the fatigue in DMD and in normal muscle was the same. Children with glycogenosis type V and VII and dermatomyositis, and obese children tolerate exercise weakly and show an early fatigue. Studies that have investigated the fatigability in children with cerebral palsy have indicated that the femoris quadriceps was less fatigable than that of a control group but the fatigability of the triceps surae was the same between the two groups. Further studies are required to elucidate the mechanisms explaining the origins of muscle fatigue in healthy and diseased children. The use of non-invasive measurement tools such as magnetic resonance imaging and magnetic resonance spectroscopy in paediatric exercise science will give researchers more insight in the future. PMID:17123327

  18. Effect of exercise-induced fatigue on postural control of the knee.

    PubMed

    Hassanlouei, H; Arendt-Nielsen, L; Kersting, U G; Falla, D

    2012-06-01

    Muscle fatigue is associated with reduced power output and work capacity of the skeletal muscle. Fatigue-induced impairments in muscle function are believed to be a potential cause of increased injury rates during the latter stages of athletic competition and often occur during unexpected perturbations. However the effect of fatigue on functionally relevant, full body destabilizing perturbations has not been investigated. This study examines the effect of muscle fatigue on the activation of the quadriceps and hamstrings to fast, full body perturbations evoked by a moveable platform. Surface electromyographic (EMG) signals were recorded from the knee extensor (vastus medialis, rectus femoris, and vastus lateralis) and flexor muscles (biceps femoris and semitendinosus) of the right leg in nine healthy men during full body perturbations performed at baseline and immediately following high intensity exercise performed on a bicycle ergometer. In each condition, participants stood on a moveable platform during which 16 randomized postural perturbations (eight repetitions of two perturbation types: 8 cm forward slides, 8 cm backward slides) with varying inter-perturbation time intervals were performed over a period of 2-3 min. Maximal voluntary knee extension force was measured before and after the high intensity exercise protocol to confirm the presence of fatigue. Immediately after exercise, the maximal force decreased by 63% and 66% for knee extensors and flexors, respectively (P<0.0001). During the post-exercise postural perturbations, the EMG average rectified value (ARV) was significantly lower than the baseline condition for both the knee extensors (average across all muscles; baseline: 19.7±25.4μV, post exercise: 16.2±19.4 μV) and flexors (baseline: 24.3±20.9 μV, post exercise: 13.8±11.0 μV) (both P<0.05). Moreover the EMG onset was significantly delayed for both the knee extensors (baseline: 132.7±32.9 ms, post exercise: 170.8±22.9 ms) and flexors (baseline: 139.1±38.8 ms, post exercise: 179.3±50.9 ms) (both P<0.05). A significant correlation (R(2)=0.53; P<0.05) was identified between the percent reduction of knee extension MVC and the percent change in onset time of the knee extensors post exercise. This study shows that muscle fatigue induces a reduction and delay in the activation of both the quadriceps and hamstring muscles in response to rapid destabilizing perturbations potentially reducing the stability around the knee. PMID:22366254

  19. Downregulation of the serum response factor/miR-1 axis in the quadriceps of patients with COPD

    PubMed Central

    Lewis, Amy; Riddoch-Contreras, Joanna; Natanek, Samantha A; Donaldson, Anna; Man, William D-C; Moxham, John; Hopkinson, Nicholas S; Polkey, Michael I

    2011-01-01

    Rationale Muscle atrophy confers a poor prognosis in patients with chronic obstructive pulmonary disease (COPD), yet the molecular pathways responsible are poorly characterised. Muscle-specific microRNAs and serum response factor (SRF) are important regulators of muscle phenotype that contribute to a feedback system to regulate muscle gene expression. The role of these factors in the skeletal muscle dysfunction that accompanies COPD is unknown. Methods 31 patients with COPD and 14 healthy age-matched controls underwent lung and quadriceps function assessments, measurement of daily activity and a percutaneous quadriceps muscle biopsy. The expression of muscle-specific microRNAs, myosin heavy chains and components of the serum response factor signalling pathway were determined by qPCR. Results A reduction in expression of miR-1 (2.5-fold, p=0.01) and the myocardin-related transcription factors (MRTFs) A and B was observed in patients compared with controls (MRTF-A mRNA: twofold, p=0.028; MRTF-B mRNA: fourfold, p=0.011). miR-1 expression was associated with smoking history, lung function, fat-free mass index, 6 min walk distance and percentage of type 1 fibres. miR-133 and miR-206 were negatively correlated with daily physical activity. Insulin-like growth factor 1 mRNA was increased in the patients and miR-1 was negatively correlated with phosphorylation of the kinase Akt. Furthermore, the protein levels of histone deacetylase 4, another miR-1 target, were increased in the patients. Conclusions Downregulation of the activity of the MRTF-SRF axis and the expression of muscle-specific microRNAs, particularly miR-1, may contribute to COPD-associated skeletal muscle dysfunction. PMID:21998125

  20. Strength Training to Contraction Failure Increases Voluntary Activation of the Quadriceps Muscle Shortly After Total Knee Arthroplasty

    PubMed Central

    Mikkelsen, Elin Karin; Jakobsen, Thomas Linding; Holsgaard-Larsen, Anders; Andersen, Lars Louis; Bandholm, Thomas

    2016-01-01

    ABSTRACT Objective The objective of this study was to investigate voluntary activation of the quadriceps muscle during one set of knee extensions performed until contraction failure in patients shortly after total knee arthroplasty. Design This was a cross-sectional study of 24 patients with total knee arthroplasty. One set of knee extensions was performed until contraction failure, using a predetermined 10 repetition maximum loading. In the operated leg, electromyographic (EMG) activity of the lateral and medial vastus, semitendinosus, and biceps femoris muscles was recorded during the set. Muscle activity (%EMGmax) and median power frequency of the EMG power spectrum were calculated for each repetition decile (10%–100% contraction failure). Results Muscle activity increased significantly over contractions from a mean of 90.0 and 93.6 %EMGmax (lateral vastus and medial vastus, respectively) at 10% contraction failure to 99.3 and 105.5 %EMGmax at 100% contraction failure (P = 0.009 and 0.004). Median power frequency decreased significantly over contractions from a mean of 66.8 and 64.2 Hz (lateral vastus and medial vastus, respectively) at 10% contraction failure to 59.9 and 60.1 Hz at 100% contraction failure (P = 0.0006 and 0.0187). Conclusion In patients shortly after total knee arthroplasty, 10 repetition maximum–loaded knee extensions performed in one set until contraction failure increases voluntary activation of the quadriceps muscle during the set. Clinical Trials Gov-identifier: NCT01713140 to the abstract to increase trial transparency. PMID:26339729

  1. Resistance Versus Aerobic Exercise

    PubMed Central

    Yardley, Jane E.; Kenny, Glen P.; Perkins, Bruce A.; Riddell, Michael C.; Balaa, Nadia; Malcolm, Janine; Boulay, Pierre; Khandwala, Farah; Sigal, Ronald J.

    2013-01-01

    OBJECTIVE In type 1 diabetes, small studies have found that resistance exercise (weight lifting) reduces HbA1c. In the current study, we examined the acute impacts of resistance exercise on glycemia during exercise and in the subsequent 24 h compared with aerobic exercise and no exercise. RESEARCH DESIGN AND METHODS Twelve physically active individuals with type 1 diabetes (HbA1c 7.1 ± 1.0%) performed 45 min of resistance exercise (three sets of seven exercises at eight repetitions maximum), 45 min of aerobic exercise (running at 60% of Vo2max), or no exercise on separate days. Plasma glucose was measured during and for 60 min after exercise. Interstitial glucose was measured by continuous glucose monitoring 24 h before, during, and 24 h after exercise. RESULTS Treatment-by-time interactions (P < 0.001) were found for changes in plasma glucose during and after exercise. Plasma glucose decreased from 8.4 ± 2.7 to 6.8 ± 2.3 mmol/L (P = 0.008) during resistance exercise and from 9.2 ± 3.4 to 5.8 ± 2.0 mmol/L (P = 0.001) during aerobic exercise. No significant changes were seen during the no-exercise control session. During recovery, glucose levels did not change significantly after resistance exercise but increased by 2.2 ± 0.6 mmol/L (P = 0.023) after aerobic exercise. Mean interstitial glucose from 4.5 to 6.0 h postexercise was significantly lower after resistance exercise versus aerobic exercise. CONCLUSIONS Resistance exercise causes less initial decline in blood glucose during the activity but is associated with more prolonged reductions in postexercise glycemia than aerobic exercise. This might account for HbA1c reductions found in studies of resistance exercise but not aerobic exercise in type 1 diabetes. PMID:23172972

  2. A preliminary, randomized trial of aerobic exercise for alcohol dependence

    PubMed Central

    Brown, Richard A.; Abrantes, Ana M.; Minami, Haruka; Read, Jennifer P.; Marcus, Bess H.; Jakicic, John M.; Strong, David R.; Dubreuil, Mary Ella; Gordon, Alan A.; Ramsey, Susan E.; Kahler, Christopher W.; Stuart, Gregory L.

    2015-01-01

    Interventions targeting physical activity may be valuable as an adjunct to alcohol treatment, but have been relative untested. In the current study, alcohol dependent, physically sedentary patients were randomized to: a 12-week moderate-intensity, group aerobic exercise intervention (AE; n = 25) or a brief advice to exercise intervention (BA-E; n=23). Results showed that individuals in AE reported significantly fewer drinking and heavy drinking days, relative to BA-E during treatment. Furthermore adherence to AE strengthened the beneficial effect of intervention on alcohol use outcomes. While high levels of moderate-intensity exercise appeared to facilitate alcohol recovery regardless of intervention arm, attending the group-based AE intervention seemed to further enhance the positive effects of exercise on alcohol use. Study findings indicate that a moderate intensity, group aerobic exercise intervention is an efficacious adjunct to alcohol treatment. Improving adherence to the intervention may enhance its beneficial effects on alcohol use. PMID:24666811

  3. Bone mineral density, muscle strength, and recreational exercise in men

    NASA Technical Reports Server (NTRS)

    Snow-Harter, C.; Whalen, R.; Myburgh, K.; Arnaud, S.; Marcus, R.

    1992-01-01

    Muscle strength has been shown to predict bone mineral density (BMD) in women. We examined this relationship in 50 healthy men who ranged in age from 28 to 51 years (average 38.3 years). BMD of the lumbar spine, proximal femur, whole body, and tibia were measured by dual-energy x-ray absorptiometry (Hologic QDR 1000W). Dynamic strength using one repetition maximum was assessed for the biceps, quadriceps, and back extensors and for the hip abductors, adductors, and flexors. Isometric grip strength was measured by dynamometry. Daily walking mileage was assessed by 9 week stepmeter records and kinematic analysis of video filming. Subjects were designated as exercisers and nonexercisers. Exercisers participated in recreational exercise at least two times each week. The results demonstrated that BMD at all sites correlated with back and biceps strength (p < 0.01 to p = 0.0001). Body weight correlated with tibia and whole-body BMD (p < 0.001); age negatively correlated with Ward's triangle BMD (p < 0.01). In stepwise multiple regressions, back strength was the only independent predictor of spine and femoral neck density (R2 = 0.27). Further, back strength was the most robust predictor of BMD at the trochanter, Ward's triangle, whole body, and tibia, although biceps strength, age, body weight, and leg strength contributed significantly to BMD at these skeletal sites, accounting for 35-52% of the variance in BMD. Exercisers and nonexercisers were similar for walking (3.97 versus 3.94 miles/day), age (37.8 versus 38.5) years, and weight (80.0 versus 77.7 kg). However, BMD and muscle strength were significantly greater in exercises than in nonexercisers.(ABSTRACT TRUNCATED AT 250 WORDS).

  4. Effect of resistance training on muscle use during exercise

    NASA Technical Reports Server (NTRS)

    Ploutz, Lori L.; Tesch, Per A.; Biro, Ronald L.; Dudley, Gary A.

    1994-01-01

    This study examined the effect of resistance training on exercise-induced contrast shift in magnetic resonance (MR) images. It was hypothesized that a given load could be lifted after training with less muscle showing contrast shift, thereby suggesting less muscle was used to perform the exercise. Nine males trained the left quadriceps femoris (QF) muscle 2 days/wk for 9 wk using 3-6 sets of 12 knee extensions each day. The right QF served as a control. Exercise-induced contrast shifts in MR images evoked by each of three bouts of exercise (5 sets of 10 knee extensions with a load equal to 50, 75, and 100% of the maximum pretraining load that could be lifted for 5 sets of 10 repetitions) were quantified pre- and posttraining. MR image contrast shift was quantified by determining QF cross-sectional area (CSA) showing increased spin-spin relaxation time. One repetition maximum increased 14% in the left trained QF and 7% in the right untrained QF. Left QF CSA increased 5%, with no change in right QSF CSA. Left QF CSA showing contrast shift was less after each bout of the exercise test posttraining. This was also true, to a lesser extent, for the right QF at the higher two loads. The results suggest that short-term resistance training reduces MR image contrast shift evoked by a given effort, thereby reflecting the use of less muscle to lift the load. Because this response was evident in both trained and contralateral untrained muscle, neural factors are suggested to be responsible. The consequence of this adaptation could be to increase 'stress' per unit area of active muscle during the course of training and thereby evoke hypertrophy.

  5. Boron strengthening in FeAl

    SciTech Connect

    Baker, I.; Li, X.; Xiao, H.; Klein, O.; Nelson, C.; Carleton, R.L.; George, E.P.

    1998-11-01

    The effect of boron on the strength of B2-structured FeAl is considered as a function of composition, grain size and temperature. Boron does not affect the concentrations of antisite atoms or vacancies present, with the former increasing and the latter decreasing with increasing deviation from the stoichiometric composition. When vacancies are absent, the strength increase per at. % B per unit lattice strain, {Delta}{sigma}/({Delta}c x {epsilon}) increases with increasing aluminum concentration, but when vacancies are present (>45 at. % Al), {Delta}{sigma}/({Delta}c x {epsilon}) decreases again. Boron increases grain size strengthening in FeAl. B strengthening is roughly independent of temperature up to the yield strength peak but above the point, when diffusion-assisted deformation occurs, boron strengthening increases dramatically.

  6. Exercise Is Medicine.

    ERIC Educational Resources Information Center

    Elrick, Harold

    1996-01-01

    Suggests that exercise should be the first-line therapy for preventing and treating many common diseases; however, physicians need more training in how best to use exercise therapy. The paper explains the power of exercise and discusses how to motivate individuals to start safe, enjoyable, and life-saving exercise routines. (SM)

  7. Postpartum Exercise and Lactation.

    PubMed

    Bane, Susan M

    2015-12-01

    Many women who are breastfeeding also want to participate in exercise, but have concerns about the safety of their newborn. The following chapter reviews issues related to postpartum exercise and lactation. The goals of the chapter are to help clinicians understand the benefits of exercise, examine the impact of postpartum exercise on breastfeeding, and provide practical recommendations for exercise during the postpartum period in women who are breastfeeding. PMID:26398298

  8. The effects of electrical stimulation and exercise therapy in patients with limb girdle muscular dystrophy

    PubMed Central

    Kılınç, Muhammed; Yıldırım, Sibel A.; Tan, Ersin

    2015-01-01

    Objective: To evaluate and compare the effects of exercise therapy and electrical stimulation on muscle strength and functional activities in patients with limb-girdle muscular dystrophy (LGMD). Methods: This controlled clinical trial included 24 subjects who were diagnosed with LGMD by the Neurology Department of the Hacettepe University Hospital, Ankara, Turkey and were referred to the Physical Therapy Department between May 2013 and December 2014. Subjects were enrolled into an electrical stimulation (11 patients) group, or an exercise therapy (13 patients) group. Results: The mean age of patients was 31.62 years in the electrical stimulation group, and 30.14 years in the exercise therapy group. The most important results in this controlled clinical study were that the muscle strength in both groups was significantly decreased and post-treatment evaluation results indicated that muscle strength of the Deltoideus was higher in the electrical stimulation group, and the difference between the groups was maintained in the follow-up period (p<0.05). However, the muscle strength of quadriceps was similar in both groups, according to the post-treatment and follow-up evaluation results (p>0.05). Additionally, the electrical stimulation group presented more obvious overall improvements than the exercise therapy group according to muscle strength, endurance, and timed performance tests. Conclusions: Since no definitive treatments currently exist for patients with LGMD, these results provide important information on the role of exercise therapy and electrical stimulation for clinicians working in rehabilitation. PMID:26166595

  9. Increased hypoxic ventilatory sensitivity during exercise in man: are neural afferents necessary?

    PubMed

    Pandit, J J; Bergstrom, E; Frankel, H L; Robbins, P A

    1994-05-15

    1. The acute ventilatory response to 3 min periods of hypoxia (AHR) was examined in nine patients with clinically complete spinal cord transection (T4-T7) during (a) rest and (b) electrically induced leg exercise (EEL). 2. EEL was produced by surface electrode stimulation of the quadriceps muscles so as to cause the legs to extend at the knee against gravity. End-tidal PCO2 was held constant 1-2 mmHg above resting values throughout both protocols. 3. On exercise, the average increase in metabolic CO2 production (VCO2 +/- S.E.M.) was 41 +/- 5 ml min-1. Venous lactate levels did not rise with exercise. 4. Baseline euoxic ventilation did not increase significantly with EEL, but there was a consistent and highly significant increase in the ventilatory response to hypoxia during EEL (mean delta AHR +/- S.E.M. of 1.6 +/- 0.21 min-1). 5. We conclude that an increase in hypoxic sensitivity during exercise can occur in the absence of volitional control of exercise and in the absence of afferent neural input from the limbs. PMID:8071884

  10. Increased hypoxic ventilatory sensitivity during exercise in man: are neural afferents necessary?

    PubMed Central

    Pandit, J J; Bergstrom, E; Frankel, H L; Robbins, P A

    1994-01-01

    1. The acute ventilatory response to 3 min periods of hypoxia (AHR) was examined in nine patients with clinically complete spinal cord transection (T4-T7) during (a) rest and (b) electrically induced leg exercise (EEL). 2. EEL was produced by surface electrode stimulation of the quadriceps muscles so as to cause the legs to extend at the knee against gravity. End-tidal PCO2 was held constant 1-2 mmHg above resting values throughout both protocols. 3. On exercise, the average increase in metabolic CO2 production (VCO2 +/- S.E.M.) was 41 +/- 5 ml min-1. Venous lactate levels did not rise with exercise. 4. Baseline euoxic ventilation did not increase significantly with EEL, but there was a consistent and highly significant increase in the ventilatory response to hypoxia during EEL (mean delta AHR +/- S.E.M. of 1.6 +/- 0.21 min-1). 5. We conclude that an increase in hypoxic sensitivity during exercise can occur in the absence of volitional control of exercise and in the absence of afferent neural input from the limbs. PMID:8071884

  11. Physiological benefits of exercise in artificial gravity: A broadband countermeasure to space flight related deconditioning

    NASA Astrophysics Data System (ADS)

    Edmonds, Jessica L.; Jarchow, Thomas; Young, Laurence R.

    2008-07-01

    Current countermeasures to space flight related physiological deconditioning have not been sufficiently effective. We believe that a comprehensive countermeasure is the combination of intermittent centrifugation (artificial gravity) and exercise. We aim to test the long-term effectiveness of this combination in terms of fitness benefits. As a first-order determination of effectiveness, subjects participated in an eight-week exercise program. Three times per week, they exercised using a stair-stepper on a short-radius (2 m) centrifuge spinning at 30 RPM, maintaining a target heart rate that was systematically increased over the exercise period. During the sessions, foot forces and stepping cadence, heart rate, and perceived exertion were measured. Before and after the eight-week exercise program, measurements included: body fat percentage, bone mineral content, quadriceps extension strength, push-ups endurance, stepping cadence for a given heart rate, and maximum stepping endurance. We find that stair-stepping on a centrifuge is safe and comfortable. Preliminary fitness results indicate that stair-stepping on a centrifuge may be effective in improving aerobic fitness, body composition, and strength. These results indicate that such a combination may also be effective as a countermeasure to space flight deconditioning.

