Voluntary Inducement of Triceps Surae Muscle Cramping

2013 ◽  
Vol 18 (6) ◽  
pp. 40-43 ◽  
Author(s):  
Ashley Goodman ◽  
Kevin A. Zwetsloot

Context:Exercise-associated muscle cramping (EAMC) is difficult to induce experimentally.Purpose:T o assess the reliability of a maximum voluntary contraction (MVC) procedure for inducement of a muscle cramp.Participants:Seventy-four healthy and physically active participants (23 ± 8 years of age; 49 males and 25 females); 63 who had previously experienced EAMC.Main Outcome Measure:Each participant’s triceps surae musculature was placed in a shortened and unloaded position. Participants were instructed to maximally contract the triceps surae musculature with the intent to induce a cramp within 60 seconds.Results:Cramping was induced in 31% of participants within 60 seconds, and 97% of participants who experienced cramping during the initial session and who returned for two subsequent testing sessions at one-week intervals reproduced cramping with the procedure.Conclusions:The MVC procedure consistently induced cramping in a subset of 18 cramp-prone participants during multiple testing sessions, which suggests that it may have value as a screening tool for identification of athletes with a predisposition for EAMC.

2000 ◽  
Vol 9 (3) ◽  
pp. 229-239 ◽  
Author(s):  
William R. Holcomb ◽  
Shahin Golestani ◽  
Shante Hill

Context:Neuromuscular electrical stimulation (NMES) can be used to prevent the atrophy and strength loss associated with immobilization.Objective:To compare the effects of biphasic current and the modulated “Russian” current on muscular torque production during different contraction conditions.Design, Setting, and Participants:In a within-subjects design, 10 healthy subjects in an athletic training laboratory received NMES.Interventions:Isometric knee-extension torque was recorded with the Biodex™ under 4 conditions: maximum voluntary contraction (MVC; control), MVC superimposed with low-intensity stimulation (sham), MVC superimposed with high-intensity stimulation, and high-intensity stimulation only.Main Outcome Measure:Data normalized for body weight were analyzed using a 2 (current type) X 4 (condition) repeated-measures analysis of variance.Results:The main effect for current type was not significant, F1,9 = .03, P = .87.


2007 ◽  
Vol 98 (3) ◽  
pp. 1102-1107 ◽  
Author(s):  
Serajul I. Khan ◽  
John A. Burne

Muscle cramp was induced in one head of the gastrocnemius muscle (GA) in eight of thirteen subjects using maximum voluntary contraction when the muscle was in the shortened position. Cramp in GA was painful, involuntary, and localized. Induction of cramp was indicated by the presence of electromyographic (EMG) activity in one head of GA while the other head remained silent. In all cramping subjects, reflex inhibition of cramp electrical activity was observed following Achilles tendon electrical stimulation and they all reported subjective relief of cramp. Thus muscle cramp can be inhibited by stimulation of tendon afferents in the cramped muscle. When the inhibition of cramp-generated EMG and voluntary EMG was compared at similar mean EMG levels, the area and timing of the two phases of inhibition (I1, I2) did not differ significantly. This strongly suggests that the same reflex pathway was the source of the inhibition in both cases. Thus the cramp-generated EMG is also likely to be driven by spinal synaptic input to the motorneurons. We have found that the muscle conditions that appear necessary to facilitate cramp, a near to maximal contraction of the shortened muscle, are also the conditions that render the inhibition generated by tendon afferents ineffective. When the strength of tendon inhibition in cramping subjects was compared with that in subjects that failed to cramp, it was found to be significantly weaker under the same experimental conditions. It is likely that reduced inhibitory feedback from tendon afferents has an important role in generating cramp.


