A Comparison of Knee-Extension Torque Production with Biphasic versus Russian Current

2000 ◽  
Vol 9 (3) ◽  
pp. 229-239 ◽  
Author(s):  
William R. Holcomb ◽  
Shahin Golestani ◽  
Shante Hill
Keyword(s):  
Athletic Training ◽  
High Intensity ◽  
Repeated Measures ◽  
Outcome Measure ◽  
Maximum Voluntary Contraction ◽  
Neuromuscular Electrical Stimulation ◽  
Strength Loss ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
Main Outcome Measure

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.

The Effect of Rest Intervals on Knee-Extension Torque Production with Neuromuscular Electrical Stimulation

2006 ◽  
Vol 15 (2) ◽  
pp. 116-124 ◽  
Author(s):  
William R. Holcomb ◽  
Mack D. Rubley ◽  
Michael G. Miller ◽  
Tedd J. Girouard
Keyword(s):  
Electrical Stimulation ◽  
Athletic Training ◽  
Outcome Measure ◽  
Neuromuscular Electrical Stimulation ◽  
Knee Extension ◽  
Rest Interval ◽  
Maximum Voluntary Isometric Contraction ◽  
Main Outcome Measure ◽  
Main Effect ◽  
Rest Intervals

Context:Previous studies using neuromuscular electrical stimulation (NMES) have suggested that 30-second rest intervals are too short for sufficient recovery.Objective:To compare the effect of rest interval on knee-extension torque production.Design:Counterbalanced mixed design to test independent variable, rest interval; ANOVA to analyze dependent variable, percentage decline.Setting:Athletic training research laboratory.Participants:24 healthy men and women.Intervention:Participants performed knee extension under 2 contraction conditions, maximum voluntary isometric contraction (MVIC) and NMES with either 30- or 120-second rest between repetitions.Main Outcome Measure:Peak torque produced during each repetition of a 5-repetition set.Results:The main effect for rest interval was significant (F1,23= 30.30,P= .001), as was the main effect for condition (F1,23= 11.18,P= .003).Conclusions:A 120-second rest between repetitions is recommended when using NMES in early rehabilitation because force decline across repetitions with 30-second rest during NMES is greater than with MVIC.

The Effects of Superficial Heating before 1-MHz Ultrasound on Tissue Temperature

2003 ◽  
Vol 12 (2) ◽  
pp. 95-103 ◽  
Author(s):  
William R. Holcomb ◽  
Chris Blank
Keyword(s):  
Athletic Training ◽  
Repeated Measures ◽  
Outcome Measure ◽  
Tissue Temperature ◽  
Temperature Elevation ◽  
Main Outcome Measure ◽  
Cooling Period ◽  
Dependent Variables ◽  
Within Subjects ◽  
Independent Variable

Context:Ultrasound significantly raises tissue temperature, but the time of temperature elevation is short.Objective:To assess the effectiveness of superficial preheating on temperature elevation and decline when using ultrasound.Design:Within-subjects design to test the independent variable, treatment condition; repeated-measures ANOVAs to analyze the dependent variables, temperature elevation and decline.Setting:Athletic training laboratory.Intervention:Temperature at a depth of 3.75 cm was measured during ultrasound after superficial heating and with ultrasound alone.Subjects:10 healthy men.Main Outcome Measure:Temperature was recorded every 30 s during 15 min of ultrasound and for 15 min afterward.Results:Temperature elevation with ultrasound was significantly greater with preheating (4.0 ± 0.21 °C) than with ultrasound alone (3.0 ± 0.22 °C). Temperature decline was not significantly different between preheating and ultrasound alone.Conclusions:Superficial preheating significantly increases temperature elevation but has no effect on temperature decline during a 15-min cooling period.