  12. Exercise with and without gravitational gradient: evaluation with the new random access mass spectrometer (RAMS).

    PubMed

    Hughson, R L; Shoemaker, J K; Tschakovsky, M E; Corsale, D; Dietrich, B H

    1995-01-01

    Gravity adds about 40-50 mmHg perfusion pressure to the arterial supply of the quadriceps muscles in the upright posture. This could have important implications in supply of blood flow during exercise. Recently, we have shown that when subjects exercise in the supine posture the rate of increase in VO2 is considerably slower then when cycling exercise takes place in the upright posture. The most probable explanation for this slower adaptation was the altered perfusion gradient. Indeed, when the perfusion gradient from heart to legs was restored by placing the lower part of the body of supine subjects in a negative pressure chamber, the rate of increase in VO2 returned to upright values. The hypothesis advanced from these studies was that skeletal muscle blood flow was reduced at the onset of supine exercise. Exercise in the microgravity environment of space should be similar to that in the supine posture. The only experiments conducted in space to this date that have addressed the question of cardiorespiratory adaptation to changing work rates were performed on the German D2 mission using the methodology proposed by Stegemann and colleagues. To conduct these experiments, it is necessary to utilize sensitive breath-by-breath technology. Recently, NASA and the Russian space programs have commissioned a new mass spectrometer based system as part of the GASMAP project. It was the purpose of this study to evaluate the new mass spectrometer under conditions in which the gravitational effects on the cardiorespiratory response were being challenged. PMID:11538934

  13. Physiological Correlates of Endurance Time Variability during Constant-Workrate Cycling Exercise in Patients with COPD

    PubMed Central

    Vivodtzev, Isabelle; Gagnon, Philippe; Pepin, Vronique; Saey, Didier; Laviolette, Louis; Brouillard, Cynthia; Maltais, Franois

    2011-01-01

    Rationale The endurance time (Tend) during constant-workrate cycling exercise (CET) is highly variable in COPD. We investigated pulmonary and physiological variables that may contribute to these variations in Tend. Methods Ninety-two patients with COPD completed a CET performed at 80% of peak workrate capacity (Wpeak). Patients were divided into tertiles of Tend [Group 1: <4 min; Group 2: 46 min; Group 3: >6 min]. Disease severity (FEV1), aerobic fitness (Wpeak, peak oxygen consumption [peak], ventilatory threshold [VT]), quadriceps strength (MVC), symptom scores at the end of CET and exercise intensity during CET (heart rate at the end of CET to heart rate at peak incremental exercise ratio [HRCET/HRpeak]) were analyzed as potential variables influencing Tend. Results Wpeak, peak, VT, MVC, leg fatigue at end of CET, and HRCET/HRpeak were lower in group 1 than in group 2 or 3 (p?0.05). VT and leg fatigue at end of CET independently predicted Tend in multiple regression analysis (r?=?0.50, p?=?0.001). Conclusion Tend was independently related to the aerobic fitness and to tolerance to leg fatigue at the end of exercise. A large fraction of the variability in Tend was not explained by the physiological parameters assessed in the present study. Individualization of exercise intensity during CET should help in reducing variations in Tend among patients with COPD. PMID:21386991

  14. Transcranial magnetic stimulation intensity affects exercise-induced changes in corticomotoneuronal excitability and inhibition and voluntary activation.

    PubMed

    Bachasson, D; Temesi, J; Gruet, M; Yokoyama, K; Rupp, T; Millet, G Y; Verges, Samuel

    2016-02-01

    Transcranial magnetic stimulation (TMS) of the motor cortex during voluntary contractions elicits electrophysiological and mechanical responses in the target muscle. The effect of different TMS intensities on exercise-induced changes in TMS-elicited variables is unknown, impairing data interpretation. This study aimed to investigate TMS intensity effects on maximal voluntary activation (VATMS), motor-evoked potentials (MEPs), and silent periods (SPs) in the quadriceps muscles before, during, and after exhaustive isometric exercise. Eleven subjects performed sets of ten 5-s submaximal isometric quadriceps contractions at 40% of maximal voluntary contraction (MVC) strength until task failure. Three different TMS intensities (I100, I75, I50) eliciting MEPs of 53±6%, 38±5% and 25±3% of maximal compound action potential (Mmax) at 20% MVC were used. MEPs and SPs were assessed at both absolute (40% baseline MVC) and relative (50%, 75%, and 100% MVC) force levels. VATMS was assessed with I100 and I75. When measured at absolute force level, MEP/Mmax increased during exercise at I50, decreased at I100 and remained unchanged at I75. No TMS intensity effect was observed at relative force levels. At both absolute and relative force levels, SPs increased at I100 and remained stable at I75 and I50. VATMS assessed at I75 tended to be lower than at I100. TMS intensity affects exercise-induced changes in MEP/Mmax (only when measured at absolute force level), SPs, and VATMS. These results indicate a single TMS intensity assessing maximal voluntary activation and exercise-induced changes in corticomotoneuronal excitability/inhibition may be inappropriate. PMID:26642805

  15. Reduction of O2 slow component by priming exercise: novel mechanistic insights from time-resolved near-infrared spectroscopy

    PubMed Central

    Fukuoka, Yoshiyuki; Poole, David C; Barstow, Thomas J; Kondo, Narihiko; Nishiwaki, Masato; Okushima, Dai; Koga, Shunsaku

    2015-01-01

    Novel time-resolved near-infrared spectroscopy (TR-NIRS), with adipose tissue thickness correction, was used to test the hypotheses that heavy priming exercise reduces the V?O2 slow component (V?O2SC) (1) by elevating microvascular [Hb] volume at multiple sites within the quadriceps femoris (2) rather than reducing the heterogeneity of muscle deoxygenation kinetics. Twelve subjects completed two 6-min bouts of heavy work rate exercise, separated by 6min of unloaded cycling. Priming exercise induced faster overall V?O2 kinetics consequent to a substantial reduction in the V?O2SC (0.270.12 vs. 0.110.09Lmin?1, P<0.05) with an unchanged primary V?O2 time constant. An increased baseline for the primed bout [total (Hb+Mb)] (197.521.6 vs. 210.722.5?molL?1, P<0.01), reflecting increased microvascular [Hb] volume, correlated significantly with the V?O2SC reduction. At multiple sites within the quadriceps femoris, priming exercise reduced the baseline and slowed the increase in [deoxy (Hb+Mb)]. Changes in the intersite coefficient of variation in the time delay and time constant of [deoxy (Hb+Mb)] during the second bout were not correlated with the V?O2SC reduction. These results support a mechanistic link between priming exercise-induced increase in muscle [Hb] volume and the reduced V?O2SC that serves to speed overall V?O2 kinetics. However, reduction in the heterogeneity of muscle deoxygenation kinetics does not appear to be an obligatory feature of the priming response. PMID:26109190

  16. Strengthening Family Practices for Latino Families

    ERIC Educational Resources Information Center

    Chartier, Karen G.; Negroni, Lirio K.; Hesselbrock, Michie N.

    2010-01-01

    This study examined the effectiveness of a culturally adapted Strengthening Families Program (SFP) for Latinos to reduce risks for alcohol and drug use in children. Latino families, predominantly Puerto Rican, with a 9- to 12-year-old child and a parent(s) with a substance abuse problem participated in the study. Pre- and post-tests were conducted…

  17. Working Together for Children: Strengthening Transition Pathways

    ERIC Educational Resources Information Center

    Collie, Louise; Willis, Felicity; Paine, Crystal; Windsor, Corina

    2007-01-01

    The "Working Together for Children: Strengthening Transition Pathways" Team has identified that there is a gap between the Early Childhood settings and schools within the Dubbo area. Through meetings with early childhood professionals within Dubbo the authors have identified that the current landscape of care and education within their community…

  18. Using Peers and Technology to Strengthen Leadership.

    ERIC Educational Resources Information Center

    Lepard, David H.

    2002-01-01

    Describes a new, successful, leadership development program designed to target and strengthen key performance skills. The technology couples pedagogy and video and computer technology to build the Professional Enhancement Program currently used to improve the performance of prospective and practicing school leaders in 20 sites across 7 states.…

  19. Strengthening 4-H by Analyzing Enrollment Data

    ERIC Educational Resources Information Center

    Hamilton, Stephen F.; Northern, Angela; Neff, Robert

    2014-01-01

    The study reported here used data from the ACCESS 4-H Enrollment System to gain insight into strengthening New York State's 4-H programming. Member enrollment lists from 2009 to 2012 were analyzed using Microsoft Excel to determine trends and dropout rates. The descriptive data indicate declining 4-H enrollment in recent years and peak…

  20. 78 FR 38053 - Regulatory Systems Strengthening

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-25

    ... HUMAN SERVICES Food and Drug Administration Regulatory Systems Strengthening AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug Administration (FDA) is announcing the...-1, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 32, Silver Spring, MD 20993,...

  1. Working Together for Children: Strengthening Transition Pathways

    ERIC Educational Resources Information Center

    Collie, Louise; Willis, Felicity; Paine, Crystal; Windsor, Corina

    2007-01-01

    The "Working Together for Children: Strengthening Transition Pathways" Team has identified that there is a gap between the Early Childhood settings and schools within the Dubbo area. Through meetings with early childhood professionals within Dubbo the authors have identified that the current landscape of care and education within their community

  2. Strengthening 4-H by Analyzing Enrollment Data

    ERIC Educational Resources Information Center

    Hamilton, Stephen F.; Northern, Angela; Neff, Robert

    2014-01-01

    The study reported here used data from the ACCESS 4-H Enrollment System to gain insight into strengthening New York State's 4-H programming. Member enrollment lists from 2009 to 2012 were analyzed using Microsoft Excel to determine trends and dropout rates. The descriptive data indicate declining 4-H enrollment in recent years and peak

  3. Strengthening State Library Administrative Agency (Territorial Library).

    ERIC Educational Resources Information Center

    Nieves M. Flores Memorial Library, Agana, Guam.

    This document describes the Basic State Plan Amendments for the Library Services and Construction Act in Guam and the regulations promulgated thereunder. The major projects described under the plan are: Strengthening State Library Administrative Agency; Staff Development; Library Collections, Extention Services, Institutional Libraries; and…

  4. The "Drug Court Strengthening Families" Program.

    ERIC Educational Resources Information Center

    Logan, TK; Leukefeld, Carl; Minton, Lisa; Abrahmson, Joanie; Hughes, Rebecca

    2001-01-01

    Children of Drug Court clients are at high-risk for substance abuse and other risk factors. This paper summarizes the results of a program needs assessment, process evaluation, and outcome evaluation from the Kentucky Drug Court Strengthening Families Pilot Program. Results indicated overall positive changes for families in the program.

  5. Strengthening 4-H Program Communication through Technology

    ERIC Educational Resources Information Center

    Robideau, Kari; Santl, Karyn

    2011-01-01

    Advances in technology are transforming how youth and parents interact with programs. The Strengthening 4-H Communication through Technology project was implemented in eight county 4-H programs in Northwest Minnesota. This article outlines the intentional process used to effectively implement technology in program planning. The project includes:…

  6. An EMG comparative analysis of quadriceps during isoinertial strength training using nonlinear scaled wavelets.

    PubMed

    Napoli, Nicholas J; Mixco, Anthony R; Bohorquez, Jorge E; Signorile, Joseph F

    2015-04-01

    High-speed resistance training is used to increase power; however, momentum can reduce the effectiveness of high-speed (HS) training when using weight-stack (WS) machines. This study used a non-linear scaled wavelet analysis to assess differences between pneumatic (P) and WS during seven HS or controlled speed (CS) repetitions. Vastus medialis (VM) and lateralis (VL), and rectus femoris (RF) EMG data were collected during leg extension exercises performed by five regular weight-trainers (mean age ± SD, 23.2 ± 2.9 years). Data were analyzed using continuous wavelet analysis to assess temporal Intensity distribution across eight frequency bands. Significant differences occurred due to speed for all muscles (p<.0001). P produced higher Intensity than WS for all muscles during HS (p<.0001), and VM and RF during CS (p<.001). The CON phase produced higher Intensity than ECC for the vasti muscles during CS (p<.0003), and VM and RF during HS (p<.0001). Intensity increased across repetitions plateauing earlier for the vasti than RF during CS. Regardless of the machine, Intensity levels peaked between the 25-53 Hz and 46-82 Hz (2nd and 3rd wavelets) bands. The results indicate that when the objective is increasing power through isoinertial training, P machines at HS appear to be the most effective alternative. PMID:25553560

  7. Anterior cruciate ligament (ACL) reconstruction with quadriceps tendon autograft and press-fit fixation using an anteromedial portal technique

    PubMed Central

    2012-01-01

    Background This article describes an arthroscopic anterior cruciate ligament (ACL) reconstruction technique with a quadriceps tendon autograft using an anteromedial portal technique. Methods A 5 cm quadriceps tendon graft is harvested with an adjacent 2 cm bone block. The femoral tunnel is created through a low anteromedial portal in its anatomical position. The tibial tunnel is created with a hollow burr, thus acquiring a free cylindrical bone block. The graft is then passed through the tibial tunnel and the bone block, customized at its tip, is tapped into the femoral tunnel through the anteromedial portal to provide press-fit fixation. The graft is tensioned distally and sutures are tied over a bone bridge at the distal end of the tibial tunnel. From the cylindrical bone block harvested from the tibia the proximal end is customized and gently tapped next to the graft tissue into the tibial tunnel to assure press fitting of the graft in the tibial tunnel. The distal part of the tibial tunnel is filled up with the remaining bone. All patients were observed in a prospective fashion with subjective and objective evaluation after 6 weeks, 6 and 12 months. Results Thirty patients have been evaluated at a 12 months follow-up. The technique achieved in 96.7% normal or nearly normal results for the objective IKDC. The mean subjective IKDC score was 86.1 ± 15.8. In 96.7% the Tegner score was the same as before injury or decreased one category. A negative or 1+ Lachman test was achieved in all cases. Pivot-shift test was negative or (+) glide in 86.7%. The mean side-to-side difference elevated by instrumental laxity measurement was 1.6 ± 1.1 mm. Full ROM has been achieved in 92.3%. The mean single one-leg-hop index was 91.9 ± 8.0 at the follow-up. Conclusions Potential advantages include minimum bone loss specifically on the femoral side and graft fixation without implants. PMID:22925587

  8. Motor unit recruitment when neuromuscular electrical stimulation is applied over a nerve trunk compared with a muscle belly: quadriceps femoris.

    PubMed

    Bergquist, A J; Wiest, M J; Collins, D F

    2012-07-01

    Neuromuscular electrical stimulation (NMES) can be delivered over a nerve trunk or muscle belly and both can generate contractions through peripheral and central pathways. Generating contractions through peripheral pathways is associated with a nonphysiological motor unit recruitment order, which may limit the efficacy of NMES rehabilitation. Presently, we compared recruitment through peripheral and central pathways for contractions of the knee extensors evoked by NMES applied over the femoral nerve vs. the quadriceps muscle. NMES was delivered to evoke 10 and 20% of maximum voluntary isometric contraction torque 2-3 s into the NMES (time(1)) in two patterns: 1) constant frequency (15 Hz for 8 s); and 2) step frequency (15-100-15 Hz and 25-100-25 Hz for 3-2-3 s, respectively). Torque and electromyographic activity recorded from vastus lateralis and medialis were quantified at the beginning (time(1)) and end (time(2); 6-7 s into the NMES) of each pattern. M-waves (peripheral pathway), H-reflexes, and asynchronous activity (central pathways) during NMES were quantified. Torque did not differ regardless of NMES location, pattern, or time. For both muscles, M-waves were ∼7-10 times smaller and H-reflexes ∼8-9 times larger during NMES over the nerve compared with over the muscle. However, unlike muscles studied previously, neither torque nor activity through central pathways were augmented following 100 Hz NMES, nor was any asynchronous activity evoked during NMES at either location. The coefficient of variation was also quantified at time(2) to determine the consistency of each dependent measure between three consecutive contractions. Torque, M-waves, and H-reflexes were most variable during NMES over the nerve. In summary, NMES over the nerve produced contractions with the greatest recruitment through central pathways; however, considering some of the limitations of NMES over the femoral nerve, it may be considered a good complement to, as opposed to a replacement for, NMES over the quadriceps muscle for maintaining muscle quality and reducing contraction fatigue during NMES rehabilitation. PMID:22556395

  9. Recovery from cycling exercise: effects of carbohydrate and protein beverages.

    PubMed

    Goh, Qingnian; Boop, Christopher A; Luden, Nicholas D; Smith, Alexia G; Womack, Christopher J; Saunders, Michael J

    2012-07-01

    The effects of different carbohydrate-protein (CHO + Pro) beverages were compared during recovery from cycling exercise. Twelve male cyclists (VO(2peak): 65 ± 7 mL/kg/min) completed ~1 h of high-intensity intervals (EX1). Immediately and 120 min following EX1, subjects consumed one of three calorically-similar beverages (285-300 kcal) in a cross-over design: carbohydrate-only (CHO; 75 g per beverage), high-carbohydrate/low-protein (HCLP; 45 g CHO, 25 g Pro, 0.5 g fat), or low-carbohydrate/high-protein (LCHP; 8 g CHO, 55 g Pro, 4 g fat). After 4 h of recovery, subjects performed subsequent exercise (EX2; 20 min at 70% VO(2peak) + 20 km time-trial). Beverages were also consumed following EX2. Blood glucose levels (30 min after beverage ingestion) differed across all treatments (CHO > HCLP > LCHP; p < 0.05), and serum insulin was higher following CHO and HCLP ingestion versus LCHP. Peak quadriceps force, serum creatine kinase, muscle soreness, and fatigue/energy ratings measured pre- and post-exercise were not different between treatments. EX2 performance was not significantly different between CHO (48.5 ± 1.5 min), HCLP (48.8 ± 2.1 min) and LCHP (50.3 ± 2.7 min). Beverages containing similar caloric content but different proportions of carbohydrate/protein provided similar effects on muscle recovery and subsequent exercise performance in well-trained cyclists. PMID:22852050

  10. Effects of muscular and aqua aerobic combined exercise on metabolic indices in elderly women with metabolic syndrome.

    PubMed

    Yoo, Yong-Kwon; Kim, Soo-Keun; Song, Min-Sun

    2013-12-01

    The purpose of this study was to investigate the effects of muscle strengthening exercise using elastic thera-band and aquatic aerobic combined exercise on metabolic syndrome index in elderly with metabolic syndrome. Fifty-four were assigned to muscle strengthening exercise group (n = 19), aquatic aerobic exercise group (n = 19), and combined exercise group (n = 16). The muscle strength exercise, aquatic aerobic exercise and combined exercise were provided three times a week for 12 weeks. Metabolic syndrome indices[Fasting blood glucose, triglyceride, high density lipoprotein cholesterol (HDL-C), systolic blood pressure, diastolic blood pressure and waist circumference] were measured before and after the program. One-way ANOVA, paired t-test and two-way repeated ANOVA were used with the SPSS program for data analysis. There was a significant difference in triglyceride (p < .001), HDL-C (p = .010) and waist circumference (p = .016). Triglyceride and waist circumference was significantly decreased in combined group than muscle strength exercise group and aquatic exercise group. HDL-C was significantly increased in combined group than muscle strength exercise group. The results indicate that combined exercise was more effective in the improvement of dyslipidemia and abdominal obesity. PMID:25566424

  11. Changes in Voluntary Activation Assessed by Transcranial Magnetic Stimulation during Prolonged Cycling Exercise

    PubMed Central

    Perrey, Stephane; Temesi, John; Wuyam, Bernard; Levy, Patrick; Verges, Samuel; Millet, Guillaume Y.

