Vastus Medialis Activation during Knee Extension Exercises: Evidence for Exercise Prescription

2008 ◽  
Vol 17 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Lori A. Bolgla ◽  
Scott W. Shaffer ◽  
Terry R. Malone
Keyword(s):  
Outcome Measures ◽  
Repeated Measures ◽  
Exercise Prescription ◽  
Weight Bearing ◽  
Knee Extension ◽  
Important Indicator ◽  
Maximum Voluntary Isometric Contraction ◽  
Repeated Measures Design ◽  
Knee Rehabilitation ◽  
Straight Leg Raise

Context:Knee extension exercise is an important part of knee rehabilitation. Clinicians prescribe non-weight bearing exercise initially and progress patients to weight bearing exercise once they can perform a straight leg raise (SLR).Objective:Compare VM activation during a SLR and weight bearing exercises.Design:One-way repeated measures design.Setting:University Laboratory.Subjects:Fifteen healthy subjects.Intervention:One SLR exercise and 6 weight-bearing knee extension exercises.Main Outcome Measures:Electromyographic amplitudes for the VM expressed as a percent maximum voluntary isometric contraction.Results:The SLR had greater activation than the single leg stance and bilateral squat exercises. The step-up and unilateral leg press exercises had the greatest activation.Conclusions:SLR performance can be an important indicator for exercise progression. These results provide foundational knowledge to assist clinicians with exercise prescription.

scholarly journals Exploring the effect of pelvic belt configurations upon athletic lumbopelvic pain

2012 ◽  
Vol 37 (2) ◽  
pp. 124-131 ◽  
Author(s):  
Leanne Sawle ◽  
Jennifer Freeman ◽  
Jonathan Marsden ◽  
Martin John Matthews
Keyword(s):  
Outcome Measures ◽  
Study Design ◽  
Repeated Measures ◽  
Clinical Relevance ◽  
Return To Sport ◽  
Repeated Measures Anova ◽  
Repeated Measures Design ◽  
New Approaches ◽  
And Function ◽  
Straight Leg Raise

Background: Lumbopelvic injuries are often refractory to treatment and can limit return to sport. Research shows that 50 Newtons (N) of force applied transversely to the pelvis improves lumbopelvic stability and pain. This study applies transverse and diagonal forces to the pelvis in athletes with lumbopelvic pain, and investigates effects on pain and function. Objective: To investigate the effects of transverse and diagonal compressive forces applied to the pelvis of athletes with lumbopelvic pain Study Design: A randomized, repeated measures design using 20 athletes with lumbopelvic pain. Methods: No belt and four pelvic belt configurations (50 N force) were tested. Outcome measures were: resting pain, pain on active straight leg raise (ASLR), resisted hip adduction force and pain on 1-metre broad jump. Force on the adduction test was determined via load cell. Results: Data were analyzed using repeated measures ANOVA. Squeeze test showed significant effect of condition F (4, 76) = 2.7, P < 0.05. On ASLR ipsilateral to the side of pain, pain decreased across conditions ( F (4, 76) = 2.5 P = 0.05). Conclusion: Results suggest application of diagonal forces towards the site of pain may have additional benefits in improving pain and function. Such information may inform the development of an orthosis. Clinical relevance The results may be used clinically to determine the effectiveness of different belt placements (with belts or straps) in managing athletic lumbopelvic pain. The results offer an alternative to the application of transverse belts, and may inform new approaches in the development of orthotics.