The Effect of Pelvic Position on Popliteal Angle Achieved During 90:90 Hamstring-Length Test

2013 ◽  
Vol 22 (4) ◽  
pp. 254-256 ◽  
Author(s):  
Lee Herrington
Keyword(s):  
Repeated Measures ◽  
Human Performance ◽  
Outcome Measure ◽  
Muscle Length ◽  
Knee Extension ◽  
Hamstring Muscle ◽  
Indirect Measure ◽  
Main Outcome Measure ◽  
Starting Position ◽  
Pelvic Position

Context:Hamstring muscle length is commonly measured because of its perceived relationship to injury of both the hamstrings themselves and the pelvis and lumbar spine. The popliteal (knee-extension) angle measured from the starting position hip and knee at 90° is a commonly used indirect measure of hamstring muscle length. When this measure has been undertaken in the literature previously, little attention was paid to the position of the pelvis, which may significantly influence measurements taken.Design:Repeated-measures.Setting:University human performance laboratory.Participants:60 healthy physically active males (mean age 20.1 ± 1.8 y, range 18–24 y).Intervention:The 2 extremes of pelvic position (anterior and posterior).Main Outcome Measure:Popliteal angle (with maximal knee extension) was measured in 2 positions, 1 of full anterior and 1 of full posterior pelvic tilt.Results:The mean difference in popliteal angle between anterior to posterior pelvic positions was 13.4° ± 9° (range 0–26°); this was statistically significant (P = .0001).Conclusion:The findings of the study indicate that pelvic position has a significant effect on popliteal angle and therefore should be taken into account when measuring hamstring muscle length.

Subcutaneous Tissue Thickness Alters the Effect of NMES

2008 ◽  
Vol 17 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Michael G. Miller ◽  
Christopher C. Cheatham ◽  
William R. Holcomb ◽  
Rosealin Ganschow ◽  
Timothy J. Michael ◽  
...  
Keyword(s):  
Athletic Training ◽  
Outcome Measure ◽  
Subcutaneous Tissue ◽  
Neuromuscular Electrical Stimulation ◽  
Force Production ◽  
Tissue Thickness ◽  
Main Outcome Measure ◽  
Fixed Design ◽  
Post Hoc ◽  
The Relationship

Context:No direct research has been conducted on the relationship between subcutaneous tissue thickness and neuromuscular electrical stimulation (NMES).Objective:The purpose of this study was to determine the effects of subcutaneous tissue thickness on NMES amplitude and NMES force production of the quadriceps.Design:Simple fixed design, testing the independent variable of subcutaneous thickness (skinfold) groups with the dependent variables of NMES amplitude and force production.Setting:Athletic Training Laboratory.Participants:29 healthy women.Intervention:NMES to produce at least 30% of maximal voluntary isometric contractions (MVIC) of the quadriceps.Main Outcome Measure:Maximal NMES amplitude and percentage of MVIC using NMES.Results:A significant skinfold category difference F2,28 = 3.92, P = .032 on NMES amplitude was found. Post hoc revealed the thinnest skinfold category tolerated less amplitude compared to the thickest category. A significant correlation was found between NMES amplitude skinfold category R = .557, P = .002.Conclusion:Higher NMES amplitudes are needed for the thickest skinfold category compared to the thinnest skinfold category.

scholarly journals Short-Term Effects of Suspension Training on Strength and Power Performances

2018 ◽  
Vol 3 (4) ◽  
pp. 51 ◽  
Author(s):  
Giuseppe Giancotti ◽  
Andrea Fusco ◽  
Alice Iannaccone ◽  
Cristina Cortis
Keyword(s):  
Repeated Measures ◽  
Maximum Voluntary Contraction ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
Experimental Session ◽  
Limited Information ◽  
Acute Responses ◽  
Muscle Activations ◽  
The Individual ◽  
Squat Jumps

Suspension Training (ST) workouts include a variety of movements requiring the individual to maintain balance while performing various resistance exercises in an interval fashion. Although ST is thought to elicit higher muscle activations than traditional exercises, only limited information is available on its acute effects on strength and power performances, especially in relation to gender. Therefore, the purpose of this study was to evaluate the strength and power acute responses after ST, also in relation to gender. Eighty-eight (46 males, 42 females) participants were administered countermovement jumps (CMJ), squat jumps (SJ), lower limb Maximum Voluntary Contraction (MVC) at 90° angle knee extension, and grip strength (handgrip) before (PRE) and after (POST) a 50 min ST session involving upper, lower body and core exercises. ANOVA for repeated measures was used to evaluate the differences (p < 0.05) in relation to gender and experimental session. After ST session, significantly higher values emerged in males, whereas no significant changes were found in females. Findings indicate that ST as a form of exercise is useful to maintain and improve acute strength and power performances, especially in male participants. Future studies should be carried out to explore the gender-related differences in response to acute bout of ST exercises.