    2014-01-01

    Maximal central motor drive is known to decrease during prolonged exercise although it remains to be determined whether a supraspinal deficit exists, and if so, when it appears. The purpose of this study was to evaluate corticospinal excitability and muscle voluntary activation before, during and after a 4-h cycling exercise. Ten healthy subjects performed three 80-min bouts on an ergocycle at 45% of their maximal aerobic power. Before exercise and immediately after each bout, neuromuscular function was evaluated in the quadriceps femoris muscles under isometric conditions. Transcranial magnetic stimulation was used to assess voluntary activation at the cortical level (VATMS), corticospinal excitability via motor-evoked potential (MEP) and intracortical inhibition by cortical silent period (CSP). Electrical stimulation of the femoral nerve was used to measure voluntary activation at the peripheral level (VAFNES) and muscle contractile properties. Maximal voluntary force was significantly reduced after the first bout (13±9%, P<0.01) and was further decreased (25±11%, P<0.001) at the end of exercise. CSP remained unchanged throughout the protocol. Rectus femoris and vastus lateralis but not vastus medialis MEP normalized to maximal M-wave amplitude significantly increased during cycling. Finally, significant decreases in both VATMS and VAFNES (∼8%, P<0.05 and ∼14%, P<0.001 post-exercise, respectively) were observed. In conclusion, reductions in VAFNES after a prolonged cycling exercise are partly explained by a deficit at the cortical level accompanied by increased corticospinal excitability and unchanged intracortical inhibition. When comparing the present results with the literature, this study highlights that changes at the cortical and/or motoneuronal levels depend not only on the type of exercise (single-joint vs. whole-body) but also on exercise intensity and/or duration. PMID:24586559

  12. Neuromuscular function following prolonged intense self-paced exercise in hot climatic conditions.

    PubMed

    Périard, Julien D; Cramer, Matthew N; Chapman, Phillip G; Caillaud, Corinne; Thompson, Martin W

    2011-08-01

    Muscle weakness following constant load exercise under heat stress has been associated with hyperthermia-induced central fatigue. However, evidence of central fatigue influencing intense self-paced exercise in the heat is lacking. The purpose of this investigation was to evaluate force production capacity and central nervous system drive in skeletal muscle pre- and post-cycle ergometer exercise in hot and cool conditions. Nine trained male cyclists performed a 20-s maximal voluntary isometric contraction (MVC) prior to (control) and following a 40-km time trial in hot (35°C) and cool (20°C) conditions. MVC force production and voluntary activation of the knee extensors was evaluated via percutaneous tetanic stimulation. In the cool condition, rectal temperature increased to 39.0°C and reached 39.8°C in the heat (P < 0.01). Following exercise in the hot and cool conditions, peak force declined by ~90 and ~99 N, respectively, compared with control (P < 0.01). Mean force decreased by 15% (hot) and 14% (cool) (P < 0.01 vs. control). Voluntary activation during the post-exercise MVC declined to 93.7% (hot) and 93.9% (cool) (P < 0.05 vs. control). The post-exercise decline in voluntary activation represented ~20% of the decrease in mean force production in both conditions. Therefore, the additional increase in rectal temperature did not exacerbate the loss of force production following self-paced exercise in the heat. The impairment in force production indicates that the fatigue exhibited by the quadriceps is mainly of peripheral origin and a consequence of the prolonged contractile activity associated with exercise. PMID:21188412

  13. Changes in voluntary activation assessed by transcranial magnetic stimulation during prolonged cycling exercise.

    PubMed

    Jubeau, Marc; Rupp, Thomas; Perrey, Stephane; Temesi, John; Wuyam, Bernard; Levy, Patrick; Verges, Samuel; Millet, Guillaume Y

    2014-01-01

    Maximal central motor drive is known to decrease during prolonged exercise although it remains to be determined whether a supraspinal deficit exists, and if so, when it appears. The purpose of this study was to evaluate corticospinal excitability and muscle voluntary activation before, during and after a 4-h cycling exercise. Ten healthy subjects performed three 80-min bouts on an ergocycle at 45% of their maximal aerobic power. Before exercise and immediately after each bout, neuromuscular function was evaluated in the quadriceps femoris muscles under isometric conditions. Transcranial magnetic stimulation was used to assess voluntary activation at the cortical level (VATMS), corticospinal excitability via motor-evoked potential (MEP) and intracortical inhibition by cortical silent period (CSP). Electrical stimulation of the femoral nerve was used to measure voluntary activation at the peripheral level (VAFNES) and muscle contractile properties. Maximal voluntary force was significantly reduced after the first bout (13 9%, P<0.01) and was further decreased (25 11%, P<0.001) at the end of exercise. CSP remained unchanged throughout the protocol. Rectus femoris and vastus lateralis but not vastus medialis MEP normalized to maximal M-wave amplitude significantly increased during cycling. Finally, significant decreases in both VATMS and VAFNES (? 8%, P<0.05 and ? 14%, P<0.001 post-exercise, respectively) were observed. In conclusion, reductions in VAFNES after a prolonged cycling exercise are partly explained by a deficit at the cortical level accompanied by increased corticospinal excitability and unchanged intracortical inhibition. When comparing the present results with the literature, this study highlights that changes at the cortical and/or motoneuronal levels depend not only on the type of exercise (single-joint vs. whole-body) but also on exercise intensity and/or duration. PMID:24586559

  14. A clinically relevant BTX-A injection protocol leads to persistent weakness, contractile material loss, and an altered mRNA expression phenotype in rabbit quadriceps muscles.

    PubMed

    Fortuna, Rafael; Vaz, Marco A; Sawatsky, Andrew; Hart, David A; Herzog, Walter

    2015-07-16

    Botulinum toxin type-A (BTX-A) injections have become a common treatment modality for patients suffering from muscle spasticity. Despite its benefits, BTX-A treatments have been associated with adverse effects on target muscles. Currently, application of BTX-A is largely based on clinical experience, and research quantifying muscle structure following BTX-A treatment has not been performed systematically. The purpose of this study was to evaluate strength, muscle mass, and contractile material six months following a single or repeated (2 and 3) BTX-A injections into the quadriceps femoris of New Zealand white rabbits. Twenty three skeletally mature rabbits were divided into four groups: experimental group rabbits received 1, 2, or 3 injections at intervals of 3 months (1-BTX-A, 2-BTX-A, 3-BTX-A, respectively) while control group rabbits received volume-matched saline injections. Knee extensor strength, quadriceps muscle mass, and quadriceps contractile material of the experimental group rabbits were expressed as a percentage change relative to the control group rabbits. One-way ANOVA was used to determine group differences in outcome measures (α=0.05). Muscle strength and contractile material were significantly reduced in experimental compared to control group rabbits but did not differ between experimental groups. Muscle mass was the same in experimental BTX-A and control group rabbits. We concluded from these results that muscle strength and contractile material do not fully recover within six months of BTX-A treatment. PMID:26087882

  15. Muscle and intensity based hamstring exercise classification in elite female track and field athletes: implications for exercise selection during rehabilitation

    PubMed Central

    Tsaklis, Panagiotis; Malliaropoulos, Nikos; Mendiguchia, Jurdan; Korakakis, Vasileios; Tsapralis, Kyriakos; Pyne, Debasish; Malliaras, Peter

    2015-01-01

    Background Hamstring injuries are common in many sports, including track and field. Strains occur in different parts of the hamstring muscle but very little is known about whether common hamstring loading exercises specifically load different hamstring components. The purpose of this study was to investigate muscle activation of different components of the hamstring muscle during common hamstring loading exercises. Methods Twenty elite female track and field athletes were recruited into this study, which had a single-sample, repeated-measures design. Each athlete performed ten hamstring loading exercises, and an electromyogram (EMG) was recorded from the biceps femoris and semitendinosus components of the hamstring. Hamstring EMG during maximal voluntary isometric contraction (MVIC) was used to normalize the mean data across ten repetitions of each exercise. An electrogoniometer synchronized to the EMG was used to determine whether peak EMG activity occurred during muscle-tendon unit lengthening, shortening, or no change in length. Mean EMG values were compared between the two recording sites for each exercise using the Student’s t-test. Results The lunge, dead lift, and kettle swings were low intensity (<50% MVIC) and all showed higher EMG activity for semitendinosus than for biceps femoris. Bridge was low but approaching medium intensity, and the TRX, hamstring bridge, and hamstring curl were all medium intensity exercises (≥50% or <80% MVIC). The Nordic, fitball, and slide leg exercises were all high intensity exercises. Only the fitball exercise showed higher EMG activity in the biceps femoris compared with the semitendinosus. Only lunge and kettle swings showed peak EMG in the muscle-tendon unit lengthening phase and both these exercises involved faster speed. Conclusion Some exercises selectively activated the lateral and medial distal hamstrings. Low, medium, and high intensity exercises were demonstrated. This information enables the clinician, strength and conditioning coach and physiotherapist to better understand intensity- and muscle-specific activation during hamstring muscle rehabilitation. Therefore, these results may help in designing progressive strengthening and rehabilitation and prevention programs. PMID:26170726

  16. Skeletal muscle adiposity is associated with physical activity, exercise capacity and fibre shift in COPD

    PubMed Central

    Maddocks, Matthew; Shrikrishna, Dinesh; Vitoriano, Simone; Natanek, Samantha A.; Tanner, Rebecca J.; Hart, Nicholas; Kemp, Paul R.; Moxham, John; Polkey, Michael I.; Hopkinson, Nicholas S.

    2014-01-01

    Quadriceps muscle phenotype varies widely between patients with chronic obstructive pulmonary disease (COPD) and cannot be determined without muscle biopsy. We hypothesised that measures of skeletal muscle adiposity could provide noninvasive biomarkers of muscle quality in this population. In 101 patients and 10 age-matched healthy controls, mid-thigh cross-sectional area, percentage intramuscular fat and skeletal muscle attenuation were calculated using computed tomography images and standard tissue attenuation ranges: fat -190– -30 HU; skeletal muscle -29–150 HU. Mean±sd percentage intramuscular fat was higher in the patient group (6.7±3.5% versus 4.3±1.2%, p = 0.03). Both percentage intramuscular fat and skeletal muscle attenuation were associated with physical activity level, exercise capacity and type I fibre proportion, independent of age, mid-thigh cross-sectional area and quadriceps strength. Combined with transfer factor of the lung for carbon monoxide, these variables could identify >80% of patients with fibre type shift with >65% specificity (area under the curve 0.83, 95% CI 0.72–0.95). Skeletal muscle adiposity assessed by computed tomography reflects multiple aspects of COPD related muscle dysfunction and may help to identify patients for trials of interventions targeted at specific muscle phenotypes. PMID:24993908

  17. Chronic eccentric cycling improves quadriceps muscle structure and maximum cycling power.

    PubMed

    Leong, C H; McDermott, W J; Elmer, S J; Martin, J C

    2014-06-01

    An interesting finding from eccentric exercise training interventions is the presence of muscle hypertrophy without changes in maximum concentric strength and/or power. The lack of improvements in concentric strength and/or power could be due to long lasting suppressive effects on muscle force production following eccentric training. Thus, improvements in concentric strength and/or power might not be detected until muscle tissue has recovered (e. g., several weeks post-training). We evaluated alterations in muscular structure (rectus-femoris, RF, and vastus lateralis, VL, thickness and pennation angles) and maximum concentric cycling power (Pmax) 1-week following 8-weeks of eccentric cycling training (2×/week; 5-10.5 min; 20-55% of Pmax). Pmax was assessed again at 8-weeks post-training. At 1 week post-training, RF and VL thickness increased by 24±4% and 13±2%, respectively, and RF and VL pennation angles increased by 31±4% and 13±1%, respectively (all P<0.05). Compared to pre-training values, Pmax increased by 5±1% and 9±2% at 1 and 8 weeks post-training, respectively (both P<0.05). These results demonstrate that short-duration high-intensity eccentric cycling can be a time-effective intervention for improving muscular structure and function in the lower body of healthy individuals. The larger Pmax increase detected at 8-weeks post-training implies that sufficient recovery might be necessary to fully detect changes in muscular power after eccentric cycling training. PMID:24234011

  18. Comparison between the Effects of Horseback Riding Exercise and Trunk Stability Exercise on the Balance of Normal Adults

    PubMed Central

    Kim, Hyeon Su; Lee, Chae-Woo; Lee, In-Sil

    2014-01-01

    [Purpose] The aim of this study was to compare the effects of horseback riding exercise and trunk stability exercise on static and dynamic balance in normal adults. [Subjects and Methods] Twenty-two normal adults residing in communities were randomly divided into a horseback riding exercise group and a trunk stability exercise group, and they conducted exercise for eight weeks. [Results] Sway times of the COG (center of gravity) decreased significantly, and the A-P (anterior-posterior) and M-L (medial-lateral) velocities significantly decreased in both groups. A comparison of sway times of the COG after the intervention between the two groups revealed that the horseback riding exercise group showed larger decreases than the trunk stability exercise group. [Conclusion] In terms of the musculoskeletal factor, horseback riding may result in functional improvement and increased stability, and it may stimulate proprioceptive sense input in neurological terms. It is therefore considered a composite exercise method that may strengthen the two factors simultaneously. PMID:25276009

  19. Strengthening Bridges with Prestressed CFRP Strips

    NASA Astrophysics Data System (ADS)

    Siwowski, Tomasz; Żółtowski, Piotr

    2012-06-01

    Limitation of bridge's carrying bearing capacity due to aging and deterioration is a common problem faced by road administration and drivers. Rehabilitation of bridges including strengthening may be applied in order to maintain or upgrade existing bridge parameters. The case studies of strengthening of two small bridges with high modulus prestressed CFRP strips have been presented in the paper. The first one - reinforced concrete slab bridge - and the other - composite steel-concrete girder bridge - have been successfully upgraded with quite new technology. In both cases the additional CFRP reinforcement let increasing of bridge carrying capacity from 15 till 40 metric tons. The CFRP strip prestressing system named Neoxe Prestressing System (NPS), developed by multi-disciplinary team and tested at full scale in Rzeszow University of Technology, has been also described in the paper.

  20. Evaluation of Central and Peripheral Fatigue in the Quadriceps Using Fractal Dimension and Conduction Velocity in Young Females

    PubMed Central

    Beretta-Piccoli, Matteo; D’Antona, Giuseppe; Barbero, Marco; Fisher, Beth; Dieli-Conwright, Christina M.; Clijsen, Ron; Cescon, Corrado

    2015-01-01

    Purpose Over the past decade, linear and non-linear surface electromyography descriptors for central and peripheral components of fatigue have been developed. In the current study, we tested fractal dimension (FD) and conduction velocity (CV) as myoelectric descriptors of central and peripheral fatigue, respectively. To this aim, we analyzed FD and CV slopes during sustained fatiguing contractions of the quadriceps femoris in healthy humans. Methods A total of 29 recreationally active women (mean age±standard deviation: 24±4 years) and two female elite athletes (one power athlete, age 24 and one endurance athlete, age 30 years) performed two knee extensions: (1) at 20% maximal voluntary contraction (MVC) for 30 s, and (2) at 60% MVC held until exhaustion. Surface EMG signals were detected from the vastus lateralis and vastus medialis using bidimensional arrays. Results Central and peripheral fatigue were described as decreases in FD and CV, respectively. A positive correlation between FD and CV (R=0.51, p<0.01) was found during the sustained 60% MVC, probably as a result of simultaneous motor unit synchronization and a decrease in muscle fiber CV during the fatiguing task. Conclusions Central and peripheral fatigue can be described as changes in FD and CV, at least in young, healthy women. The significant correlation between FD and CV observed at 60% MVC suggests that a mutual interaction between central and peripheral fatigue can arise during submaximal isometric contractions. PMID:25880369

  1. Linearity and reliability of the mechanomyographic amplitude versus dynamic torque relationships for the superficial quadriceps femoris muscles.

    PubMed

    Stock, Matthew S; Beck, Travis W; Defreitas, Jason M; Dillon, Michael A

    2010-03-01

    The purpose of this investigation was to examine the linearity and reliability of the mechanomyographic (MMG) amplitude versus dynamic torque relationships for the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM) muscles. Nine healthy men and 11 healthy women performed submaximal to maximal, concentric, isokinetic muscle actions of the leg extensors at 30 degrees s(-1) on two occasions. Surface MMG signals were detected from the VL, RF, and VM of the dominant thigh during both trials. The ranges of the coefficients of determination for the MMG amplitude versus dynamic torque relationships were 0.01-0.94 for the VL, 0.01-0.84 for the RF, and 0.19-0.96 for the VM. The intraclass correlation coefficients for the linear MMG amplitude versus torque slope coefficients were 0.823 (VL), 0.792 (RF), and 0.927 (VM). These results indicate that, when analyzed for individual subjects, the MMG amplitude versus dynamic torque relationships demonstrated inconsistent linearity. When using MMG in the clinical setting, dynamic muscle actions of the superficial quadriceps femoris muscles do not appear to be appropriate for assessing changes in muscle function during strength training. PMID:19813206

  2. Effects of prolonged patellar tendon vibration on force steadiness in quadriceps femoris during force-matching task.

    PubMed

    Saito, Akira; Ando, Ryosuke; Akima, Hiroshi

    2016-01-01

    The quadriceps femoris (QF) muscle group plays an essential role in human movement, such as standing, walking and running. The ability to maintain a steady force during physical activity of the human lower limb is important for mobility, postural control and balance. Although prolonged mechanical vibration of the muscle-tendon unit can moderate the efficacy of synaptic input from Ia afferent onto the ?-motor neuron pathway, the effect of prolonged tendon vibration on fluctuations of knee extensor force has received little attention. The purpose of the present study was to examine the effects of prolonged patellar tendon vibration on the force steadiness of the QF muscle. Nine healthy men performed a submaximal force-matching task involving isometric knee extension before and after patellar tendon vibration or quiet seated rest (n=7, control condition) for 30min. The target force was 2.5, 10 and 30% of maximal voluntary contraction (MVC). Surface electromyography (EMG) of the four QF synergists was recorded and normalized to EMG amplitude during the MVC. The knee extension force and the EMG amplitude of vastus medialis during the MVC were significantly reduced after the vibration, but did not significantly decrease in the control condition. Fluctuations of force and normalized EMG of individual QF muscles at each submaximal force level did not significantly change after the vibration. We conclude that prolonged patellar tendon vibration does not influence the force steadiness of the QF muscle during an isometric force-matching task. PMID:26419664

  3. Acute effects of static and dynamic stretching on hamstring eccentric isokinetic strength and unilateral hamstring to quadriceps strength ratios.

    PubMed

    Ayala, Francisco; De Ste Croix, Mark; Sainz De Baranda, Pilar; Santonja, Fernando

    2013-01-01

    The main purposes of this study were to investigate the acute effects of static and dynamic lower limb stretching routines: (a) on peak torque, total external work and joint angle at peak torque of the hamstrings during maximal eccentric isokinetic leg flexion; (b) on unilateral hamstring to quadriceps (H/Q) strength ratios; as well as (c) to determine whether static and dynamic routines elicit similar responses. A total of 49 active adults completed the following intervention protocols in a randomised order on separate days: (a) non-stretching (control condition), (b) static stretching, and (c) dynamic stretching. After the stretching or control intervention, eccentric isokinetic peak torque, the angle of peak torque and total external work were assessed with participants prone at 1.04 and 3.14 rad · s(-1). Unilateral strength ratios of the knee were also recorded. Measures were compared via a fully-within-groups factorial analysis of variance (ANOVA). There were no main effects for eccentric isokinetic peak torque, angle of peak torque, total external work and unilateral H/Q strength ratios. The results suggest that dynamic and static stretching has no influence on eccentric strength profile and unilateral H/Q strength ratios and hence both forms of stretching do not reduce these two primary risk factors for muscle injury. PMID:23230900

  4. Reconstruction of the medial patellofemoral ligament using autologous graft from quadriceps tendon to treat recurrent patellar dislocation☆

    PubMed Central

    Calapodopulos, Constantino Jorge; Nogueira, Marcelo Corvino; Eustáquio, José Martins Juliano; Calapodopulos Júnior, Constantino Jorge; Rodrigues, Oreston Alves

    2016-01-01

    Objective The objective of this study was to evaluate the efficacy of the surgical technique using the quadriceps tendon as a graft in static reconstruction of the medial patellofemoral ligament. Methods This was a prospective case series study in which the participants were 22 patients with a diagnosis of recurrent patellar dislocation without any other anatomical alterations that required surgical treatment. The functional results from the technique were evaluated using clinical data and the Lysholm questionnaire, one year after the operation. Results It was observed that the patients were predominantly female (86%) and under 21 years of age (73%), just like in the literature. At the first annual return after the surgery, there was no significant pain on medium efforts, no loss of range of motion and a positive apprehension test. According to the questionnaire used, the results were graded as good. The patients who reported having severe pain on greater effort were involved in employment-related legal disputes. Conclusion This technique showed low morbidity and good functional results over the short term. PMID:27069888

  5. Effect of a short time concentric versus eccentric training program on electromyography activity and peak torque of quadriceps.