Tibiofemoral Joint-Surface Motions in Weight-Bearing and Non-Weight-Bearing Movement

2003 ◽  
Vol 12 (2) ◽  
pp. 143-161 ◽  
Author(s):  
John H. Hollman ◽  
Robert H. Deusinger ◽  
Linda R. Van Dillen ◽  
Dequan Zou ◽  
Scott D. Minor ◽  
...  
Keyword(s):  
Outcome Measures ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Weight Bearing ◽  
Knee Extension ◽  
Thigh Muscle ◽  
Joint Surface ◽  
Emg Activity ◽  
Sliding Motion ◽  
Type Design

Context:Analyses of the path of instant center of rotation (PICR) can be used to infer joint-surface rolling and sliding motion (arthrokinematics). Previous PICR research has not quantified arthrokinematics during weight-bearing (WB) movement conditions or studied the association of muscle activity with arthrokinematics.Objective:To examine tibiofemoral arthrokinematics and thigh-muscle EMG during WB and non-weight-bearing (NWB) movement.Design:2 x 9 repeated-measures experiment.Setting:Laboratory.Participants:11 healthy adults (mean age 24 years).Main Outcome Measures:Tibiofemoral percentage rolling arthrokinematics and quadriceps: hamstring EMG activity.Results:WB percentage rolling (76.0% ± 4.7%) exceeded that of NWB (57.5% ± 1.8%) through terminal knee extension (F8,80= 8.99,P< .001). Quadriceps:hamstring EMG ratios accounted for 45.1% and 34.7% of the variance in arthrokinematics throughout the WB and NWB movement conditions, respectively (P< .001).Conclusions:More joint-surface rolling occurs through terminal knee extension during WB movement and is associated with an increase in hamstring activity.

Electromyographic Evaluation of Abdominal-Muscle Function With and Without Concomitant Pelvic-Floor-Muscle Contraction

2013 ◽  
Vol 22 (2) ◽  
pp. 108-114 ◽  
Author(s):  
Nahid Tahan ◽  
Amir Massoud Arab ◽  
Bita Vaseghi ◽  
Khosro Khademi
Keyword(s):  
Pelvic Floor ◽  
Muscle Contraction ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Pelvic Floor Muscle ◽  
Abdominal Muscle ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
Repeated Measures Design ◽  
Emg Signal

Context:Coactivation of abdominal and pelvic-floor muscles (PFM) is an issue considered by researchers recently. Electromyography (EMG) studies have shown that the abdominal-muscle activity is a normal response to PFM activity, and increase in EMG activity of the PFM concomitant with abdominal-muscle contraction was also reported.Objective:The purpose of this study was to compare the changes in EMG activity of the deep abdominal muscles during abdominal-muscle contraction (abdominal hollowing and bracing) with and without concomitant PFM contraction in healthy and low-back-pain (LBP) subjects.Design:A 2 × 2 repeated-measures design.Setting:Laboratory.Participants:30 subjects (15 with LBP, 15 without LBP).Main Outcome Measures:Peak rectified EMG of abdominal muscles.Results:No difference in EMG of abdominal muscles with and without concomitant PFM contraction in abdominal hollowing (P = .84) and abdominal bracing (P = .53). No difference in EMG signal of abdominal muscles with and without PFM contraction between LBP and healthy subjects in both abdominal hollowing (P = .88) and abdominal bracing (P = .98) maneuvers.Conclusion:Adding PFM contraction had no significant effect on abdominal-muscle contraction in subjects with and without LBP.

Influence of Foot Type and Orthotics on Static and Dynamic Postural Control

2004 ◽  
Vol 13 (1) ◽  
pp. 54-66 ◽  
Author(s):  
Lauren C. Olmsted ◽  
Jay Hertel
Keyword(s):  
Postural Control ◽  
Athletic Training ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Center Of Pressure ◽  
Group Interaction ◽  
Force Plate ◽  
Balance Test ◽  
Repeated Measures Design ◽  
Plate Dynamic

Context:The effects of custom-molded foot orthotics on neuromuscular processes are not clearly understood.Objective:To examine these effects on postural control in subjects with different foot types.Design:Between-groups, repeated-measures design.Setting:Athletic training laboratory.Subjects:30 healthy subjects assigned to groups by foot type: planus (n = 11), rectus (n = 12), or cavus (n = 7).Interventions:Custom-fit semirigid orthotics.Main Outcome Measures:Static postural control was measured on a force plate. Dynamic postural control was measured using the Star Excursion Balance Test. Both measurements were assessed with and without orthotics at baseline and 2 weeks later.Results:For static postural control, a significant condition-by-group interaction was found. Subjects with cavus feet had a decreased center-of-pressure velocity while wearing orthotics. For dynamic postural control, a significant condition-by-direction-by-group interaction was found. Subjects with cavus feet had increased reach distances in 3 of 8 directions while wearing orthotics.Conclusions:Custom orthotics were associated with some improvements in static and dynamic postural control in subjects with cavus feet.