2010 ◽  
Vol 45 (4) ◽  
pp. 333-337 ◽  
Author(s):  
David O. Draper ◽  
Clinton G. Edvalson ◽  
Kenneth L. Knight ◽  
Dennis Eggett ◽  
Joseph Shurtz

Abstract Context: Although originally manufactured for use in diagnostic imaging of internal structures, 2-cm-thick gel pads are also used as conducting media for therapeutic ultrasound over areas with bony prominences. Research on the ability of these pads to conduct enough energy to adequately heat tissues has provided mixed results. However, this research has mainly been performed on the triceps surae muscle, an area over which gel pads are not typically used. We wondered how much heating might be produced if a thinner pad was used over a tendon. Objective: To compare temperature rises in the human Achilles tendon during ultrasound treatments using ultrasound gel, a 2-cm-thick pad, and a 1-cm-thick pad. Design: Cross-sectional study. Setting: University therapeutic modality laboratory. Patients or Other Participants: Forty-eight healthy volunteers (24 women, 24 men). Intervention(s): We inserted a rigid thermocouple 1 cm deep into the Achilles tendon. Ultrasound was delivered at the following settings: 3 MHz, continuous, 1 W/cm2, 10 minutes. Main Outcome Measure(s): Temperature was recorded every 30 seconds for 10 minutes. Results: Temperature increased the most in the ultrasound gel group (increase  =  13.3°C, peak  =  42°C). The 1-cm-thick pad resulted in higher tendon temperature (increase  =  9.3°C, peak  =  37.8°C) than the 2-cm-thick pad (increase  =  6.5°C, peak  =  4.8°C). The 1-cm pad produced approximately 30% more heating than the 2-cm pad (SE  =  0.72, P < .03). Conclusions: The thinner pad transmitted ultrasound more efficiently than the thicker pad. Thus, a gel pad of less than 1-cm thickness might be useful for superficial areas, such as the hands and ankles.


2000 ◽  
Vol 88 (5) ◽  
pp. 1698-1706 ◽  
Author(s):  
K. Roeleveld ◽  
B. G. M. van Engelen ◽  
D. F. Stegeman

In this study, the initiation and development of muscle cramp are investigated. For this, we used a 64-channel surface electromyogram (EMG) to study the triceps surae muscle during both cramp and maximal voluntary contraction (MVC) in four cramp-prone subjects and during cramp only in another four cramp-prone subjects. The results show that cramp presents itself as a contraction of a slowly moving fraction of muscle fibers, indicating that either the spatial arrangement of the motoneurons and muscle fibers is highly related or that cramp spreads at a level close to the muscle. Spectral analyses of the EMG and peak-triggered average potentials show the presence of extremely short potentials during cramp compared with during MVC. These results can also be interpreted in two ways. Either the motoneurons fire with enlarged synchronization during MVC compared with cramp, or smaller units than motor units are active, indicating that cramp is initiated close to or even at the muscle fiber level. Further research is needed to draw final conclusions.


Author(s):  
Theodore Dassios ◽  
Emma E Williams ◽  
Ann Hickey ◽  
Catey Bunce ◽  
Anne Greenough

ObjectivesTo report the current incidence of bronchopulmonary dysplasia (BPD) and to compare changes in weight and head circumference between infants who developed BPD and infants who did not.DesignRetrospective, whole-population study.SettingAll neonatal units in England between 2014 and 2018.PatientsAll liveborn infants born <28 completed weeks of gestation.InterventionsThe change in weight z-score (ΔWz) was calculated by subtracting the birthweight z-score from the weight z-score at 36 weeks postmenstrual age (PMA) and at discharge. The change in head circumference z-score (ΔHz) was calculated by subtracting the birth head circumference z-score from the head circumference z-score at discharge.Main outcome measureBPD was defined as the need for any respiratory support at 36 weeks PMA.Results11 806 infants were included in the analysis. The incidence of BPD was 57.5%, and 18.9% of the infants died before 36 weeks PMA. The median (IQR) ΔWz from birth to 36 weeks PMA was significantly smaller in infants who developed BPD (−0.69 (−1.28 to −0.14), n=6105) than in those who did not develop BPD (−0.89 (−1.40 to −0.33), n=2390; adjusted p<0.001). The median (IQR) ΔHz from birth to discharge was significantly smaller in infants who developed BPD (−0.33 (−1.69 to 0.71)) than in those who did not develop BPD (−0.61 (−1.85 to 0.35); adjusted p<0.001).ConclusionsPostnatal growth was better in infants diagnosed with BPD compared with infants without BPD possibly due to more aggressive nutrition strategies.