    PubMed

    Carvalho, Alberto; Caserotti, Paolo; Carvalho, Carlos; Abade, Eduardo; Sampaio, Jaime

    2014-06-28

    The purpose of this study was to examine the effect of an 8-week concentric (CON) versus eccentric (ECC) isokinetic training program on the electromyography (EMG) signal amplitude of vastus medialis (VM), vastus lateralis (VL) and rectus femoris (RF). Also, the isometric (ISO) and dynamic maximum strength of the knee extensors were assessed. Eighteen physically healthy male subjects (age 22 ± 1 years, body height 177 ± 4 cm, body mass 73 ± 7 kg) performed four weeks of unilateral CON isokinetic training for the quadriceps of the dominant leg on a REV9000 dynamometer. At the end of the fourth week, the sample was divided into two groups, with one group performing additional four weeks of unilateral ECC training and the other continuing with CON training. The training sessions consisted of three sets of ten maximal repetitions at a velocity of 60ºs-1, three days per week for eight weeks. The results showed that CON and ECC groups improved the peak torque in all types of contractions. Also, both groups presented increases in the avgEMG for VL, VM and RF. The present investigation showed that CON training elicited increases of the ISO peak torque and VM avgEMG in the CON contraction. Additionally, significant gains were reported after the ECC training on the VM avgEMG in all contractions and RM avgEMG in CON contraction. PMID:25114726

  6. The highest antagonistic coactivation of the vastus intermedius muscle among quadriceps femoris muscles during isometric knee flexion.

    PubMed

    Saito, Akira; Watanabe, Kohei; Akima, Hiroshi

    2013-08-01

    Although the possibility that the vastus intermedius (VI) muscle contributes to flexion of the knee joint has been suggested previously, the detail of its functional role in knee flexion is not well understood. The purpose of this study was to examine the antagonist coactivation of VI during isometric knee flexion. Thirteen men performed 25-100% of maximal voluntary contraction (MVC) at 90°, 120°, and 150° knee joint angles. Surface electromyography (EMG) of the four individual muscles in the quadriceps femoris (QF) was recorded and normalized by the EMG signals during isometric knee extension at MVC. Cross-talk on VI EMG signal was assessed based on the median frequency response to selective cooling of hamstring muscles. Normalized EMG of the VI was significantly higher than that of the other synergistic QF muscles at each knee joint angle (all P<0.05) with minimum cross-talk from the hamstrings to VI. There were significant correlations between the EMG signal of the hamstrings and VI (r=0.55-0.85, P<0.001). These results suggest that VI acts as a primary antagonistic muscle of QF during knee flexion, and that VI is presumably a main contributor to knee joint stabilization. PMID:23489717

  7. Cross-correlation analyses of mechanomyographic signals from the superficial quadriceps femoris muscles during concentric and eccentric isokinetic muscle actions.

    PubMed

    Cramer, J T; Housh, T J; Weir, J P; Ebersole, K T; Perry-Rana, S R; Bull, A J; Johnson, G O

    2003-01-01

    The purpose of this investigation was to examine the cross-correlation coefficients of mechanomyographic (MMG) signals recorded from the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM) muscles during maximal, concentric and eccentric isokinetic muscle actions. Eleven females (mean +/- SD age = 21 +/- 1 yr) performed such muscle actions of the leg extensors at 60 degrees.s-1 on a Cybex 6000 dynamometer. MMG signals were sampled simultaneously from the VL, RF, and VM at 1000 Hz by piezoelectric crystal contact sensors. Peak composite cross-correlation coefficients (rxy) and common variances (rxy2) were determined for each between-muscle comparison (VL vs. RF, VL vs. VM, and RF vs. VM). The results indicated peak cross-correlation coefficients ranging from rxy = 0.38 to 0.52, while common variances (rxy2) between signals ranged from 14% to 27% across all time lags (tau = -50...). In conjunction with other studies, these results suggested that despite the potential for some cross-talk, MMG measurements can be used to examine differences between the patterns of MMG amplitude and frequency responses of the superficial quadriceps femoris muscles. PMID:12964257

  8. Pumping Iron in Australia: Prevalence, Trends and Sociodemographic Correlates of Muscle Strengthening Activity Participation from a National Sample of 195,926 Adults

    PubMed Central

    Pedisic, Zeljko; van Uffelen, Jannique G. Z.; Charity, Melanie J.; Harvey, Jack T.; Banting, Lauren K.; Vergeer, Ineke; Biddle, Stuart J. H.; Eime, Rochelle M.

    2016-01-01

    Objective The current Australian Physical Activity Guidelines recommend that adults engage in regular muscle-strengthening activity (e.g. strength or resistance training). However, public health surveillance studies describing the patterns and trends of population-level muscle-strengthening activity participation are sparse. The aim of this study is to examine the prevalence, trends and sociodemographic correlates of muscle-strengthening activity participation in a national-representative sample of Australians aged 15 years and over. Methods Between 2001 and 2010, quarterly cross-sectional national telephone surveys were conducted as part of the Australian Sports Commission's 'Exercise, Recreation and Sport Survey'. Pooled population-weighted proportions were calculated for reporting: [i] no muscle-strengthening activity; [ii] insufficient muscle-strengthening activity, and [iii] sufficient muscle-strengthening activity. Associations with sociodemographic variables were assessed using multiple logistic regression analyses. Results Out of 195,926 participants, aged 15–98 years, only 10.4% (95% CI: 10.1–10.7) and 9.3% (95% CI: 9.1–9.5) met the muscle-strengthening activity recommendations in the past two weeks and in the past year, respectively. Older adults (50+ years), and those living in socioeconomically disadvantaged, outer regional/remote areas and with lower education were less likely to report sufficient muscle-strengthening activity (p<0.001). Over the 10-year monitoring period, there was a significant increase in the prevalence of sufficient muscle-strengthening activity (6.4% to 12.0%, p-value for linear trend <0.001). Conclusions A vast majority of Australian adults did not engage in sufficient muscle-strengthening activity. There is a need for public health strategies to support participation in muscle-strengthening activity in this population. Such strategies should target older and lower educated adults, and those living in socioeconomically disadvantaged, outer regional/remote and areas. PMID:27119145

  9. Strengthening an affiliation without a merger.

    PubMed

    Hegwer, Laura Ramos

    2015-04-01

    Froedtert Health and the Medical College of Wisconsin have created a shared governance structure with joint committees focused on value, IT, marketing, strategic planning, and other areas. A new funds-flow model shifts a percentage of the health system's bottom line to the medical college to support physician recruitment,joint initiatives, academic programs, and a strategic reserve. The strengthened affiliation has enhanced the ability of the organizations to engage in accountable care and population health initiatives, among other benefits. PMID:26665524

  10. Process for strengthening silicon based ceramics

    DOEpatents

    Kim, Hyoun-Ee; Moorhead, A. J.

    1993-01-01

    A process for strengthening silicon based ceramic monolithic materials and omposite materials that contain silicon based ceramic reinforcing phases that requires that the ceramic be exposed to a wet hydrogen atmosphere at about 1400.degree. C. The process results in a dense, tightly adherent silicon containing oxide layer that heals, blunts , or otherwise negates the detrimental effect of strength limiting flaws on the surface of the ceramic body.

  11. Process for strengthening silicon based ceramics

    DOEpatents

    Kim, Hyoun-Ee; Moorhead, A. J.

    1993-04-06

    A process for strengthening silicon based ceramic monolithic materials and omposite materials that contain silicon based ceramic reinforcing phases that requires that the ceramic be exposed to a wet hydrogen atmosphere at about 1400.degree. C. The process results in a dense, tightly adherent silicon containing oxide layer that heals, blunts , or otherwise negates the detrimental effect of strength limiting flaws on the surface of the ceramic body.

  12. Supraspinal fatigue after normoxic and hypoxic exercise in humans.

    PubMed

    Goodall, Stuart; González-Alonso, José; Ali, Leena; Ross, Emma Z; Romer, Lee M

    2012-06-01

    Inadequate cerebral O₂ availability has been proposed to be an important contributing factor to the development of central fatigue during strenuous exercise. Here we tested the hypothesis that supraspinal processes of fatigue would be increased after locomotor exercise in acute hypoxia compared to normoxia, and that such change would be related to reductions in cerebral O₂ delivery and tissue oxygenation. Nine endurance-trained cyclists completed three constant-load cycling exercise trials at ∼80% of maximal work rate: (1) to the limit of tolerance in acute hypoxia; (2) for the same duration but in normoxia (control); and (3) to the limit of tolerance in normoxia. Throughout each trial, prefrontal cortex tissue oxygenation and middle cerebral artery blood velocity (MCAV) were assessed using near-infrared spectroscopy and trans-cranial Doppler sonography, respectively. Cerebral O₂ delivery was calculated as the product of arterial O₂ content and MCAV. Before and immediately after each trial, twitch responses to supramaximal femoral nerve stimulation and transcranial magnetic stimulation were obtained to assess neuromuscular and cortical function, respectively. Exercise time was reduced by 54%in hypoxia compared to normoxia (3.6 ± 1.3 vs. 8.1 ± 2.9 min; P<0.001). Cerebral O₂ delivery,cerebral oxygenation and maximum O₂ uptake were reduced whereas muscle electromyographic activity was increased in hypoxia compared to control (P <0.05).Maximum voluntary force and potentiated quadriceps twitch force were decreased below baseline after exercise in each trial;the decreases were greater in hypoxia compared to control (P<0.001), but were not different in the exhaustive trials (P>0.05). Cortical voluntary activation was also decreased after exercise in all trials, but the decline in hypoxia (Δ18%) was greater than in the normoxic trials (Δ5-9%)(P <0.05). The reductions in cortical voluntary activation were paralleled by reductions in cerebral O₂ delivery. The results suggest that curtailment of exercise performance in acute severe hypoxia is due, in part, to failure of drive from the motor cortex, possibly as a consequence of diminished O₂ availability in the brain. PMID:22473785

  13. Supraspinal fatigue after normoxic and hypoxic exercise in humans

    PubMed Central

    Goodall, Stuart; González-Alonso, José; Ali, Leena; Ross, Emma Z; Romer, Lee M

    2012-01-01

    Inadequate cerebral O2 availability has been proposed to be an important contributing factor to the development of central fatigue during strenuous exercise. Here we tested the hypothesis that supraspinal processes of fatigue would be increased after locomotor exercise in acute hypoxia compared to normoxia, and that such change would be related to reductions in cerebral O2 delivery and tissue oxygenation. Nine endurance-trained cyclists completed three constant-load cycling exercise trials at ∼80% of maximal work rate: (1) to the limit of tolerance in acute hypoxia; (2) for the same duration but in normoxia (control); and (3) to the limit of tolerance in normoxia. Throughout each trial, prefrontal cortex tissue oxygenation and middle cerebral artery blood velocity (MCAV) were assessed using near-infrared spectroscopy and transcranial Doppler sonography, respectively. Cerebral O2 delivery was calculated as the product of arterial O2 content and MCAV. Before and immediately after each trial, twitch responses to supramaximal femoral nerve stimulation and transcranial magnetic stimulation were obtained to assess neuromuscular and cortical function, respectively. Exercise time was reduced by 54% in hypoxia compared to normoxia (3.6 ± 1.3 vs. 8.1 ± 2.9 min; P < 0.001). Cerebral O2 delivery, cerebral oxygenation and maximum O2 uptake were reduced whereas muscle electromyographic activity was increased in hypoxia compared to control (P < 0.05). Maximum voluntary force and potentiated quadriceps twitch force were decreased below baseline after exercise in each trial; the decreases were greater in hypoxia compared to control (P < 0.001), but were not different in the exhaustive trials (P > 0.05). Cortical voluntary activation was also decreased after exercise in all trials, but the decline in hypoxia (Δ18%) was greater than in the normoxic trials (Δ5–9%) (P < 0.05). The reductions in cortical voluntary activation were paralleled by reductions in cerebral O2 delivery. The results suggest that curtailment of exercise performance in acute severe hypoxia is due, in part, to failure of drive from the motor cortex, possibly as a consequence of diminished O2 availability in the brain. PMID:22473785

  14. Strengthening health systems by health sector reforms

    PubMed Central

    Senkubuge, Flavia; Modisenyane, Moeketsi; Bishaw, Tewabech

    2014-01-01

    Background The rising burden of disease and weak health systems are being compounded by the persistent economic downturn, re-emerging diseases, and violent conflicts. There is a growing recognition that the global health agenda needs to shift from an emphasis on disease-specific approaches to strengthening of health systems, including dealing with social, environmental, and economic determinants through multisectoral responses. Methods A review and analysis of data on strengthening health sector reform and health systems was conducted. Attention was paid to the goal of health and interactions between health sector reforms and the functions of health systems. Further, we explored how these interactions contribute toward delivery of health services, equity, financial protection, and improved health. Findings Health sector reforms cannot be developed from a single global or regional policy formula. Any reform will depend on the country's history, values and culture, and the population's expectations. Some of the emerging ingredients that need to be explored are infusion of a health systems agenda; development of a comprehensive policy package for health sector reforms; improving alignment of planning and coordination; use of reliable data; engaging ‘street level’ policy implementers; strengthening governance and leadership; and allowing a holistic and developmental approach to reforms. Conclusions The process of reform needs a fundamental rather than merely an incremental and evolutionary change. Without radical structural and systemic changes, existing governance structures and management systems will continue to fail to address the existing health problems. PMID:24560261

  15. Assessing exercise limitation using cardiopulmonary exercise testing.

    PubMed

    Stickland, Michael K; Butcher, Scott J; Marciniuk, Darcy D; Bhutani, Mohit

    2012-01-01

    The cardiopulmonary exercise test (CPET) is an important physiological investigation that can aid clinicians in their evaluation of exercise intolerance and dyspnea. Maximal oxygen consumption ([Formula: see text]) is the gold-standard measure of aerobic fitness and is determined by the variables that define oxygen delivery in the Fick equation ([Formula: see text] = cardiac output × arterial-venous O(2) content difference). In healthy subjects, of the variables involved in oxygen delivery, it is the limitations of the cardiovascular system that are most responsible for limiting exercise, as ventilation and gas exchange are sufficient to maintain arterial O(2) content up to peak exercise. Patients with lung disease can develop a pulmonary limitation to exercise which can contribute to exercise intolerance and dyspnea. In these patients, ventilation may be insufficient for metabolic demand, as demonstrated by an inadequate breathing reserve, expiratory flow limitation, dynamic hyperinflation, and/or retention of arterial CO(2). Lung disease patients can also develop gas exchange impairments with exercise as demonstrated by an increased alveolar-to-arterial O(2) pressure difference. CPET testing data, when combined with other clinical/investigation studies, can provide the clinician with an objective method to evaluate cardiopulmonary physiology and determination of exercise intolerance. PMID:23213518

  16. Writing Exercises from "Exercise Exchange." Volume II.

    ERIC Educational Resources Information Center

    Duke, Charles R., Ed.

    Reflecting current practices in the teaching of writing, the exercises in this compilation were drawn from the journal "Exercise Exchange." The articles are arranged into six sections: sources for writing; prewriting; modes for writing; writing and reading; language, mechanics, and style; and revising, responding, and evaluating. Among the topics…

  17. Does Exercise Intensity Matter?

    ERIC Educational Resources Information Center

    Pollock, Cynthia L.

    1992-01-01

    Examines the need for exercise intensity to become physically fit, concluding that intensity is not important for improving health, only for improving performance. What is important is routinely performing some sort of exercise. (GLR)

  18. Exercise and Physical Fitness

    MedlinePLUS

    ... Increase your chances of living longer Fitting regular exercise into your daily schedule may seem difficult at ... fine. The key is to find the right exercise for you. It should be fun and should ...

  19. Exercise for Seniors

    MedlinePLUS

    Exercise and physical activity are good for just about everyone, including older adults. There are four main ... jogging, dancing, swimming, and biking are examples. Strength exercises make your muscles stronger. Lifting weights or using ...

  20. Clinical Applications for Exercise.

    ERIC Educational Resources Information Center

    Goldstein, David

    1989-01-01

    Patients with chronic conditions such as coronary artery disease, hypertension, diabetes, and obesity might benefit from prescribed exercise. Although exercise does not reverse pathologic changes, it may play a role in disease management. (JD)

  1. Exercise and HIV

    MedlinePLUS

    ... sugar down. Cardiovascular exercise means increasing oxygenation and heart rate while moving large muscle groups continuously for at least 30 minutes. Activities such as brisk walking, jogging, dancing, bicycling or swimming can be considered cardiovascular exercise. ...

  2. Easy Exercises for Teens

    MedlinePLUS

    ... third component of well-rounded exercise. Check out yoga as one way to stay flexible. You can ... Sports and Exercise Safety Stretching Dynamic Stretching (Video) Yoga Welcome Home Yoga (Video) Study Break Yoga (Video) ...

  3. Why Exercise Is Cool

    MedlinePLUS

    ... put you in a better mood. When you exercise, your brain releases chemicals called endorphins (say: en-DOR-finz), which may make you feel happier. It's just another reason why exercise is cool! Reviewed by: Mary L. Gavin, MD ...

  4. Exercise and Asthma

    MedlinePLUS

    ... doing more exercise! In athletes, another problem called vocal cord dysfunction (VCD) can occur, and seems a lot like exercise-induced asthma. The vocal cords are located in the throat, at the opening ...

  5. Exercise and Osteoporosis

    MedlinePLUS

    ... in calcium and vitamin D. Include regular weight-bearing exercise in your lifestyle. Stop smoking. Limit how ... be stronger if you are physically active. Weight-bearing exercises, done three to four times a week, ...

  6. Exercising with Osteoarthritis

    MedlinePLUS

    ... people with osteoarthritis benefit from regular exercise and physical activity. For people with osteoarthritis, regular exercise can help: l Maintain healthy and strong muscles l Preserve joint mobility l Maintain range of motion l Improve sleep ...

  7. Facial cooling-induced bradycardia: attenuating effect of central command at exercise onset.

    PubMed

    Smith, J C; Stephens, D P; Winchester, P K; Williamson, J W

    1997-03-01

    Facial cooling (FC) elicits a marked bradycardia at rest that appears to be reduced during exercise. This study was done to delineate the effects of exercise mediated central command from those of muscle afferent feedback and sympathetic stimulation on the attenuation of the bradycardic effect of FC during the onset of exercise. Ten healthy subjects (26 +/- 2 yr) were exposed to FC under five different conditions: 1) seated rest on the cycle ergometer, 2) onset of mild exercise (resting HR + 20 beats.min-1), 3) onset of moderate exercise (resting HR + 50 beats.min-1), 4) seated rest on the ergometer during electrical stimulation, and 5) seated rest on the ergometer during a cold immersion test (CT) (one hand immersed in an ice slurry at 0 degree C). The two exercise intensities were presumed to provide different degrees of central command. Electrical stimulation of the quadriceps was assumed to provide isolated muscle afferent feedback, while the CT served as a sympathetic stimulus. Beat-by-beat data were recorded for HR and mean arterial blood pressure for the duration of each test (50 s), and a rating of perceived pain was taken after each FC. FC elicited significant increases in mean arterial pressure during mild and moderate exercise compared with resting control (P < 0.05) and during moderate exercise compared to exercise without FC (P < 0.05). Mean decreases in HR during FC were similar for resting control (-12 +/- 3 beats.min-1), electrical stimulation (-10 +/- 3 beats.min-1), and CT (-9 +/- 3 beats.min-1). The HR response to FC during mild exercise (-7 +/- 2 beats.min-1) was significantly different (P < 0.05) from the rest condition; however, there was no significant bradycardia (-2 +/- 2 beats.min-1; P > 0.05) during onset of moderate exercise. These findings suggest that the magnitude of cold face-induced bradycardia may be attenuated at exercise onset by neural signals related to the higher levels of central motor command associated with heavier exercise. PMID:9139170

  8. Biomechanics of front and back squat exercises

    NASA Astrophysics Data System (ADS)

    Braidot, A. A.; Brusa, M. H.; Lestussi, F. E.; Parera, G. P.