Temporal Influences of Functional Knee Bracing on Torque Production of the Lower Extremity

2006 ◽  
Vol 15 (3) ◽  
pp. 215-227
Author(s):  
Brian Campbell ◽  
James Yaggie ◽  
Daniel Cipriani
Keyword(s):  
Lower Extremity ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Exercise Intervention ◽  
Three Dimensional ◽  
Exercise Program ◽  
Joint Moments ◽  
Repeated Measures Design ◽  
Reaction Forces ◽  
Vertical Ground Reaction Forces

Context:Functional knee braces (FKB) are used prophylactically and in rehabilitation to aide in the functional stability of the knee.Objective:To determine if alterations in select lower extremity moments persist throughout a one hour period in healthy individuals.Design:2X5 repeated measures design.Setting:Biomechanics Laboratory.Subjects:Twenty subjects (14 male and 6 female, mean age 26.5±7 yrs; height 172.4±13 cm; weight 78.6±9 kg), separated into braced (B) and no brace (NB) groups.Intervention:A one-hour exercise program divided into three 20 minute increments.Main Outcome Measures:Synchronized three-dimensional kinematic and kinetic data were collected at 20-minute increments to assess the effect of the FKB on select lower extremity moments and vertical ground reaction forces.Results:Increase in hip moment and a decrease in knee moment were noted immediately after brace application and appeared to persist throughout a one hour bout of exercise.Conclusions:The FKB and the exercise intervention caused decreases in knee joint moments and increases in hip joint moments.

Comparisons of Static and Dynamic Balance Following Training in Aquatic and Land Environments

2006 ◽  
Vol 15 (4) ◽  
pp. 299-311 ◽  
Author(s):  
Aimee E. Roth ◽  
Michael G. Miller ◽  
Marc Ricard ◽  
Donna Ritenour ◽  
Brenda L. Chapman
Keyword(s):  
Outcome Measures ◽  
Repeated Measures ◽  
Dynamic Balance ◽  
Balance Training ◽  
Aquatic Environments ◽  
Repeated Measures Design ◽  
Time Interaction ◽  
Type Design ◽  
Post Test

Context:It has been theorized that aquatic balance training differs from land balance training.Objective:To compare the effects of balance training in aquatic and land environments.Design:Between-groups, repeated-measures design.Setting:Biomechanics laboratory and pool.Participants:24 healthy subjects randomly assigned to aquatic (n = 8), land (n = 10), or control (n = 6) groups.Intervention:Four weeks of balance training.Main Outcome Measures:Balance was measured (pre, mid, post, follow-up). COP variables: radial area, y range, x range in single leg (SL), tandem (T), single leg foam (SLF), and tandem form (TF) stance.Results:A significant condition × time interaction for x range was found, with improvements for SL, SLF, and TF. Radial area improved, with post-test 1.01 ± .23 cm2and follow-up 1.06 ± .18 cm2significantly lower than pretest 1.18 ± .23 cm2. Y range significantly improved, with posttest (4.69 ± 1.02 cm2) lower than pretest (5.89 ± 1.26 cm2). The foam conditions (SLF & TF) were significantly different from non-foam conditions (SL & T) for all variables.Conclusions:Results of this study show that balance training can effectively be performed in both land and aquatic environments.