2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P127-P128
Author(s):  
Robert L Harris ◽  
Grundy Alan ◽  
Tunde A Odutoye

Objectives Radiological balloon dilatation of lower oesophageal strictures is common practice. Other than some early reports from our own centre, there is little published regarding radiological dilatation of pharyngeal and upper oesophageal strictures and less still on radiological balloon dilatation of post-total laryngectomy and pharyngolaryngectomy neo-pharyngeal strictures. Standard practise is bouginage under general anaesthaesia. The objective of this study is to assess the efficacy of radiological balloon dilatation for the treatment of dysphagia secondary to neopharyngeal strictures in patients who have undergone laryngectomy. Methods A tertiary care centre case series of 20 consecutive patients (17 males and 3 females aged 40 to 84) with pharyngeal stricture and dysphagia post-total laryngectomy or pharyngolaryngectomy who underwent balloon dilatation of the stricture under radiological guidance. Maintenance of swallowing was the main outcome measure. Results 5 patients gained relief of their dysphagia with 1 balloon dilatation only. 9 patients required more than 1 dilatation to maintain swallowing. 2 patients had balloon dilatation procedures and stent insertion for palliative relief of dysphagia from known recurrent malignant disease. 3 patients failed to maintain swallowing with repeat dilatations. No patients suffered any significant complications such as perforation. Conclusions Balloon dilatation is minimally invasive and less traumatic than rigid pharyngoscopy with bouginage dilatation. It is well tolerated. It may be repeated frequently and can successfully relieve strictures of the pharynx in patients who have undergone total laryngectomy or pharyngolaryngectomy.


2021 ◽  
pp. 105566562199610
Author(s):  
Buddhathida Wangsrimongkol ◽  
Roberto L. Flores ◽  
David A. Staffenberg ◽  
Eduardo D. Rodriguez ◽  
Pradip. R. Shetye

Objective: This study evaluates skeletal and dental outcomes of LeFort I advancement surgery in patients with cleft lip and palate (CLP) with varying degrees of maxillary skeletal hypoplasia. Design: Retrospective study. Method: Lateral cephalograms were digitized at preoperative (T1), immediately postoperative (T2), and 1-year follow-up (T3) and compared to untreated unaffected controls. Based on the severity of cleft maxillary hypoplasia, the sample was divided into 3 groups using Wits analysis: mild: ≤0 to ≥−5 mm; moderate: <−5 to >−10 mm; and severe: ≤−10 mm. Participants: Fifty-one patients with nonsyndromic CLP with hypoplastic maxilla who met inclusion criteria. Intervention: LeFort I advancement. Main Outcome Measure: Skeletal and dental stability post-LeFort I surgery at a 1-year follow-up. Results: At T2, LeFort I surgery produced an average correction of maxillary hypoplasia by 6.4 ± 0.6, 8.1 ± 0.4, and 10.7 ± 0.8 mm in the mild, moderate, and severe groups, respectively. There was a mean relapse of 1 to 1.5 mm observed in all groups. At T3, no statistically significant differences were observed between the surgical groups and controls at angle Sella, Nasion, A point (SNA), A point, Nasion, B point (ANB), and overjet outcome measures. Conclusions: LeFort I advancement produces a stable correction in mild, moderate, and severe skeletal maxillary hypoplasia. Overcorrection is recommended in all patients with CLP to compensate for the expected postsurgical skeletal relapse.