Vastus Lateralis and Vastus Medialis Obliquus Activity during a Straight-Leg Raise and Knee Extension with Lateral Hip Rotation

2002 ◽  
Vol 11 (2) ◽  
pp. 120-126 ◽  
Author(s):  
Nicole M. Livecchi ◽  
Charles W. Armstrong ◽  
Mitchell L. Cordova ◽  
Mark A. Merrick ◽  
James M. Rankin
Keyword(s):  
Repeated Measures ◽  
Outcome Measure ◽  
Vastus Lateralis ◽  
Knee Extension ◽  
Emg Activity ◽  
Neutral Position ◽  
Vastus Medialis ◽  
Vastus Medialis Obliquus ◽  
Main Outcome Measure ◽  
Straight Leg Raise

Objective:To compare average electromyogram (EMG) activity of the vastus medialis obliquus (VMO) and vastus lateralis (VL) during straight-leg raise (SLR) and knee extension (KE) with the hip in neutral and lateral rotation.Design:1 × 4 factorial repeated-measures.Setting:Laboratory.Participants:13 male college students.Intervention:SLR with hip flexed at 40°, in neutral position, and maximally laterally rotated and KE with hip in neutral and maximally laterally rotated.Main Outcome Measure:Average EMG activity during each of the 4 conditions, normalized against peak muscle activity during that trial.Results:No differences were observed between exercises in VMO activity (F3,36= 0.646,P> .05), VL activity (F3,36= 1.08,P> .05), or VMO:VL ratio (F3,36= 0.598,P> .05).Conclusions:Electrical activity of the VMO or VL and VMO:VL ratio do not change with hip position or exercise.

Voluntary Inducement of Triceps Surae Muscle Cramping

2013 ◽  
Vol 18 (6) ◽  
pp. 40-43 ◽  
Author(s):  
Ashley Goodman ◽  
Kevin A. Zwetsloot
Keyword(s):  
Multiple Testing ◽  
Screening Tool ◽  
Outcome Measure ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Triceps Surae ◽  
Muscle Cramp ◽  
Physically Active ◽  
Main Outcome Measure ◽  
Initial Session

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.

Effect of the Simultaneous Application of NMES and HVPC on Knee Extension Torque

2007 ◽  
Vol 16 (4) ◽  
pp. 307-318 ◽  
Author(s):  
William Holcomb ◽  
Mack D. Rubley ◽  
Tedd J. Girouard
Keyword(s):  
Electrical Stimulation ◽  
Athletic Training ◽  
Outcome Measure ◽  
Peak Torque ◽  
Knee Extension ◽  
Stimulation Protocol ◽  
Simultaneous Application ◽  
Efficient Treatment ◽  
Main Outcome Measure ◽  
Isometric Knee Extension

Context:Electrical stimulation using simultaneous application of two current types for multiple effects is a current treatment option, but the effect of this treatment is not currently known.Objectives:To compare isometric knee extension torque when using neuromuscular electrical stimulation (NMES) in combination with High Voltage Pulsed Current (HVPC) versus NMES alone during three contraction conditions of quadriceps.Design:Counterbalanced, within-subjects design to test independent variables, stimulation protocol, and contraction condition; ANOVA to analyze dependent variable, peak torque.Setting:Athletic Training Research Laboratory. Participants: 14 healthy subjects (7 male and 7 female, age = 21.9 ± 2.0 yr, height = 173.4 ± 10.1cm, weight = 76.1 ± 16.7 kg).Intervention:Participants performed three contraction conditions during two stimulation protocols.Main Outcome Measure:Peak isometric knee extension torque.Results:The main effect for Stimulation Protocol was not significant: F1,26 = .01, P = .94.Conclusion:Simultaneous application of HVPC with NMES does not facilitate the neuromuscular response but may provide an efficient treatment when managing atrophy, strength loss, pain, and edema associated with reconstructive surgery.