Differences in Static- and Dynamic-Balance Task Performance After 4 Weeks of Intrinsic-Foot-Muscle Training: The Short-Foot Exercise Versus the Towel-Curl Exercise

2012 ◽  
Vol 21 (4) ◽  
pp. 327-333 ◽  
Author(s):  
Scott K. Lynn ◽  
Ricardo A. Padilla ◽  
Kavin K.W. Tsang
Keyword(s):  
Task Performance ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Mixed Model ◽  
Center Of Pressure ◽  
Dynamic Balance ◽  
Weight Bearing ◽  
Static Balance ◽  
Balance Test ◽  
Balance Task

Context:Proper functioning of the intrinsic foot musculature (IFM) is essential in maintaining the integrity of the medial longitudinal arch (MLA). Improper functioning of the IFM leads to excessive pronation of the foot, which has been linked to various pathologies. Therefore, training the IFM to avoid excessive pronation may help prevent some of these pathologies; however, it is not clear how to train these muscles optimally.Objective:To investigate the effects of 2 different types of IFM training on the height of the MLA and static- and dynamic-balance task performance.Design:Randomized controlled trial, repeated-measures mixed-model design.Setting:University biomechanics laboratory for testing and a home-based training program.Participants:24 healthy, university-age volunteers (3 groups of 8) with no history of major lower limb pathology or balance impairment.Interventions:One experimental group performed 4 wk of the short-foot exercise (SFE) and the other performed 4 wk of the towel-curl exercise (TCE). Participants were asked to perform 100 repetitions of their exercise per day.Main Outcome Measures:Navicular height during weight bearing, the total range of movement of the center of pressure (COP) in the mediolateral (ML) direction for a static-balance test and a dynamic-balance test.Results:There were no differences in the navicular height or static-balance tests. For the dynamic-balance test, all groups decreased the ML COP movement on the dominant limb by a small amount (~5 mm); however, the SFE group was able to decrease COP movement much more than the TCE group in the nondominant limb.Conclusions:The SFE appeared to train the IFM more effectively than the TCE; however, there were differing results between the dominant and nondominant legs. These imbalances need to be taken into consideration by clinicians.

Knee-Extension Exercise’s Lack of Immediate Effect on Maximal Voluntary Quadriceps Torque and Activation in Individuals With Anterior Knee Pain

2012 ◽  
Vol 21 (2) ◽  
pp. 119-126 ◽  
Author(s):  
Jihong Park ◽  
Terry L. Grindstaff ◽  
Joe M. Hart ◽  
Jay N. Hertel ◽  
Christopher D. Ingersoll
Keyword(s):  
Outcome Measures ◽  
Knee Pain ◽  
Anterior Knee Pain ◽  
Controlled Trial ◽  
Weight Bearing ◽  
Knee Extension ◽  
Maximal Voluntary Isometric Contraction ◽  
Acute Changes ◽  
Knee Extension Exercise ◽  
Anterior Knee

Context:Weight-bearing (WB) and non-weight-bearing (NWB) exercises are commonly used in rehabilitation programs for patients with anterior knee pain (AKP).Objective:To determine the immediate effects of isolated WB or NWB knee-extension exercises on quadriceps torque output and activation in individuals with AKP.Design:A single-blind randomized controlled trial.Setting:Laboratory.Participants:30 subjects with self-reported AKP.Interventions:Subjects performed a maximal voluntary isometric contraction (MVIC) of the quadriceps (knee at 90°). Maximal voluntary quadriceps activation was quantified using the central activation ratio (CAR): CAR = MVIC/(MVIC + superimposed burst torque). After baseline testing, subjects were randomized to 1 of 3 intervention groups: WB knee extension, NWB knee extension, or control. WB knee-extension exercise was performed as a sling-based exercise, and NWB knee-extension exercise was performed on the Biodex dynamometer. Exercises were performed in 3 sets of 5 repetitions at approximately 55% MVIC. Measurements were obtained at 4 times: baseline and immediately and 15 and 30 min postexercise.Main Outcome Measures:Quadriceps torque output (MVIC: N·m/Kg) and quadriceps activation (CAR).Results:No significant differences in the maximal voluntary quadriceps torque output (F2,27 = 0.592, P = .56) or activation (F2,27 = 0.069, P = .93) were observed among the 3 treatment groups.Conclusions:WB and NWB knee-extension exercises did not acutely change quadriceps torque output or activation. It may be necessary to perform exercises over a number of sessions and incorporate other disinhibitory interventions (eg, cryotherapy) to observe acute changes in quadriceps torque and activation.