    2007-11-01

    Squat constitutes one of the most popular exercises to strengthen the muscles of the lower limbs. It is considered one of the most widely spread exercises for muscle sport training and is part of the competition movements comprised within olympic weight-lifting. In physical rehabilitation, squats are used for muscular recovery after different injuries of the lower limbs, especially the knee. In previous anterior cruciate ligament injuries, the mini-squats are generally used, in a knee flexion motion range from 0° to 50° because in this range the shear forces, the tibiofemoral and patellofemoral compression forces decrease related to greater flexion angles. The aim of this work is to make a comparative bidimensional study of the kinematic and dynamic variables of the excecution of the parallel squat exercise with the front and back bar. It is observed in the knee a better development of energy with the front bar, allowing a better muscular exercise with the same load. The mean power absorbed by the hip with the back bar is considerably greater, associated to the speed of the gesture.

  9. Stretch Band Exercise Program

    ERIC Educational Resources Information Center

    Skirka, Nicholas; Hume, Donald

    2007-01-01

    This article discusses how to use stretch bands for improving total body fitness and quality of life. A stretch band exercise program offers a versatile and inexpensive option to motivate participants to exercise. The authors suggest practical exercises that can be used in physical education to improve or maintain muscular strength and endurance,

  10. Advanced resistive exercise device

    NASA Technical Reports Server (NTRS)

    Raboin, Jasen L. (Inventor); Niebuhr, Jason (Inventor); Cruz, Santana F. (Inventor); Lamoreaux, Christopher D. (Inventor)

    2008-01-01

    The present invention relates to an exercise device, which includes a vacuum cylinder and a flywheel. The flywheel provides an inertial component to the load, which is particularly well suited for use in space as it simulates exercising under normal gravity conditions. Also, the present invention relates to an exercise device, which has a vacuum cylinder and a load adjusting armbase assembly.

  11. Stretch Band Exercise Program

    ERIC Educational Resources Information Center

    Skirka, Nicholas; Hume, Donald

    2007-01-01

    This article discusses how to use stretch bands for improving total body fitness and quality of life. A stretch band exercise program offers a versatile and inexpensive option to motivate participants to exercise. The authors suggest practical exercises that can be used in physical education to improve or maintain muscular strength and endurance,…

  12. Exercising in Cold Weather

    MedlinePLUS

    ... www.nia.nih.gov/Go4Life Exercising in Cold Weather Exercise has benefits all year, even during winter. ... activities when it’s cold outside: l Check the weather forecast. If it’s very windy or cold, exercise ...

  13. A Group Leadership Exercise.

    ERIC Educational Resources Information Center

    Meyer, John; Stafford, Jeff

    A group leadership exercise that incorporates the elements of leadership and other aspects of interaction within small groups can be useful in a basic communication course. The exercise is designed around three basic leadership styles: laissez-faire, democratic, and authoritarian. The exercise is conducted in the following way: (1) the class…

  14. Sleep, Exercise, and Nutrition.

    ERIC Educational Resources Information Center

    Harrelson, Orvis A.; And Others

    The first part of this booklet concerns why sleep and exercise are necessary. It includes a discussion of what occurs during sleep and what dreams are. It also deals with the benefits of exercise, fatigue, posture, and the correlation between exercise and personality. The second part concerns nutrition and the importance of food. This part covers…

  15. Exercise, Aging and Longevity.

    ERIC Educational Resources Information Center

    Brown, Stanley P.; Cundiff, David E.

    1988-01-01

    The question of whether or not a lifelong program of exercise actually has a bearing on longevity is discussed. The effects of exercise on the aging process, and the longevity-exercise relationship are reviewed. The conflicting evidence on the subject is presented. (JL)

  16. [Exercise and diabetes].

    PubMed

    Murillo García, Serafín; Novials Sardà, Anna

    2011-05-01

    The recommendations about physical exercise in people with diabetes have changed in parallel with the development of knowledge and treatments of the disease. Before the discovery of insulin, exercise was considered a dangerous activity, usually discouraged by the increased risk of ketosis that resulted. In contrast, today, exercise is a basic activity included within the recommended healthy lifestyle for patients with diabetes. PMID:21776934

  17. Chinese eye exercises.

    PubMed

    Roy, F H

    1980-01-01

    Eye exercises are regularly performed by the Chinese children in this highly regimented society. These exercises, based on acupuncture points, are used by children who are approximately 6 to 13 years of age. Chinese eye exercises are reported to be beneficial for myopia, a common Oriental ocular problem. I know of no scientific study that either proves or disproves this. PMID:7391914

  18. Exercise and Your Heart.

    ERIC Educational Resources Information Center

    National Heart and Lung Inst. (DHHS/NIH), Bethesda, MD.

    This pamphlet presents information on the effects of physical activity on the heart and practical guidelines for starting and staying on an exercise program. The following topics are discussed: (1) the benefits of getting sufficient exercise; (2) possible risks in exercising compared to benefits; (3) when to seek doctor's advice and prevention of…

  19. Acute Post-Exercise Myofibrillar Protein Synthesis Is Not Correlated with Resistance Training-Induced Muscle Hypertrophy in Young Men

    PubMed Central

    Mitchell, Cameron J.; Churchward-Venne, Tyler A.; Parise, Gianni; Bellamy, Leeann; Baker, Steven K.; Smith, Kenneth; Atherton, Philip J.; Phillips, Stuart M.

    2014-01-01

    Muscle hypertrophy following resistance training (RT) involves activation of myofibrillar protein synthesis (MPS) to expand the myofibrillar protein pool. The degree of hypertrophy following RT is, however, highly variable and thus we sought to determine the relationship between the acute activation of MPS and RT-induced hypertrophy. We measured MPS and signalling protein activation after the first session of resistance exercise (RE) in untrained men (n = 23) and then examined the relation between MPS with magnetic resonance image determined hypertrophy. To measure MPS, young men (24±1 yr; body mass index  = 26.4±0.9 kg•m2) underwent a primed constant infusion of L-[ring-13C6] phenylalanine to measure MPS at rest, and acutely following their first bout of RE prior to 16 wk of RT. Rates of MPS were increased 235±38% (P<0.001) above rest 60–180 min post-exercise and 184±28% (P = 0.037) 180–360 min post exercise. Quadriceps volume increased 7.9±1.6% (−1.9–24.7%) (P<0.001) after training. There was no correlation between changes in quadriceps muscle volume and acute rates of MPS measured over 1–3 h (r = 0.02), 3–6 h (r = 0.16) or the aggregate 1–6 h post-exercise period (r = 0.10). Hypertrophy after chronic RT was correlated (r = 0.42, P = 0.05) with phosphorylation of 4E-BP1Thr37/46 at 1 hour post RE. We conclude that acute measures of MPS following an initial exposure to RE in novices are not correlated with muscle hypertrophy following chronic RT. PMID:24586775

  20. Enhancing Facial Aesthetics with Muscle Retraining Exercises-A Review

    PubMed Central

    D’souza, Raina; Kini, Ashwini; D’souza, Henston; Shetty, Omkar

    2014-01-01

    Facial attractiveness plays a key role in social interaction. ‘Smile’ is not only a single category of facial behaviour, but also the emotion of frank joy which is expressed on the face by the combined contraction of the muscles involved. When a patient visits the dental clinic for aesthetic reasons, the dentist considers not only the chief complaint but also the overall harmony of the face. This article describes muscle retraining exercises to achieve control over facial movements and improve facial appearance which may be considered following any type of dental rehabilitation. Muscle conditioning, training and strengthening through daily exercises will help to counter balance the aging effects. PMID:25302289

  1. Enhancing facial aesthetics with muscle retraining exercises-a review.

    PubMed

    D'souza, Raina; Kini, Ashwini; D'souza, Henston; Shetty, Nitin; Shetty, Omkar

    2014-08-01

    Facial attractiveness plays a key role in social interaction. 'Smile' is not only a single category of facial behaviour, but also the emotion of frank joy which is expressed on the face by the combined contraction of the muscles involved. When a patient visits the dental clinic for aesthetic reasons, the dentist considers not only the chief complaint but also the overall harmony of the face. This article describes muscle retraining exercises to achieve control over facial movements and improve facial appearance which may be considered following any type of dental rehabilitation. Muscle conditioning, training and strengthening through daily exercises will help to counter balance the aging effects. PMID:25302289

  2. Muscle Adaptations Following Short-Duration Bed Rest with Integrated Resistance, Interval, and Aerobic Exercise

    NASA Technical Reports Server (NTRS)

    Hackney, Kyle J.; Scott, Jessica M.; Buxton, Roxanne; Redd-Goetchius, Elizabeth; Crowell, J. Brent; Everett, Meghan E.; Wickwire, Jason; Ryder, Jeffrey W.; Bloomberg, Jacob J.; Ploutz-Snyder, Lori L.

    2011-01-01

    Unloading of the musculoskeletal system during space flight results in deconditioning that may impair mission-related task performance in astronauts. Exercise countermeasures have been frequently tested during bed rest (BR) and limb suspension; however, high-intensity, short-duration exercise prescriptions have not been fully explored. PURPOSE: To determine if a high intensity resistance, interval, and aerobic exercise program could protect against muscle atrophy and dysfunction when performed during short duration BR. METHODS: Nine subjects (1 female, 8 male) performed a combination of supine exercises during 2 weeks of horizontal BR. Resistance exercise (3 d / wk) consisted of squat, leg press, hamstring curl, and heel raise exercises (3 sets, 12 repetitions). Aerobic (6 d / wk) sessions alternated continuous (75% VO2 peak) and interval exercise (30 s, 2 min, and 4 min) and were completed on a supine cycle ergometer and vertical treadmill, respectively. Muscle volumes of the upper leg were calculated pre, mid, and post-BR using magnetic resonance imaging. Maximal isometric force (MIF), rate of force development (RFD), and peak power of the lower body extensors were measured twice before BR (averaged to represent pre) and once post BR. ANOVA with repeated measures and a priori planned contrasts were used to test for differences. RESULTS: There were no changes to quadriceps, hamstring, and adductor muscle volumes at mid and post BR time points compared to pre BR (Table 1). Peak power increased significantly from 1614 +/- 372 W to 1739 +/- 359 W post BR (+7.7%, p = 0.035). Neither MIF (pre: 1676 +/- 320 N vs. post: 1711 +/- 250 N, +2.1%, p = 0.333) nor RFD (pre: 7534 +/- 1265 N/ms vs. post: 6951 +/- 1241 N/ms, -7.7%, p = 0.136) were significantly impaired post BR.

  3. Levels of Exercise

    MedlinePLUS

    ... common type of diabetes. It may even help you live longer. What is it? Aerobic activity gets your heart ... common type of diabetes. It may even help you live longer. » Muscle-strengthening activity What is it? Muscle-strengthening ...

  4. Exercise in neuromuscular diseases.

    PubMed

    Abresch, R Ted; Carter, Gregory T; Han, Jay J; McDonald, Craig M

    2012-08-01

    This article reviews the current knowledge regarding the benefits and contraindications of exercise on individuals with neuromuscular diseases (NMDs). Specific exercise prescriptions for individuals with NMDs do not exist because the evidence base is limited. Understanding the effect of exercise on individuals with NMDs requires the implementation of a series of multicenter, randomized controlled trials that are sufficiently powered and use reliable and valid outcome measures to assess the effect of exercise interventions-a major effort for each NMD. In addition to traditional measures of exercise efficacy, outcome variables should include measures of functional status and health-related quality of life. PMID:22938880

  5. Effectiveness of muscle strengthening and description of protocols for preventing falls in the elderly: a systematic review

    PubMed Central

    Ishigaki, Erika Y.; Ramos, Lidiane G.; Carvalho, Elisa S.; Lunardi, Adriana C.

    2014-01-01

    Background Falls are a geriatric syndrome that is considered a significant public health problem in terms of morbidity and mortality because they lead to a decline in functional capacity and an impaired quality of life in the elderly. Lower limb muscle strengthening seems to be an effective intervention for preventing falls; however, there is no consensus regarding the best method for increasing lower limb muscle strength. Objectives To analyze the effectiveness of lower limb muscle strengthening and to investigate and describe the protocols used for preventing falls in elderly subjects. Method We performed a systematic review of randomized and controlled clinical trials published between 2002 and 2012 in the databases PubMed, EMBASE, Scopus, Web of Science, and PEDro that cited some type of lower limb muscle strengthening protocol and that evaluated the incidence of falls as the primary outcome exclusively in elderly subjects. Twelve studies met the inclusion criteria. Qualitative analysis was performed by independent reviewers applying the PEDro scale. Results The data obtained from the selected studies showed lower fall rates in the intervention groups compared to controls. Six studies described the lower limb muscle strengthening protocol in detail. High methodological quality was found in 6 studies (PEDro score ≥7/10 points). Conclusions The methodological quality of the studies in this area appears to leave little doubt regarding the effectiveness of lower limb strengthening exercises for preventing falls in elderly subjects, however the interventions in these studies were poorly reported. PMID:24760166

  6. Effect of Therapeutic Exercise for Hip Osteoarthritis Pain: Results of a Meta-Analysis

    PubMed Central

    Hernández-Molina, Gabriela; Reichenbach, Stephan; Zhang, Bin; LaValley, Michael; Felson, David T.

    2009-01-01

    Objective Recommendations for lower extremity osteoarthritis (OA) and exercise have been primarily based on knee studies. To provide more targeted recommendations for the hip, we gathered evidence for the efficacy of exercise for hip OA from randomized controlled trials. Methods A bibliographic search identified trials that were randomized, controlled, completed by ≥60% of subjects, and involved an exercise group (strengthening and/or aerobic) versus a nonexercise control group for pain relief in hip OA. Two reviewers independently performed the data extraction and contacted the authors when necessary. Effect sizes (ES) of treatment versus control and the I2 statistic to assess heterogeneity across trials were calculated. Trial data were combined using a random-effects meta-analysis. Results Nine trials met the inclusion criteria (1,234 subjects), 7 of which combined hip and knee OA; therefore, we contacted the authors who provided the data on hip OA patients. In comparing exercise treatment versus control, we found a beneficial effect of exercise with an ES of −0.38 (95% confidence interval [95% CI] −0.68, −0.08; P = 0.01), but with high heterogeneity (I2 = 75%) among trials. Heterogeneity was caused by 1 trial consisting of an exercise intervention that was not administered in person. Removing this study left 8 trials (n = 493) with similar exercise strategy (specialized hands-on exercise training, all of which included at least some element of muscle strengthening), and demonstrated exercise benefit with an ES of −0.46 (95% CI −0.64, −0.28; P < 0.0001). Conclusion Therapeutic exercise, especially with an element of strengthening, is an efficacious treatment for hip OA. PMID:18759315

  7. Exercise and the microbiota

    PubMed Central

    O’Sullivan, Orla; Cronin, Owen; Clarke, Siobhan F; Murphy, Eileen F; Molloy, Micheal G; Shanahan, Fergus; Cotter, Paul D

    2015-01-01

    Sedentary lifestyle is linked with poor health, most commonly obesity and associated disorders, the corollary being that exercise offers a preventive strategy. However, the scope of exercise biology extends well beyond energy expenditure and has emerged as a great ‘polypill’, which is safe, reliable and cost-effective not only in disease prevention but also treatment. Biological mechanisms by which exercise influences homeostasis are becoming clearer and involve multi-organ systemic adaptations. Most of the elements of a modern lifestyle influence the indigenous microbiota but few studies have explored the effect of increased physical activity. While dietary responses to exercise obscure the influence of exercise alone on gut microbiota, professional athletes operating at the extremes of performance provide informative data. We assessed the relationship between extreme levels of exercise, associated dietary habits and gut microbiota composition, and discuss potential mechanisms by which exercise may exert a direct or indirect influence on gut microbiota. PMID:25800089

  8. Practical Approaches to Prescribing Physical Activity and Monitoring Exercise Intensity.

    PubMed

    Reed, Jennifer L; Pipe, Andrew L

    2016-04-01

    Regular physical activity helps to prevent heart disease, and reduces the risk of first or subsequent cardiovascular events. It is recommended that Canadian adults accumulate at least 150 minutes of moderate- to vigorous-intensity aerobic exercise per week, in bouts of 10 minutes or more, and perform muscle- and bone-strengthening activities at least 2 days per week. Individual exercise prescriptions can be developed using the frequency, intensity, time, and type principles. Increasing evidence suggests that high-intensity interval training is efficacious for a broad spectrum of heart health outcomes. Several practical approaches to prescribing and monitoring exercise intensity exist including: heart rate monitoring, the Borg rating of perceived exertion scale, the Talk Test, and, motion sensors. The Borg rating of perceived exertion scale matches a numerical value to an individual's perception of effort, and can also be used to estimate heart rate. The Talk Test, the level at which simple conversation is possible, can be used to monitor desired levels of moderate- to vigorous-intensity exercise. Motion sensors can provide users with practical and useful exercise training information to aid in meeting current exercise recommendations. These approaches can be used by the public, exercise scientists, and clinicians to easily and effectively guide physical activity in a variety of settings. PMID:26897182

  9. Physiotherapeutic scoliosis-specific exercises for adolescents with idiopathic scoliosis.

    PubMed

    Bettany-Saltikov, J; Parent, E; Romano, M; Villagrasa, M; Negrini, S

    2014-02-01

    The use of exercises for the treatment of Adolescents with Idiopathic Scoliosis is controversial. Whilst exercises are routinely used in a number of central and southern European countries, most centres in the rest of the world (mainly in Anglo-Saxon countries), do not advocate its use. One of the reasons for this is that many health care professionals are usually not conversant with the differences between generalised physiotherapy exercises and physiotherapeutic scoliosis-specific exercises (PSSE): while the former are generic exercises usually consisting of low-impact stretching and strengthening activities like yoga, Pilates and the Alexander technique, PSSE consist of a program of curve-specific exercise protocols which are individually adapted to a patients' curve site, magnitude and clinical characteristics. PSSEs are performed with the therapeutic aim of reducing the deformity and preventing its progression. It also aims to stabilise the improvements achieved with the ultimate goal of limiting the need for corrective braces or the necessity of surgery. This paper introduces the different 'Schools' and approaches of PSSE currently practiced (Scientific Exercise Approach to Scoliosis - SEAS, Schroth, Barcelona Scoliosis Physical Therapy School - BSPTS, Dobomed, Side Shift, Functional Individual Therapy of Scoliosis - FITS and Lyon) and discusses their commonalities and differences. PMID:24525556

  10. Capacity strengthening for environmental assessment in Benin.

    PubMed

    Adohinzin, Junior Bloh Nignilo; Xu, Ling; Du, Jing; Yang, Fenglin

    2011-09-01

    For over three decades, environmental assessment (EA) has gained increasing international recognition as a means of ensuring sustainable development. In light of environmental challenges, Benin has endorsed the principle that a healthy environment is a human right. This concern is manifested by the creation of many institutions for managing environmental issues. But until today, environmental problems are still on the rise and getting worse day by day because of Benin's limited experience in the field of EA. If EA is to be perceived as an instrument of sustainable development, it is important to take into account the achievements and the needs of the country in this field; because we cannot respond properly and adequately in the field of capacity strengthening in EA without first be familiar with what exists, what is fact, and what is needed. In this study, we address and analyze the status of existing resources in the field of EA in Benin with the purpose of identifying the needs for capacity strengthening to enhance environmental assessment effectiveness in the country. The detailed presentation of the results shows that the legislative and institutional resources are available and represent a strong element in the system of environmental management in Benin. However, there is still a room for improvements towards environmental governance before it becomes a solid system of decision supporting all sectors of intervention because the effective application of those laws and texts still constitute big challenges. Below are the main reasons that explain the particular situation: majority of the laws are put in force very late or taken without implementing decree at all; the organizational capabilities have large gaps; the absence of a mechanism for evaluating the needs for strengthening capacity for EA. Recommendations pinpointed three types of needs which must be filled to enhance the effectiveness of EA in Benin: upstream needs of the structure of EA; implementation and enforcement needs; and, maintenance and efficiency needs. PMID:21136291

  11. Bullialdus - Strengthening the case for lunar plutons

    NASA Technical Reports Server (NTRS)

    Pieters, Carle M.