The Immediate Effects of Lidocaine Iontophoresis on Trigger-Point Pain

2001 ◽  
Vol 10 (4) ◽  
pp. 287-297 ◽  
Author(s):  
Todd A. Evans ◽  
Jennifer R. Kunkle ◽  
Krista M. Zinz ◽  
Jessica L. Walter ◽  
Craig R. Denegar
Keyword(s):  
Athletic Training ◽  
Repeated Measures ◽  
Outcome Measure ◽  
Trigger Point ◽  
Trigger Points ◽  
Effect Sizes ◽  
Main Outcome Measure ◽  
Pressure Threshold ◽  
Significant Difference ◽  
Normal Current

Objective:To assess the efficacy of lidocaine iontophoresis on myofascial trigger-point pain.Setting:University athletic training facility.Design:Randomized, double-blind, placebo-controlled, repeated-measures.Subjects:Twenty-three subjects with sensitive trigger points over the trapezius.Intervention:Placebo iontophoresis treatment without current or lidocaine, control treatment using distilled water and normal current dose, medicated treatment using 1% lidocaine and normal current dose.Main Outcome Measure:Trigger-point pressure threshold assessed with an algometer.Results:ANOVA revealed a significant difference among treatments (F2,40= 7.38,P< .01). Post hoc comparisons revealed a significant difference in pressure threshold between the lidocaine treatment and the control (P= .01) and placebo (P= .001) treatments. Effect sizes of .28 and .39, respectively, were found for these comparisons.Conclusions:Although the data revealed significant differences between treatments, the small effect sizes and magnitude of the pressure-sensitivity deviation scores suggest that iontophoresis with 1% lidocaine is ineffective in treating trigger points.

scholarly journals Arch-Taping Techniques for Altering Navicular Height and Plantar Pressures During Activity

2015 ◽  
Vol 50 (8) ◽  
pp. 825-832 ◽  
Author(s):  
Tim Newell ◽  
Janet Simon ◽  
Carrie L. Docherty
Keyword(s):  
Athletic Training ◽  
Repeated Measures ◽  
Research Laboratory ◽  
Outcome Measure ◽  
Treadmill Running ◽  
Main Outcome Measure ◽  
Plantar Pressures ◽  
Navicular Drop ◽  
Dependent Variables ◽  
Training Research

Context Arch tapings have been used to support the arch by increasing navicular height. Few researchers have studied navicular height and plantar pressures after physical activity. Objective To determine if taping techniques effectively support the arch during exercise. Design Crossover study. Setting Athletic training research laboratory. Patients or Other Participants Twenty-five individuals (13 men, 12 women; age = 20.0 ± 1.0 years, height = 172.3 ± 6.6 cm, mass = 70.1 ± 10.2 kg) with a navicular drop of more than 8 mm (12.9 ± 3.3 mm) volunteered. Intervention(s) All individuals participated in 3 days of testing, with 1 day for each tape condition: no tape, low dye, and navicular sling. On each testing day, navicular height and plantar pressures were measured at 5 intervals: baseline; posttape; and after 5, 10, and 15 minutes of running. The order of tape condition was counterbalanced. Main Outcome Measure(s) The dependent variables were navicular height in millimeters and plantar pressures in kilopascals. Plantar pressures were divided into 5 regions: medial forefoot, lateral forefoot, lateral midfoot, lateral rearfoot, and medial rearfoot. Separate repeated-measures analyses of variance were conducted for each dependent variable. Results Navicular height was higher immediately after application of the navicular-sling condition (P = .004) but was reduced after 5 minutes of treadmill running (P = .12). We observed no differences from baseline to posttape for navicular height for the low-dye (P = .30) and no-tape conditions (P = .25). Both the low-dye and navicular-sling conditions increased plantar pressures in the lateral midfoot region compared with the no-tape condition. The low-dye condition created decreased pressure in the medial and lateral forefoot regions compared with the no-tape condition. All changes were identified immediately after application and were maintained during running. No changes were noted in plantar pressures for the no-tape condition (P &gt; .05). Conclusions Both taping techniques effectively changed plantar pressures in the lateral midfoot, and these changes were sustained throughout the 15 minutes of exercise.

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