Insulin-Sensitivity Response to a Single Bout of Resistive Exercise in Type 1 Diabetes Mellitus

2009 ◽  
Vol 18 (4) ◽  
pp. 564-571 ◽  
Author(s):  
Carolyn Jimenez ◽  
Mayra Santiago ◽  
Michael Sitler ◽  
Guenther Boden ◽  
Carol Homko
Keyword(s):  
Type 1 Diabetes ◽  
Insulin Sensitivity ◽  
Resistance Exercise ◽  
Outcome Measures ◽  
Repeated Measures ◽  
University Hospital ◽  
Control Group ◽  
Repeated Measures Design ◽  
Single Bout

Context:Little is known about the acute effects of resistance exercise on insulin sensitivity in people with type 1 diabetes.Design:Repeated-measures design with 2 independent variables: group (exercise and nonexercise control) and time (preexercise and 12 and 36 h postexercise).Setting:General Clinical Research Center, Temple University Hospital, Philadelphia, PA.Patients:14 physically active subjects (11 men and 3 women) with type 1 diabetes.Intervention:The exercise group completed 5 sets of 6 repetitions of strenuous (80% 1-RM) quadriceps and hamstring exercises while the control group performed only activities of daily Living.Main Outcome Measures:Insulin sensitivity was assessed with the euglycemic-hyperinsulinemic-clamp technique preexercise and 12 and 36 h postexercise.Results:Insulin-sensitivity values were not significantly different between the exercise and control groups (P = .92) or over time (P = .67).Conclusions:A single bout of strenuous resistance exercise does not alter insulin sensitivity in people with type 1 diabetes.

Effect of Humeral-Elevation Angle on Electromyographic Activity in the Serratus Anterior During the Push-Up-Plus Exercise

2017 ◽  
Vol 26 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Ui-jae Hwang ◽  
Oh-yun Kwon ◽  
In-cheol Jeon ◽  
Si-hyun Kim ◽  
Jong-hyuck Weon
Keyword(s):  
Outcome Measures ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Elevation Angle ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Serratus Anterior ◽  
Repeated Measures Design ◽  
Activity Ratios ◽  
Push Up

Context:The push-up-plus (PP) exercise has been recommended for strengthening of the serratus anterior (SA). Previous studies have investigated the effect of different stability properties of the base of support to adjust the difficulty level of SA muscle-strengthening exercises in the PP position. However, the optimal humeral-elevation angle (HEA) for selective activation and maximum contraction of the SA during PP has not been investigated.Objectives:To assess the effects of HEA during PP on electromyographic (EMG) activity in the SA, upper trapezius (UT), and pectoralis major (PM) and on the UT:SA and PM:SA activity ratios.Design:Comparative, repeated-measures design.Setting:University research laboratory.Participants:29 healthy men.Main Outcome Measures:The subjects performed PP at 3 different HEAs (60°, 90°, and 120°); EMG activity in the SA, UT, and PM was measured, and the UT:SA and PM:SA activity ratios were calculated. Differences in muscle activity and ratios between the 60°, 90°, and 120° HEAs were assessed using 1-way repeated-measures analysis of variance; the Bonferroni correction was applied.Results:SA muscle activity was significantly increased, in order of magnitude, at the 120°, 90°, and 60° HEAs. UT:SA and PM:SA activity ratios were significantly greater during performance of the PP at an HEA of 60° than at HEAs of 120° and 90°.Conclusion:The results suggest that an HEA of 120° should be used during performance of the PP because it produces greater SA activation than HEAs of 60° and 90°.

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