    1991-01-01

    Although many craters expose materials of a composition different from that of the local surroundings, Bullialdus has excavated material representing three distinct stratigraphic zones that occur in the upper 6 km of crust, the top two of which are gabbroic and the deepest of which is noritic. This three-component stratigraphy at Bullialdus provides strong evidence that the lunar crust includes pockets of compositionally layered material reminiscent of mafic layered plutons. When combined with previous information on the compositional diversity at other large craters, these remote analyses obtained in a geologic context substantially strengthen the hypothesis suggested from lunar samples that plutons play an integral role in lunar crustal evolution.

  12. Computer simulation of concentrated solid solution strengthening

    NASA Technical Reports Server (NTRS)

    Kuo, C. T. K.; Arsenault, R. J.

    1976-01-01

    The interaction forces between a straight edge dislocation moving through a three-dimensional block containing a random array of solute atoms were determined. The yield stress at 0 K was obtained by determining the average maximum solute-dislocation interaction force that is encountered by edge dislocation, and an expression relating the yield stress to the length of the dislocation and the solute concentration is provided. The magnitude of the solid solution strengthening due to solute atoms can be determined directly from the numerical results, provided the dislocation line length that moves as a unit is specified.

  13. Effects of High-Intensity Blood Flow Restriction Exercise on Muscle Fatigue

    PubMed Central

    Neto, Gabriel R.; Santos, Heleodório H.; Sousa, Juliana B. C.; Júnior, Adenilson T. A.; Araújo, Joamira P.; Aniceto, Rodrigo R.; Sousa, Maria S. C.

    2014-01-01

    Strength training combined with blood flow restriction (BFR) have been used to improve the levels of muscle adaptation. The aim of this paper was to investigate the acute effect of high intensity squats with and without blood flow restriction on muscular fatigue levels. Twelve athletes (aged 25.95 ± 0.84 years) were randomized into two groups: without Blood Flow Restriction (NFR, n = 6) and With Blood Flow Restriction (WFR, n = 6) that performed a series of free weight squats with 80% 1-RM until concentric failure. The strength of the quadriceps extensors was assessed in a maximum voluntary isometric contraction integrated to signals from the surface electromyogram. The average frequency showed significant reductions in the WFR group for the vastus lateralis and vastus medialis muscles, and intergroup only for the vastus medialis. In conclusion, a set of squats at high intensity with BFR could compromise muscle strength immediately after exercise, however, differences were not significant between groups. PMID:25114743

  14. Strengthening And stretching for Rheumatoid Arthritis of the Hand (SARAH). A randomised controlled trial and economic evaluation.

    PubMed Central

    Williams, Mark A; Williamson, Esther M; Heine, Peter J; Nichols, Vivien; Glover, Matthew J; Dritsaki, Melina; Adams, Jo; Dosanjh, Sukhdeep; Underwood, Martin; Rahman, Anisur; McConkey, Christopher; Lord, Joanne; Lamb, Sarah E

    2015-01-01

    BACKGROUND The effectiveness of exercise for improving hand and wrist function in people with rheumatoid arthritis (RA) is uncertain. OBJECTIVES The study aims were (1) to estimate the clinical effectiveness and cost-effectiveness of adding an optimised exercise programme for hands and upper limbs to standard care for patients with RA; and (2) to qualitatively describe the experience of participants in the trial with a particular emphasis on acceptability of the intervention, exercise behaviours and reasons for adherence/non-adherence. DESIGN A pragmatic, multicentred, individually randomised controlled trial with an embedded qualitative study. Outcome assessors were blind to group assignment and independent of treatment delivery. SETTING Seventeen NHS trusts in England comprising 21 rheumatology and therapy departments. PARTICIPANTS Adults with RA who had pain and dysfunction of the hands and/or wrists and had been on stable medication for at least 3 months. Patients were excluded if they were under 18 years old, had undergone upper limb surgery/fracture in the last 6 months, were on a waiting list for upper limb surgery or were pregnant. INTERVENTIONS Usual care or usual care plus an individualised exercise programme. Usual care consisted of joint protection education, general exercise advice and functional splinting if required. The exercise programme consisted of six sessions of strengthening and stretching exercises with a hand therapist, daily home exercises and strategies to maximise adherence. MAIN OUTCOME MEASURES The primary outcome was the Michigan Hand Outcome Questionnaire (MHQ) overall hand function subscale score at 12 months. Secondary outcome measures included the full MHQ, pain, health-related quality of life (Short Form questionnaire-12 items), impairment (grip strength, dexterity and range of motion) and self-efficacy. European Quality of Life-5 Dimensions, medication and health-care use were collected for the health economics evaluation. Follow-up was at 4 and 12 months post randomisation. Analysis was performed on an intention-to-treat basis. RESULTS We randomised 490 patients (244 to usual care, 246 to exercise programme). Compliance with the treatments was very good (93% of usual care participants and 75% of exercise programme participants completed treatment). Outcomes were obtained for 89% of participants at 12 months (222 for usual care, 216 for exercise programme). There was a statistically significant difference in favour of the exercise programme for the primary outcome at 4 and 12 months [mean difference 4.6 points, 95% confidence interval (CI) 2.2 to 7.0 points; and mean difference 4.4 points, 95% CI 1.6 to 7.1 points, respectively]. There were no significant differences in pain scores or adverse events. The estimated difference in mean quality-adjusted life-years (QALYs) accrued over 12 months was 0.01 greater (95% CI -0.03 to 0.05) in the exercise programme group. Imputed analysis produced incremental cost-effectiveness ratio estimates of £17,941 (0.59 probability of cost-effectiveness at willingness-to-pay threshold of £30,000 per QALY). The qualitative study found the exercise programme to be acceptable and highlighted the importance of the therapist in enabling patients to establish a routine and incorporate the exercises into their lives. CONCLUSIONS The results of the Strengthening And stretching for Rheumatoid Arthritis of the Hand trial suggest that the addition of an exercise programme for RA hands/wrists to usual care is clinically effective and cost-effective when compared with usual care alone. No adverse effects were associated with the exercise programme. The economic analysis suggests that the intervention is likely to be cost-effective. STUDY REGISTRATION Current Controlled Trials ISRCTN 89936343. PMID:25748549

  15. The relationship between exercise work intervals and duration of exercise on lower extremity training induced by electrical stimulation in humans with spinal cord injuries.

    PubMed

    Petrofsky, J S; Stacy, R; Laymon, M

    2000-08-01

    A group of 90 male paraplegics were studied to determine the optimal training protocol for isokinetic exercise induced by functional electrical stimulation of the quadriceps muscles. The parameters that were varied were the number of training sessions a week, the length of the training sessions each day, and the work-rest intervals in each training session. Training for 3 days a week for 30 min a day with 6 s of exercise and 6 s of rest proved the optimal protocol. Training for 5 days or for 1 day a week was not as effective in training strength or endurance. A combination of 50% work and 50% rest produced a much greater gain in strength and endurance than work:rest ratios of 66%:33% or 25%:75%. When training was conducted for 5 min, 15 min or 30 min each day, the greatest increase was found when the muscles were exercised for 30 min each day. While more variables need to be examined, this study has provided some initial guidelines for isokinetic training of humans using electrical stimulation. PMID:10985608

  16. Molecular profiles of Quadriceps muscle in myostatin-null mice reveal PI3K and apoptotic pathways as myostatin targets

    PubMed Central

    Chelh, Ilham; Meunier, Bruno; Picard, Brigitte; Reecy, Mark James; Chevalier, Catherine; Hocquette, Jean-François; Cassar-Malek, Isabelle

    2009-01-01

    Background Myostatin (MSTN), a member of the TGF-β superfamily, has been identified as a negative regulator of skeletal muscle mass. Inactivating mutations in the MSTN gene are responsible for the development of a hypermuscular phenotype. In this study, we performed transcriptomic and proteomic analyses to detect altered expression/abundance of genes and proteins. These differentially expressed genes and proteins may represent new molecular targets of MSTN and could be involved in the regulation of skeletal muscle mass. Results Transcriptomic analysis of the Quadriceps muscles of 5-week-old MSTN-null mice (n = 4) and their controls (n = 4) was carried out using microarray (human and murine oligonucleotide sequences) of 6,473 genes expressed in muscle. Proteomic profiles were analysed using two-dimensional gel electrophoresis coupled with mass spectrometry. Comparison of the transcriptomic profiles revealed 192 up- and 245 down- regulated genes. Genes involved in the PI3K pathway, insulin/IGF pathway, carbohydrate metabolism and apoptosis regulation were up-regulated. Genes belonging to canonical Wnt, calcium signalling pathways and cytokine-receptor cytokine interaction were down-regulated. Comparison of the protein profiles revealed 20 up- and 18 down-regulated proteins spots. Knockout of the MSTN gene was associated with up-regulation of proteins involved in glycolytic shift of the muscles and down-regulation of proteins involved in oxidative energy metabolism. In addition, an increased abundance of survival/anti-apoptotic factors were observed. Conclusion All together, these results showed a differential expression of genes and proteins related to the muscle energy metabolism and cell survival/anti-apoptotic pathway (e.g. DJ-1, PINK1, 14-3-3ε protein, TCTP/GSK-3β). They revealed the PI3K and apoptotic pathways as MSTN targets and are in favour of a role of MSTN as a modulator of cell survival in vivo. PMID:19397818

  17. RECONSTRUCTION OF THE ANTERIOR CRUCIATE LIGAMENT WITH THE CENTRAL THIRD OF THE QUADRICEPS MUSCLE TENDON: ANALYSIS OF 10-YEAR RESULTS

    PubMed Central

    Guimarães, Marcus Valladares; Junior, Lúcio Honório de Carvalho; Terra, Dalton Lopes

    2015-01-01

    Objective: Assess clinical results using two different protocols, 10 years after ACL reconstruction surgery with the central third of quadriceps muscle tendon (QT). Method: Between November /1997 and April/1998, 25 patients were submitted to 25 ACL reconstructions with QT by transtibial technique. The bone portion of the graft was fixated on femoral tunnel with interference screw and the tendinous portion of tibial tunnel with screw with washer. Two patients injured the new when playing soccer. Six patients were not available for follow-up (24%). Seventeen patients were evaluated, 15 men and two women, with mean age at surgery time of 28.53 ± 6.64 years. All patients were examined at six months, one year, and ten years after surgery. Clinical evaluation was made by the Lysholm scale, and the knee evaluation, with the Hospital for Special Surgery scale. Results: The patients had their injuries operated after 9.87 ± 14.42 months of the accident. According to Lysholm scale, the results at the end of the first year were 98.71 ± 2.47 and, after 10 years, 97.35 ± 3.12. Using the Hospital for Special Surgery scale, the mean score was 95.07 ± 5.23 in one year, and 94.87 ± 4.16 in 10 years. All patients returned to their professional activities with the same previous status. Fifteen (88.24%) patients were able to return to their sports activities, one by modifying the practice, while another one switched to another sport. No patient complained of pain on the donor area in the medium and long term. The sports return rate was excellent, and no changes were found on the femoropatellar joint. PMID:27022511

  18. Roller-Massager Application to the Quadriceps and Knee-Joint Range of Motion and Neuromuscular Efficiency During a Lunge

    PubMed Central

    Bradbury-Squires, David J.; Noftall, Jennifer C.; Sullivan, Kathleen M.; Behm, David G.; Power, Kevin E.; Button, Duane C.

    2015-01-01

    Context: Roller massagers are used as a recovery and rehabilitative tool to initiate muscle relaxation and improve range of motion (ROM) and muscular performance. However, research demonstrating such effects is lacking. Objective: To determine the effects of applying a roller massager for 20 and 60 seconds on knee-joint ROM and dynamic muscular performance. Design: Randomized controlled clinical trial. Setting: University laboratory. Patients or Other Participants: Ten recreationally active men (age = 26.6 ± 5.2 years, height = 175.3 ± 4.3 cm, mass = 84.4 ± 8.8 kg). Intervention(s): Participants performed 3 randomized experimental conditions separated by 24 to 48 hours. In condition 1 (5 repetitions of 20 seconds) and condition 2 (5 repetitions of 60 seconds), they applied a roller massager to the quadriceps muscles. Condition 3 served as a control condition in which participants sat quietly. Main Outcome Measure(s): Visual analog pain scale, electromyography (EMG) of the vastus lateralis (VL) and biceps femoris during roller massage and lunge, and knee-joint ROM. Results: We found no differences in pain between the 20-second and 60-second roller-massager conditions. During 60 seconds of roller massage, pain was 13.5% (5.7 ± 0.70) and 20.6% (6.2 ± 0.70) greater at 40 seconds and 60 seconds, respectively, than at 20 seconds (P < .05). During roller massage, VL and biceps femoris root mean square (RMS) EMG was 8% and 7%, respectively, of RMS EMG recorded during maximal voluntary isometric contraction. Knee-joint ROM was 10% and 16% greater in the 20-second and 60-second roller-massager conditions, respectively, than the control condition (P < .05). Finally, average lunge VL RMS EMG decreased as roller-massage time increased (P < .05). Conclusions: Roller massage was painful and induced muscle activity, but it increased knee-joint ROM and neuromuscular efficiency during a lunge. PMID:25415414

  19. THE ECONOMICS OF INTENSE EXERCISE

    PubMed Central

    Meltzer, David O.; Jena, Anupam B.

    2010-01-01

    Despite the well-known benefits of exercise, the time required for exercise is widely understood as a major reason for low levels of exercise in the US. Intensity of exercise can change the time required for a given amount of total exercise but has never been studied from an economic perspective. We present a simple model of exercise behavior which suggests that the intensity of exercise should increase relative to time spent exercising as wages increase, holding other determinants of exercise constant. Our empirical results identify an association between income and exercise intensity that is consistent with the hypothesis that people respond to increased time costs of exercise by increasing intensity. More generally, our results suggest that time costs may be an important determinant of exercise patterns and that factors that can influence the time costs of exercise, such as intensity, may be important concerns in designing interventions to promote exercise. PMID:20371127

  20. Effect of evidence-based trunk stability exercises on the thickness of the trunk muscles

    PubMed Central

    Yang, Hoe-song; Lee, Yeon-seop; Jin, Sun-ae

    2015-01-01

    [Purpose] This study was conducted to investigate the effect of four spine stability exercises on the thickness of the internal and external oblique abdominal muscles, the transverses abdominis, and the multifidus muscles. [Subjects and Methods] Forty healthy adults were enrolled and randomly allocated to four groups. Ten participants performed bridge exercises (BE) while lying on their back; 10 others performed the same exercises with their right legs up (BERL); another 10 performed the same exercises on their side (SBE); and the remaining 10 performed them in a quadruped position with left arm and right leg lifts (QLARL). The participants performed the exercises three times a week for five weeks. The thicknesses of the muscles before and after the interventions were measured using ultrasound. [Results] The results show that the normal bridge exercise significantly thickened the TrA; BERL, the LM; QLARL, the IO; and SBE, the EO and the IO. [Conclusion] All four spine stability exercises were effective. The normal bridge exercise and BERL selectively strengthened the local muscles at the early stage of the treatment. We consider SBE and QLARL should be used in the later stages of treatments because they strengthen both the local and global muscles. PMID:25729194

  1. Trigger Point Dry Needling and Proprioceptive Exercises for the Management of Chronic Ankle Instability: A Randomized Clinical Trial.

    PubMed

    Salom-Moreno, Jaime; Ayuso-Casado, Blanca; Tamaral-Costa, Beatriz; Sánchez-Milá, Zacarías; Fernández-de-Las-Peñas, César; Alburquerque-Sendín, Francisco

    2015-01-01

    Objective. To compare the effects of combined trigger point dry needling (TrP-DN) and proprioceptive/strengthening exercises to proprioceptive/strengthening exercises on pain and function in ankle instability. Methods. Twenty-seven (44% female, mean age: 33 ± 3 years) individuals with unilateral ankle instability were randomly assigned to an experimental group who received proprioceptive/strengthening exercises combined with TrP-DN into the lateral peroneus muscle and a comparison group receiving the same proprioceptive/strengthening exercise program alone. Outcome included function assessed with the Foot and Ankle Ability Measure (FAAM) and ankle pain intensity assessed with a numerical pain rate scale (NPRS). They were captured at baseline and 1-month follow-up after the intervention. Results. The ANOVAs found significant Group ∗ Time Interactions for both subscales of the FAAM (ADL: F = 8.211; P = 0.008; SPORTS: F = 13.943; P < 0.001) and for pain (F = 44.420; P < 0.001): patients receiving TrP-DN plus proprioceptive/strengthening exercises experienced greater improvements in function and pain than those receiving the exercise program alone. Between-groups effect sizes were large in all outcomes (SMD > 2.1) in favor of the TrP-DN group. Conclusions. This study provides evidence that the inclusion of TrP-DN within the lateral peroneus muscle into a proprioceptive/strengthening exercise program resulted in better outcomes in pain and function 1 month after the therapy in ankle instability. PMID:26064172

  2. Trigger Point Dry Needling and Proprioceptive Exercises for the Management of Chronic Ankle Instability: A Randomized Clinical Trial

    PubMed Central

    Salom-Moreno, Jaime; Ayuso-Casado, Blanca; Tamaral-Costa, Beatriz; Sánchez-Milá, Zacarías; Fernández-de-las-Peñas, César; Alburquerque-Sendín, Francisco

    2015-01-01

    Objective. To compare the effects of combined trigger point dry needling (TrP-DN) and proprioceptive/strengthening exercises to proprioceptive/strengthening exercises on pain and function in ankle instability. Methods. Twenty-seven (44% female, mean age: 33 ± 3 years) individuals with unilateral ankle instability were randomly assigned to an experimental group who received proprioceptive/strengthening exercises combined with TrP-DN into the lateral peroneus muscle and a comparison group receiving the same proprioceptive/strengthening exercise program alone. Outcome included function assessed with the Foot and Ankle Ability Measure (FAAM) and ankle pain intensity assessed with a numerical pain rate scale (NPRS). They were captured at baseline and 1-month follow-up after the intervention. Results. The ANOVAs found significant Group ∗ Time Interactions for both subscales of the FAAM (ADL: F = 8.211; P = 0.008; SPORTS: F = 13.943; P < 0.001) and for pain (F = 44.420; P < 0.001): patients receiving TrP-DN plus proprioceptive/strengthening exercises experienced greater improvements in function and pain than those receiving the exercise program alone. Between-groups effect sizes were large in all outcomes (SMD > 2.1) in favor of the TrP-DN group. Conclusions. This study provides evidence that the inclusion of TrP-DN within the lateral peroneus muscle into a proprioceptive/strengthening exercise program resulted in better outcomes in pain and function 1 month after the therapy in ankle instability. PMID:26064172

  3. Strengthening the Canadian alcohol advertising regulatory system.

    PubMed

    Heung, Carly M; Rempel, Benjamin; Krank, Marvin

    2012-01-01

    Research evidence points to harmful effects from alcohol advertising among children and youth. In particular, exposure to alcohol advertising has been associated with adolescents drinking both earlier and heavier. Although current federal and provincial guidelines have addressed advertising practices to prevent underage drinking, practice has not been supported by existing policy. While protective measures such as social marketing campaigns have the potential for counteracting the effects from alcohol advertising, the effectiveness of such measures can be easily drowned out with increasing advertising activities from the alcohol industry, especially without effective regulation. Research reviewed by the European Focus on Alcohol Safe Environment (FASE) Project has identified a set of key elements that are necessary to make alcohol advertising policy measures effective at protecting children and youth from the harmful effects of alcohol marketing. Using these key elements as an evaluation framework, there are critical components in the Canadian alcohol advertising regulatory system that clearly require strengthening. To protect impressionable children and youth against the harmful effects of alcohol advertising, 13 recommendations to strengthen current alcohol advertising regulations in Canada are provided for Canadian policy-makers, advertising standard agencies, and public health groups. PMID:23618638

  4. Carboxymethylated glucomannan as paper strengthening agent.

    PubMed

    Wang, Meng; He, Weitao; Wang, Shun; Song, Xianliang

    2015-07-10

    Strength additives play an important role in allowing the papermaking industry to achieve its objectives. In this study, a new kind of paper strengthening agent based on glucomannan was developed by treating it with sodium chloroacetate under alkaline conditions, and the effects on paper properties were evaluated. Results indicated that carboxymethylated glucomannan could significantly improve the paper properties. Compared to the untreated paper, the density, burst index, tensile index, and folding endurance were increased by 15.2%, 22.8%, 34.6%, 179.0%, respectively, when 0.9% carboxymethylated glucomannan was used. Polyamide-epichlorohydrin (PAE) was used to improve the wet strength of the paper. When 0.6% PAE and 0.6% carboxymethylated glucomannan were used, the burst index, dry tensile index, wet tensile index of paper were increased by 14.1%, 25%, 34.3%, respectively, as compared to that of the control, while the folding endurance decreased slightly. In addition, dry tensile index and wet tensile index were increased with increasing the carboxymethylation time of glucomannan. The results demonstrated that PAE and carboxymethylated glucomannan displayed a synergistic effect. SEM analysis illustrated that paper strengthening agent could increase the combination of fibers in paper. PMID:25857990

  5. Strengthening under Load: Experimental and Numerical Research

    NASA Astrophysics Data System (ADS)

    Vild, M.; Bajer, M.