2020 ◽  
Vol 11 (1) ◽  
pp. 193-200
Author(s):  
Elizabeth Saunders ◽  
Brian C. Clark ◽  
Leatha A. Clark ◽  
Dustin R. Grooms

AbstractThe purpose of this study was to quantify head motion between isometric erector spinae (ES) contraction strategies, paradigms, and intensities in the development of a neuroimaging protocol for the study of neural activity associated with trunk motor control in individuals with low back pain. Ten healthy participants completed two contraction strategies; (1) a supine upper spine (US) press and (2) a supine lower extremity (LE) press. Each contraction strategy was performed at electromyographic (EMG) contraction intensities of 30, 40, 50, and 60% of an individually determined maximum voluntary contraction (MVC) (±10% range for each respective intensity) with real-time, EMG biofeedback. A cyclic contraction paradigm was performed at 30% of MVC with US and LE contraction strategies. Inertial measurement units (IMUs) quantified head motion to determine the viability of each paradigm for neuroimaging. US vs LE hold contractions induced no differences in head motion. Hold contractions elicited significantly less head motion relative to cyclic contractions. Contraction intensity increased head motion in a linear fashion with 30% MVC having the least head motion and 60% the highest. The LE hold contraction strategy, below 50% MVC, was found to be the most viable trunk motor control neuroimaging paradigm.


Author(s):  
Yung-Sheng Chen ◽  
Shi Zhou ◽  
Zachary J. Crowley-McHattan ◽  
Pedro Bezerra ◽  
Wei-Chin Tseng ◽  
...  

This study examined the acute effects of stretch tensions of kinesiology taping (KT) on the soleus (SOL), medial (MG), and lateral (LG) gastrocnemius Hoffmann-reflex (H-reflex) modulation in physically active healthy adults. A cross-over within-subject design was used in this study. Twelve physically active collegiate students voluntarily participated in the study (age = 21.3 ± 1.2 years; height = 175.6 ± 7.1 cm; body weight = 69.9 ± 7.1 kg). A standard Y-shape of KT technique was applied to the calf muscles. The KT was controlled in three tension intensities in a randomised order: paper-off, 50%, and 100% of maximal stretch tension of the tape. The peak-to-peak amplitude of maximal M-wave (Mmax) and H-reflex (Hmax) responses in the SOL, MG, and LG muscles were assessed before taping (pre-taping), taping, and after taping (post-taping) phases in the lying prone position. The results demonstrated significantly larger LG Hmax responses in the pre-taping condition than those in the post-taping condition during paper-off KT (p = 0.002). Moreover, the ΔHmax/Mmax of pre- and post-taping in the SOL muscle was significantly larger during 50%KT tension than that of paper-off (p = 0.046). In conclusion, the stretch tension of KT contributes minor influence on the spinal motoneuron excitability in the triceps surae during rest.


2008 ◽  
Vol 93 (12) ◽  
pp. 4840-4843 ◽  
Author(s):  
Enrico Brignardello ◽  
Andrea Corrias ◽  
Giuseppe Isolato ◽  
Nicola Palestini ◽  
Luca Cordero di Montezemolo ◽  
...  

Context: Childhood cancer survivors need regular monitoring into young adulthood and beyond, because they are at risk for developing late-onset complications of cancer therapy, including second malignancies. Objective: This study focuses on the use of thyroid ultrasound to screen for thyroid carcinoma in a population of childhood cancer survivors. Patients: A total of 129 subjects who had received radiotherapy to the head, neck, or upper thorax for a pediatric cancer were studied in the setting of a long-term follow-up unit. Design: Thyroid ultrasound usually began 5 yr after radiotherapy and was repeated every third year, if negative. Median follow-up time since childhood cancer diagnosis was 15.8 yr (range 6.1–34.8 yr). Solid thyroid nodules were found in 35 patients. Fine-needle aspiration was performed in 19 patients, of which 14 had nodules above 1 cm. Main Outcome Measure: The main outcome measure was the finding of not palpable thyroid cancers. Results: Cytological examination of specimens diagnosed papillary carcinoma in five patients who underwent surgery. The cytological diagnosis of papillary thyroid carcinoma was confirmed in all cases by histological examination. Notably, only two of these patients had palpable nodules; the other three were smaller than 1 cm and were detected only by ultrasound. However, histological examination showed nodal metastases in two of these. Conclusions: Although ultrasound screening for thyroid cancer in the general population is not cost effective and could lead to unnecessary surgery, due to false positives, we believe that in childhood cancer survivors who received radiotherapy involving the head, neck, or upper thorax, it would be worthwhile.


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