    2015-11-01

    The paper presents experimental and numerical research of strengthening of columns under load using welded plates. Three sets of three columns each were tested. All columns were 3 m long. The load from loading cylinders was transmitted through knife-edge bearings, which ensured pinned boundary condition perpendicular to the weaker axis. Set (A) comprised columns with welded T shaped cross-section. Set (B) comprised columns with welded monosymmetric I shaped cross-section. Both sets (A) and (B) had been loaded monotonically until collapse occurred. Set (C) contained columns with T shaped cross-section with the same dimensions as the columns in set (A). The columns from set (C) were first loaded to 70 kN. The force was being held constant and the second flange was being welded to the web under load. After the welding process was finished and the specimen cooled, the column was loaded to failure. The average forces at collapse of column sets (A), (B) and (C) were 143 kN, 308 kN and 323 kN, respectively. It was unexpected that the columns strengthened under load (C) had higher average resistance than the columns welded without preload (B). It could be caused by the residual stress and distortion caused by welding. The study includes the results of finite element models of the problem created in ANSYS software. The results from the experiments and numerical simulations were compared.

  6. Articulating Support for Horizontal Resistive Exercise

    NASA Technical Reports Server (NTRS)

    Gundo, Daniel; Schaffner, Grant; Bentley, Jason; Loehr, James A.

    2005-01-01

    A versatile mechanical device provides support for a user engaged in any of a variety of resistive exercises in a substantially horizontal orientation. The unique features and versatility of the device promise to be useful in bedrest studies, rehabilitation, and specialized strength training. The device affords a capability for selectively loading and unloading of portions of the user s body through its support mechanisms, so that specific parts of the body can be trained with little or no effect on other parts that may be disabled or in the process of recovery from injury. Thus, the device is ideal for rehabilitation exercise programs prescribed by physicians and physical therapists. The capability for selective loading and support also offers potential benefits to strength and conditioning trainers and athletes who wish to selectively strengthen selected parts. The principal innovative aspect of the device is that it supports the subject s weight while enabling the subject, lying substantially horizontally, to perform an exercise that closely approximates a full standing squat. The device includes mechanisms that support the subject in such a way that the hips are free to translate both horizontally and vertically and are free to rotate about the line connecting the hips. At the same time, the shoulders are free to translate horizontally while the upper back is free to rotate about the line connecting the shoulders. Among the mechanisms for hip motion and support is a counterbalance that offsets the weight of the subject as the subject s pelvis translates horizontally and vertically and rotates the pelvis about the line connecting the hips. The counterbalance is connected to a pelvic support system that allows these pelvic movements. The subject is also supported at the shoulder by a mechanism that can tilt to provide continuous support of the upper back while allowing the rotation required for arching the back as the pelvis is displaced. The shoulder support also affords a capability for horizontal motion, and acts as the point of attachment of a load that is provided for squat and heel-raise exercises. The device is compatible with any resistive-exercise machine that provides bilateral loading via a moving cable or other mechanical linkage. The hip-translation and shoulder-translation and -rotation degrees of freedom of the supports can be locked individually or in combination in order to support the subject as necessary for exercises other than the standing squat. If necessary, for such exercises, the load can be applied directly to the subject by use of various attachments. In addition to the aforementioned heel raise, such exercises include the upright row, leg press, curls, extension of the triceps, front raise, lateral raise, and rear raise.

  7. Writing Strengthens Orthography and Alphabetic-Coding Strengthens Phonology in Learning to Read Chinese

    ERIC Educational Resources Information Center

    Guan, Connie Qun; Liu, Ying; Chan, Derek Ho Leung; Ye, Feifei; Perfetti, Charles A.

    2011-01-01

    Learning to write words may strengthen orthographic representations and thus support word-specific recognition processes. This hypothesis applies especially to Chinese because its writing system encourages character-specific recognition that depends on accurate representation of orthographic form. We report 2 studies that test this hypothesis in…

  8. Writing Strengthens Orthography and Alphabetic-Coding Strengthens Phonology in Learning to Read Chinese

    ERIC Educational Resources Information Center

    Guan, Connie Qun; Liu, Ying; Chan, Derek Ho Leung; Ye, Feifei; Perfetti, Charles A.

    2011-01-01

    Learning to write words may strengthen orthographic representations and thus support word-specific recognition processes. This hypothesis applies especially to Chinese because its writing system encourages character-specific recognition that depends on accurate representation of orthographic form. We report 2 studies that test this hypothesis in

  9. Partial neuromuscular blockade and cardiovascular responses to static exercise in man.

    PubMed Central

    Leonard, B; Mitchell, J H; Mizuno, M; Rube, N; Saltin, B; Secher, N H

    1985-01-01

    In human subjects sustained static contractions of the quadriceps femoris in one leg were performed with the same absolute and the same relative intensity before and after partial neuromuscular blockade with either decamethonium or tubocurarine which reduced strength to about 50% of the control value. During the contractions performed with the same absolute force, the magnitude of the cardiovascular responses (heart rate and blood pressure) was greater during neuromuscular blockade than during control contractions. During the contractions involving the same relative force the magnitude of the cardiovascular responses was almost the same with and without neuromuscular blockade. These findings were independent of the drug used. The metabolic part of the exercise pressor reflex was assessed by the application of an arterial cuff 1/2 min before cessation of exercise and for the following 3 min of rest. Although heart rate and blood pressure decreased after cessation of exercise, application of the tourniquet resulted in higher post-exercise values and this effect was seen both with and without neuromuscular blockade. Muscle biopsies from the subjects' m. vastus lateralis were analysed for fast- and slow-twitch fibre composition showing 27-66% slow-twitch fibres. No correlation was found between cardiovascular responses to static exercise, with or without neuromuscular blockade, and fibre type predominance. The results suggest that the involvement of fast- or slow-twitch muscle fibres does not play a dominant role in the cardiovascular responses to static exercise in man. Both central command and reflex neural mechanisms are of importance, and it appears that these two control mechanisms are redundant and that neural occlusion may be operative. However, when partial neuromuscular blockade induces a disproportion between an increase in central command and a constant or decreasing muscle tension and metabolism, the larger signal arising from central command determines the magnitude of the cardiovascular responses. PMID:3999043

  10. Sex-specific influence of aging on exercising leg blood flow.

    PubMed

    Parker, Beth A; Smithmyer, Sandra L; Pelberg, Justin A; Mishkin, Aaron D; Proctor, David N

    2008-03-01

    Our previous work suggests that healthy human aging is associated with sex-specific differences in leg vascular responses during large muscle mass exercise (2-legged cycling) (Proctor DN, Parker BA. Microcirculation 13: 315-327, 2006). The present study determined whether age x sex interactions in exercising leg hemodynamics persist during small muscle mass exercise that is not limited by cardiac output. Thirty-one young (20-30 yr; 15 men/16 women) and 31 older (60-79 yr; 13 men/18 women) healthy, normally active adults performed graded single-leg knee extensions to maximal exertion. Femoral artery blood velocity and diameter (Doppler ultrasound), heart rate (ECG), and beat-to-beat arterial blood pressure (mean arterial pressure, radial artery tonometry) were measured during each 3-min work rate (4.8 and 8 W/stage for women and men, respectively). The results (means +/- SE) were as follows. Despite reduced resting leg blood flow and vascular conductance, older men exhibited relatively preserved exercising leg hemodynamic responses. Older women, by contrast, exhibited attenuated hyperemic (young: 52 +/- 3 ml.min(-1).W(-1); vs. older: 40 +/- 4 ml.min(-1).W(-1); P = 0.02) and vasodilatory responses (young: 0.56 +/- 0.06 ml.min(-1).mmHg(-1).W(-1) vs. older: 0.37 +/- 0.04 ml.min(-1).mmHg(-1) W(-1); P < 0.01) to exercise compared with young women. Relative (percentage of maximal) work rate comparisons of all groups combined also revealed attenuated vasodilator responses in older women (P < 0.01 for age x sex x work rate interaction). These sex-specific age differences were not abolished by consideration of hemoglobin, quadriceps muscle, muscle recruitment, and mechanical influences on muscle perfusion. Collectively, these findings suggest that local factors contribute to the sex-specific effects of aging on exercising leg hemodynamics in healthy adults. PMID:18162481

  11. Myoglobin O2 desaturation during exercise. Evidence of limited O2 transport.

    PubMed Central

    Richardson, R S; Noyszewski, E A; Kendrick, K F; Leigh, J S; Wagner, P D

    1995-01-01

    The assumption that cellular oxygen pressure (PO2) is close to zero in maximally exercising muscle is essential for the hypothesis that O2 transport between blood and mitochondria has a finite conductance that determines maximum O2 consumption. The unique combination of isolated human quadriceps exercise, direct measures of arterial, femoral venous PO2, and 1H nuclear magnetic resonance spectroscopy to detect myoglobin desaturation enabled this assumption to be tested in six trained men while breathing room air (normoxic, N) and 12% O2 (hypoxic, H). Within 20 s of exercise onset partial myoglobin desaturation was evident even at 50% of maximum O2 consumption, was significantly greater in H than N, and was then constant at an average of 51 +/- 3% (N) and 60 +/- 3% (H) throughout the incremental exercise protocol to maximum work rate. Assuming a myoglobin PO2 where 50% of myoglobin binding sites are bound with O2 of 3.2 mmHg, myoglobin-associated PO2 averaged 3.1 +/- .3 (N) and 2.1 +/- .2 mmHg (H). At maximal exercise, measurements of arterial PO2 (115 +/- 4 [N] and 46 +/- 1 mmHg [H]) and femoral venous PO2 (22 +/- 1.6 [N] and 17 +/- 1.3 mmHg [H]) resulted in calculated mean capillary PO2 values of 38 +/- 2 (N) and 30 +/- 2 mmHg(H). Thus, for the first time, large differences in PO2 between blood and intracellular tissue have been demonstrated in intact normal human muscle and are found over a wide range of exercise intensities. These data are consistent with an O2 diffusion limitation across the 1-5-microns path-length from red cell to the sarcolemma that plays a role in determining maximal muscle O2 uptake in normal humans. PMID:7560083

  12. Using squat testing to predict training loads for lower-body exercises in elite karate athletes.

    PubMed

    Wong, Del P; Tan, Erik C H; Chaouachi, Anis; Carling, Christopher; Castagna, Carlo; Bloomfield, Jonathan; Behm, David G

    2010-11-01

    The purpose of this study was to determine the relationship between squat loads and 2 bilateral and 2 unilateral stepping lower-body exercises in predominantly unilateral movement elite athletes (Karate). Equations to predict loads for lower-body exercises based on the squat load were also determined. Fourteen male elite Karate athletes (age = 22.6 ± 1.2 years) performed 6 repetition maximum (RM) of the following free-weight bilateral exercises: back half squat, deadlift, leg press and unilateral stepping exercises, lunge; and step-up. Results showed that 6RM squat load was significantly (p < 0.001) correlated with deadlift (r = 0.86), leg press (r = 0.76), lunge (r = 0.86), and step-up (r = 0.92). Linear regression showed that the 6RM squat load was a significant predictor for deadlift, leg press, lunge, and step-up (R2 range from 0.57 to 0.85, p < 0.001). The following 6RM prediction equations were determined: (a) Deadlift = squat load (1.12)-16.60 kg, (b) Leg press = squat load (1.66) + 16.10 kg, (c) Lunge = squat load (0.61) + 9.39 kg, and (d) step-up = squat load (0.85)-10.36 kg. Coaches and fitness professionals can use the 6RM squat load as a time effective and accurate method to predict training loads for both bilateral and unilateral lower-body exercises with quadriceps as the prime mover. Load prescriptions for unilateral exercises should take into account the type of athletic population. PMID:20838250

  13. Exercise for the Overweight Patient.

    ERIC Educational Resources Information Center

    Work, Janis A.

    1990-01-01

    Exercise can help patients maintain lean body mass during weight loss. Although exercise is not extremely useful in shedding excess pounds, it helps keep off weight lost through calorie restriction. This article discusses the specifics of exercise prescription, types of exercise, motivation to exercise, and special problems such as diabetes. (SM)

  14. Candidate Exercise Technologies and Prescriptions

    NASA Technical Reports Server (NTRS)

    Loerch, Linda H.

    2010-01-01

    This slide presentation reviews potential exercise technologies to counter the effects of space flight. It includes a overview of the exercise countermeasures project, a review of some of the candidate exercise technologies being considered and a few of the analog exercise hardware devices, and a review of new studies that are designed to optimize the current and future exercise protocols.

  15. Advanced Resistive Exercise Device

    NASA Technical Reports Server (NTRS)

    Raboin, Jasen; Niebuhr, Jason; Cruz, Santana; Lamoreaux, chris

    2007-01-01

    The advanced resistive exercise device (ARED), now at the prototype stage of development, is a versatile machine that can be used to perform different customized exercises for which, heretofore, it has been necessary to use different machines. Conceived as a means of helping astronauts and others to maintain muscle and bone strength and endurance in low-gravity environments, the ARED could also prove advantageous in terrestrial settings (e.g., health clubs and military training facilities) in which many users are exercising simultaneously and there is heavy demand for use of exercise machines.

  16. Exercise in cancer

    PubMed Central

    Rajarajeswaran, P.; Vishnupriya, R.

    2009-01-01

    Physical exercise has attracted increased interest in rehabilitation of oncological patients. The purpose of this paper is to review the literature and summarize the evidence of physical exercise in preventing cancer, its ability in attenuating the effect of cancer and its treatments and to provide guidelines for exercise prescription Review of recent literature by electronic search of MEDline (Pub Med), Cancer lit, Cochrane libraries, CINAHL were done using Keywords and the variables were identified and systematically evaluated. There is strong evidence for reduced risk of colorectal and breast cancer with possible association for prostate, endometrial and lung cancer with increasing physical activity. Exercise helps cancer survivors cope with and recover from treatment; exercise may improve the health of long term cancer survivors and extend survival. Physical exercise will benefit throughout the spectrum of cancer. However, an understanding of the amount, type and intensity of exercise needed has not been fully elucidated. There is sufficient evidence to promote exercise in cancer survivors following careful assessment and tailoring on exercise prescription. PMID:20596305

  17. Home-Based Exercise

    MedlinePLUS

    ... at a prescribed pace. Balance-strengthening and general fitness The success of any balance-retraining program depends in part on good general fitness. Progressive fitness programs increase energy and reduce stress. ...

  18. How Exercise Can Help

    MedlinePLUS Videos and Cool Tools

    ... they need to improve muscle tone around the joint -- it actually protects the joint. Dr. Roland Moskowitz: If you strengthen the muscles and stabilize the joint, you decrease the instability of the joint. Instability ...

  19. Strengthening Family Practices for Latino Families

    PubMed Central

    Chartier, Karen G.; Negroni, Lirio K.; Hesselbrock, Michie N.

    2010-01-01

    The study examined the effectiveness of a culturally-adapted Strengthening Families Program (SFP) for Latinos to reduce risks for alcohol and drug use in children. Latino families, predominantly Puerto Rican, with a 9–12 year old child and a parent(s) with a substance abuse problem participated in the study. Pre- and post-tests were conducted with each family. Parental stress, parent-child dysfunctional relations, and child behavior problems were reduced in the families receiving the intervention; family hardiness and family attachment were improved. Findings contribute to the validation of the SFP with Latinos, and can be used to inform social work practice with Puerto Rican families. PMID:20871785

  20. Magnesium carbonate precipitate strengthened aerobic granules.

    PubMed

    Lee, Duu-Jong; Chen, Yu-You

    2015-05-01

    Aerobic granules were precipitated internally with magnesium carbonate to enhance their structural stability under shear. The strengthened granules were tested in continuous-flow reactors for 220 days at organic loadings of 6-39 kg/m(3)/day, hydraulic retention times of 0.44-19 h, and temperatures of 10 or 28C. The carbonate salt had markedly improved the granule strength without significant changes in granule morphology or microbial communities (with persistent strains Streptomyces sp., Rhizobium sp., Brevundimonas sp., and Nitratireductor sp.), or sacrifice in biological activity for organic degradation. MgCO3 precipitated granules could be used in continuous-flow reactor for wastewater treatment at low cost and with easy processing efforts. PMID:25727761

  1. p53: exercise capacity and metabolism

    PubMed Central

    Wang, Ping-yuan; Zhuang, Jie; Hwang, Paul M.

    2014-01-01

    Purpose of review There is an inverse relationship between cancer incidence and cardiorespiratory fitness in large population studies. Mechanistic insights into these observations may strengthen the rationale for encouraging exercise fitness in the clinics for cancer prevention and may promote the development of new preventive strategies. Recent findings Studying the multi-faceted activities of p53, a critical tumor suppressor gene, has revealed various cellular pathways necessary for adapting to environmental stresses. Genetic connections are being made between p53 and an increasing number of metabolic activities such as oxidative phosphorylation, glycolysis and fatty acid oxidation. In vivo mouse models show that p53 plays an important role in determining both basal aerobic exercise capacity and its improvement by training. Summary The genetic pathways by which p53 regulates metabolism and exercise may help explain significant epidemiologic observations connecting cardiorespiratory fitness and cancer. Further understanding of these molecular pathways through human translational studies may promote the development of new cancer preventive strategies. PMID:22123233

  2. Exercise and diabetes.

    PubMed

    Chipkin, S R; Klugh, S A; Chasan-Taber, L

    2001-08-01

    As rates of diabetes mellitus and obesity continue to increase, physical activity continues to be a fundamental form of therapy. Exercise influences several aspects of diabetes, including blood glucose concentrations, insulin action and cardiovascular risk factors. Blood glucose concentrations reflect the balance between skeletal muscle uptake and ambient concentrations of both insulin and counterinsulin hormones. Difficulties in predicting the relative impact of these factors can result in either hypoglycemia or hyperglycemia. Despite the variable impact of exercise on blood glucose, exercise consistently improves insulin action and several cardiovascular risk factors. Beyond the acute impact of physical activity, long-term exercise behaviors have been repeatedly associated with decreased rates of type 2 diabetes. While exercise produces many benefits, it is not without risks for patients with diabetes mellitus. In addition to hyperglycemia, from increased hepatic glucose production, insufficient insulin levels can foster ketogenesis from excess concentrations of fatty acids. At the opposite end of the glucose spectrum, hypoglycemia can result from excess glucose uptake due to either increased insulin concentrations, enhanced insulin action or impaired carbohydrate absorption. To decrease the risk for hypoglycemia, insulin doses should be reduced prior to exercise, although some insulin is typically still needed. Although precise risks of exercise on existing diabetic complications have not been well studied, it seems prudent to consider the potential to worsen nephropathy or retinopathy, or to precipitate musculoskeletal injuries. There is more substantive evidence that autonomic neuropathy may predispose patients to arrhythmias. Of clear concern, increased physical activity can precipitate a cardiac event in those with underlying CAD. Recognizing these risks can prompt actions to minimize their impact. Positive actions that are part of exercise programs for diabetic patients emphasize SMBG, foot care and cardiovascular functional assessment. SMBG provides critical information on the impact of exercise and is recommended for all patients before, during and after exercise. More frequent monitoring (and for longer periods following exercise) is recommended for those with hypoglycemia unawareness or those performing high-intensity exercise. Preventing the sequelae of an exercise-induced severe hypoglycemic reaction can be as simple as carrying glucose tablets or gel, a diabetic identification bracelet or card, or exercising with an individual who is aware of the circumstances. In addition to blood glucose concentrations, proper foot care is critical to people with diabetes who exercise and includes considering type of shoe, type of exercise, inspection of skin surfaces and appropriate evaluation and treatment of lesions (calluses and others). Those with severe neuropathy can consider alternatives to weight-bearing exercises. Precipitation of clinical CAD is of great concern for all diabetic patients participating in exercise activities. Although a sufficiently sensitive and specific screening test for coronary disease has not been identified, those planning an exercise program of moderate intensity or greater should be evaluated. Initial cardiac assessment should include exercise testing as well as identifying risk for autonomic neuropathy. In addition to noting maximal heart rate and blood pressure as well as ischemic changes, exercise tolerance testing can identify anginal thresholds and patients with asymptomatic ischemia. Those without symptoms should be counseled regarding target pulse rates to avoid inducing ischemia. Ischemic changes need to be evaluated for either further diagnostic testing or pharmacological intervention. For patients with diabetes mellitus, the overall benefits of exercise are clearly significant. Clinicians and patients must work together to maximize these benefits while minimizing risks for negative consequences. Identifying and preventing potential problems beforehand can reduce adverse outcomes and promote this important approach to healthy living. PMID:11570119

  3. Dose-response of strengthening exercise for treatment of severe neck pain in women.

    PubMed

    Andersen, Christoffer H; Andersen, Lars L; Pedersen, Mogens T; Mortensen, Peter; Karstad, Kristina; Mortensen, Ole S; Zebis, Mette K; Sjøgaard, Gisela

    2013-12-01

    Specific strength training is shown to relieve neck pain in office workers. The purpose of this study is to evaluate the effectiveness of specific strength training in women with severe neck pain and to analyze the dose-response relationship between training adherence and pain reduction. One hundred eighteen untrained women with severe neck pain (>30 mm VAS pain) were included from a larger study, in which the subjects were randomized to 20-week specific strength training for the neck/shoulders or to a control group. In the intention-to-treat analysis, the training group experienced greater pain relief than the control group (p < 0.01). Participants who adhered "per protocol" decreased pain by 35 mm VAS (95% confidence interval: -26 to -44) from baseline to follow-up corresponding to a 70% reduction. In the dose-response analyses, participants with medium and high training adherence showed better pain relief than the control group and those with low adherence (p < 0.0001). The decrease from baseline in the medium and high adherence groups was 37 mm VAS (28-46 mm) and 33 mm VAS (24-43 mm), respectively. Specific strength training reduces pain intensity in women with severe neck pain, and 1-2 training sessions per week for 20 weeks (∼30 training sessions) seems sufficient for optimal pain relief. PMID:23478473

  4. The effects of topical Arnica on performance, pain and muscle damage after intense eccentric exercise.

    PubMed

    Pumpa, Kate L; Fallon, Kieran E; Bensoussan, Alan; Papalia, Shona

    2014-01-01

    The aim of the study was to determine if topical Arnica is effective in reducing pain, indicators of inflammation and muscle damage, and in turn improve performance in well-trained males experiencing delayed onset muscle soreness (DOMS). Twenty well-trained males matched by maximal oxygen uptake (V̇O2 Max) completed a double-blind, randomised placebo-controlled trial. Topical Arnica was applied to the skin superficial to the quadriceps and gastrocnemius muscles immediately after a downhill running protocol designed to induce DOMS. Topical Arnica was reapplied every 4 waking hours for the duration of the study. Performance measures (peak torque, countermovement and squat jump), pain assessments (visual analogue scale (VAS) and muscle tenderness) and blood analysis (interleukin-1 beta, interleukin-6, tumour necrosis factor-alpha, C-reactive protein, myoglobin and creatine kinase) were assessed at seven time points over five days (pre-, post-, 4, 24, 48, 72 and 96 hours after the downhill run). Participants in the topical Arnica group reported less pain as assessed through muscle tenderness and VAS 72 hours post-exercise. The application of topical Arnica did not affect any performance assessments or markers of muscle damage or inflammation. Topical Arnica used immediately after intense eccentric exercise and for the following 96 hours did not have an effect on performance or blood markers. It did however demonstrate the possibility of providing pain relief three days post-eccentric exercise. PMID:23947690

  5. Exercise and diabetes.

    PubMed

    Zisser, H; Gong, P; Kelley, C M; Seidman, J S; Riddell, M C

    2011-02-01

    Diet and exercise form the foundation of a healthy lifestyle. These are especially important for people living with diabetes mellitus, as they are the most practical non-pharmacological means by which patients may significantly improve their blood glucose levels. Exercise increases insulin sensitivity (both short and long term), lowers blood sugar levels, reduces body fat and improves cardiovascular (CV) function. Because of this, exercise offers enormous benefit to patients with diabetes. Blood glucose levels can significantly drop during and after physical activities, due to the increased utilisation of glucose as a fuel during exercise and the up-regulation of glucose transport into working muscles. Therefore, patients (especially those with type 1 diabetes) must account for the effects of exercise and adjust their medications and nutrition accordingly. Improvements in real-time continuous glucose monitoring and optimisation of basal insulin dosing may offer significant benefit to preventing hypoglycaemia in patients with type 1 diabetes who regularly exercise. Diverse exercise programmes and devices can also assist patients in monitoring their activities as well as motivating them to achieve their exercise goals. For patients with type 1 diabetes, questions such as how much, how long, how strenuous and what kind of exercise must be addressed in order for healthcare professionals to offer maximum benefit to their patients. Additionally, since patients with type 2 diabetes often have other significant co-morbidities such as obesity and CV disease, care providers must evaluate each patient's risk factors before designing an exercise programme. Several publications in the last year have addressed these issues and may serve as a valuable resource to provide safe and effective recommendations to patients and their healthcare providers. To be included in the Exercise and Diabetes chapter for the 2010 YEARBOOK, we reviewed leading peer-reviewed manuscripts that were published in the period July 2009 to June 2010. PubMed was used in the initial screening of articles. PMID:21323815

  6. Role of manual therapy with exercise regime versus exercise regime alone in the management of non-specific chronic neck pain.

    PubMed

    Akhter, Saeed; Khan, Muhammad; Ali, Syed Shahzad; Soomro, Rabial Rani

    2014-11-01

    To evaluate the role of manual therapy with exercise regime versus exercise regime alone in the management of non-specific chronic neck pain. In this 62 subjects randomized controlled trial 31 subjects in group A received manual therapy (manipulation) with supervised exercise regime whilst 31 subjects in group B performed only supervised exercise regime for the period of 3 weeks. Both groups had a home exercise program consisted of strengthening exercises for neck/scapuluar stability, stretching and general range of motion exercises for neck with advice regarding posture awareness and correction for 3 months. The results suggested significant reduction in pain intensity level in both groups; over 3 weeks and 12 weeks' time period in relation to baseline on visual analog scale (p=0.001). Similarly, statistically significant improvements noticed in Neck Disability Index (NDI) (p=0.0001) in both groups while looking at baseline data with reference to 12 weeks' time period. On closer inspection, the manual therapy (manipulation) with exercise regime appeared as a favorable treatment preference compared with exercise regime alone. PMID:25410083

  7. Exercise-Induced Changes in Caveolin-1, Depletion of Mitochondrial Cholesterol, and the Inhibition of Mitochondrial Swelling in Rat Skeletal Muscle but Not in the Liver

    PubMed Central

    Flis, Damian Jozef; Olek, Robert Antoni; Kaczor, Jan Jacek; Rodziewicz, Ewa; Halon, Malgorzata; Wozniak, Michal; Gabbianelli, Rosita; Ziolkowski, Wieslaw

    2016-01-01

    The reduction in cholesterol in mitochondria, observed after exercise, is related to the inhibition of mitochondrial swelling. Caveolin-1 (Cav-1) plays an essential role in the regulation of cellular cholesterol metabolism and is required by various signalling pathways. Therefore, the aim of this study was to investigate the effect of prolonged swimming on the mitochondrial Cav-1 concentration; additionally, we identified the results of these changes as they relate to the induction of changes in the mitochondrial swelling and cholesterol in rat skeletal muscle and liver. Male Wistar rats were divided into a sedentary control group and an exercise group. The exercised rats swam for 3 hours and were burdened with an additional 3% of their body weight. After the cessation of exercise, their quadriceps femoris muscles and livers were immediately removed for experimentation. The exercise protocol caused an increase in the Cav-1 concentration in crude muscle mitochondria; this was related to a reduction in the cholesterol level and an inhibition of mitochondrial swelling. There were no changes in rat livers, with the exception of increased markers of oxidative stress in mitochondria. These data indicate the possible role of Cav-1 in the adaptive change in the rat muscle mitochondria following exercise. PMID:26839631

  8. Exercise-Induced Changes in Caveolin-1, Depletion of Mitochondrial Cholesterol, and the Inhibition of Mitochondrial Swelling in Rat Skeletal Muscle but Not in the Liver.

    PubMed

    Flis, Damian Jozef; Olek, Robert Antoni; Kaczor, Jan Jacek; Rodziewicz, Ewa; Halon, Malgorzata; Antosiewicz, Jedrzej; Wozniak, Michal; Gabbianelli, Rosita; Ziolkowski, Wieslaw

    2016-01-01

    The reduction in cholesterol in mitochondria, observed after exercise, is related to the inhibition of mitochondrial swelling. Caveolin-1 (Cav-1) plays an essential role in the regulation of cellular cholesterol metabolism and is required by various signalling pathways. Therefore, the aim of this study was to investigate the effect of prolonged swimming on the mitochondrial Cav-1 concentration; additionally, we identified the results of these changes as they relate to the induction of changes in the mitochondrial swelling and cholesterol in rat skeletal muscle and liver. Male Wistar rats were divided into a sedentary control group and an exercise group. The exercised rats swam for 3 hours and were burdened with an additional 3% of their body weight. After the cessation of exercise, their quadriceps femoris muscles and livers were immediately removed for experimentation. The exercise protocol caused an increase in the Cav-1 concentration in crude muscle mitochondria; this was related to a reduction in the cholesterol level and an inhibition of mitochondrial swelling. There were no changes in rat livers, with the exception of increased markers of oxidative stress in mitochondria. These data indicate the possible role of Cav-1 in the adaptive change in the rat muscle mitochondria following exercise. PMID:26839631

  9. Exercises to help prevent falls

    MedlinePLUS

    ... can be active You can do the following exercises anytime and almost anywhere. As you get stronger, ... your ankles. This will increase how effective the exercise is. Try to exercise 2 or more days ...

  10. Stay active and exercise - arthritis

    MedlinePLUS

    ... your overall health and sense of well-being. Exercise keeps your muscles strong and increases your range ... Water exercises may be the best exercise for your arthritis. Swimming laps, water aerobics, or even just walking in ...

  11. Exercise Eases Low Back Pain

    MedlinePLUS

    ... medlineplus/news/fullstory_156634.html Exercise Eases Low Back Pain Review of studies shows exercise, with or without ... News) -- Exercise may reduce your risk of low back pain, Australian researchers report. They reviewed 23 studies that ...

  12. Structural improvement of strengthened deck panels with externally bonded plates

    SciTech Connect

    Sim, Jongsung; Oh, Hongseob . E-mail: opera69@chollian.net

    2005-07-01

    Concrete bridge decks require eventual replacement and rehabilitation due to decreasing load-carrying capacity. This paper compares different strengthening design procedures that improve the usability and structural performance of bridge decks. The failure characteristics of bridge decks strengthened with various materials such as carbon fiber sheet, glass fiber sheet, steel plate, and grid CFRP and GFRP are analyzed, and the theoretical load-carrying capacities are evaluated using traditional beam and yield line theory, and punching shear analysis. The strengthening materials increase the punching shear strength of the deck and change the failure mode of the strengthened panel.

  13. Fatigue test of RC beams strengthened with prestressed CFLs

    NASA Astrophysics Data System (ADS)

    Guo, Xinyan; Huang, Peiyan; Liu, Guangwan; Xie, Jianhe

    2008-11-01

    Applying prestress to fiber reinforced polymer (FRP) can be used more efficiently since a greater portion energy of its tensile capacity is engaged. Based on carbon fiber laminate (CFL), fatigue tests are made to find out the fatigue behavior of reinforced concrete (RC) beams strengthened with prestressed CFL. The interfacial debonding is a main failure mode for RC beams strengthened with prestressed CFLs under the cyclic loading. Furthermore, it has been found that the stress value of CFLs decide whether the additional prestressing has a negative or positive effect on the fatigue behavior of the strengthened beam, and the excessive prestressing would reduce the fatigue life of the strengthened beam.

  14. Evaluating the performance of skewed prestressed concrete bridge after strengthening

    NASA Astrophysics Data System (ADS)

    Naser, Ali Fadhil; Zonglin, Wang

    2013-06-01

    The objectives of this paper are to explain the application of repairing and strengthening methods on the damaged members of the bridge structure, to analyze the static and dynamic structural response under static and dynamic loads after strengthening, and to evaluate the structural performance after application of strengthening method. The repairing and strengthening methods which are used in this study include treatment of the cracks, thickening the web of box girder along the bridge length and adding internal pre-stressing tendons in the thickening web, and construct reinforced concrete cross beams (diaphragms) between two box girders. The results of theoretical analysis of static and dynamic structural responses after strengthening show that the tensile stresses are decreased and become less than the allowable limit values in the codes. The values of vertical deflection are decreased after strengthening. The values of natural frequencies after strengthening are increased, indicating that the strengthening method is effective to reduce the vibration of the bridge structure. Therefore, the strengthening methods are effective to improve the bearing capacity and elastic working state of the bridge structure and to increase the service life of the bridge structure.

  15. [Institutional strengthening and updating of the National Academy of Medicine of Mexico (results and instrumentalization 2010-2012)].

    PubMed

    Ruiz de Chávez, Manuel H; Kershenobich, David; Mansilla Olivares, Armando; Mancilla Ramírez, Javier; Kuri Morales, Pablo; Del Valle Muñoz, Alejandro

    2011-01-01

    In order to strengthen the academic and social management of the National Academy of Medicine of Mexico, from the draft paper presented to run for Vice President of the corporation, in 2007 I proposed to the plenary of the institution to develop a planning exercise strategy, in fact supporting the achievement of that objective. The idea behind the proposal, which was supported by most scholars, started from the consideration that although the Academy has always been an area of excellence for the advancement of medicine in the country, it was now necessary to strengthen, modernize and give a new direction to its work, on the basis of an exercise analysis and background checks, work, commitment and vision, under a inclusive, plural and agreed strategy with the academic body of the corporation, i.e. through a designed planning exercise. The result of this surely positive effort is presented in the following pages. To this end, part of the initial project description illustrates the process of technical and methodological development, the lines of action considered as priorities by academics, and details involving its realization. This planning strategy project yielded three specific conclusions: (i) the necessity for a functional reorganization proposal of the Academy's structure; (ii) the need for a self-sustainability financial project to fortify the economic capacity of the Academy; and (iii) the need for an updated project on technological communication of the Academy. PMID:21412397

  16. Exercises in Policy Analysis.

    ERIC Educational Resources Information Center

    Nagel, Stuart S.

    1980-01-01

    Describes a series of exercises which were developed to teach the basic methodologies involved in analyzing and evaluating the effects of alternative public policies. The exercises, intended for use on the college level, deal with determining causation in policy analysis, finding optimum choices with different probabilities, and finding an optimum…

  17. Exercise through Menopause.

    ERIC Educational Resources Information Center

    Stuhr, Robyn M.

    2002-01-01

    Menopause is associated with many different health effects and symptoms. This paper explains that regular exercise can play a critical role in protecting health and battling the increased risk of cardiovascular disease, osteoporosis, pelvic floor atrophy, and joint stiffness associated with menopause. Exercise programs for menopausal women should

  18. Saliva composition and exercise.

    PubMed

    Chicharro, J L; Lucía, A; Pérez, M; Vaquero, A F; Ureña, R

    1998-07-01

    Little attention has been directed toward identifying the changes which occur in salivary composition in response to exercise. To address this, our article first refers to the main aspects of salivary gland physiology. A knowledge of the neural control of salivary secretion is especially important for the understanding of the effects of exertion on salivary secretion. Both salivary output and composition depend on the activity of the autonomic nervous system and any modification of this activity can be observed indirectly by alternations in the salivary excretion. The effects of physical activity (with reference to factors such as exercise intensity and duration, or type of exercise protocol) on salivary composition are then considered. Exercise might indeed induce changes in several salivary components such as immunoglobulins, hormones, lactate, proteins and electrolytes. Saliva composition might therefore be used as an alternative noninvasive indicator of the response of the different body tissues and systems to physical exertion. In this respect, the response of salivary amylase and salivary electrolytes to incremental levels of exercise is of particular interest. Beyond a certain intensity of exercise, and coinciding with the accumulation of blood lactate (anaerobic threshold or AT), a 'saliva threshold' (Tsa) does indeed exist. Tsa is the point during exercise at which the levels of salivary alpha-amylase and electrolytes (especially Na+) also begin to rise above baseline levels. The occurrence of the 2 thresholds (AT and Tsa) might, in turn, be attributable to the same underlying mechanism, that of increased adrenal sympathetic activity at high exercise intensities. PMID:9739538

  19. Water Exercise Causes Ripples.

    ERIC Educational Resources Information Center

    Koszuta, Laurie Einstein

    1986-01-01

    Water exercise provides benefits independently of participants' skill levels, and reduces the likelihood of injury from overuse syndromes and heat-related problems. The advantages of water resistance exercises for athletes and for elderly, overweight, or physically disabled people are discussed. (MT)

  20. Exercise Against Depression.

    ERIC Educational Resources Information Center

    Artal, Michal; Sherman, Carl

    1998-01-01

    Physical activity is useful for preventing and easing depression symptoms. When prescribing exercise as an adjunct to medication and psychotherapy, physicians must consider each patient's individual circumstances. Hopelessness and fatigue can make physical exercise difficult. A feasible, flexible, and pleasurable program has the best chance for…