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.

scholarly journals Knee Joint Movements in Subjects Without Knee Pathology and Subjects With Injured Anterior Cruciate Ligaments

2002 ◽  
Vol 82 (10) ◽  
pp. 960-972 ◽  
Author(s):  
John H Hollman ◽  
Robert H Deusinger ◽  
Linda R Van Dillen ◽  
Matthew J Matava
Keyword(s):  
Knee Joint ◽  
Muscle Activity ◽  
Mixed Model ◽  
Weight Bearing ◽  
Knee Extension ◽  
Joint Surface ◽  
Emg Activity ◽  
Hamstring Muscle ◽  
Anterior Cruciate ◽  
Knee Pathology

Abstract Background and Purpose. Although weight-bearing (WB) exercise and increased hamstring muscle activity may contribute to knee joint stability in knees with an injured anterior cruciate ligament (ACL), the relationship among ACL integrity, muscle activity, and joint surface motion is not fully understood. The purpose of this study was to investigate whether knee joint rolling and gliding movements and electromyographic (EMG) activity differed between subjects with injured ACLs and subjects without knee pathology. Subjects. Fifteen subjects with injured ACLs (9 men and 6 women; mean age=26 years, SD=7, range=18–36) and 15 age- and sex-matched subjects without knee pathology (9 men and 6 women; mean age=25 years, SD=6, range=18–36) participated in the study. Methods. Sagittal-plane knee joint rolling and gliding movements and lower-extremity EMG activity were measured during non-weight-bearing (NWB) and WB movements. Mixed-model analyses of variance were conducted to analyze rolling and gliding and EMG data. Results. During NWB knee extension, greater joint surface gliding occurred in knees with injured ACLs at full knee extension. During WB knee extension, greater gliding occurred in knees with injured ACLs throughout the range of motion tested. No differences in EMG activity occurred between groups. Discussion and Conclusion. The results suggest that, in the absence of increased hamstring muscle activity, anterior tibial displacement is not reduced in knees with injured ACLs during WB movement.

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°.

Weight-Bearing and Non-Weight-Bearing Knee-Joint Reposition Sense and Functional Performance

2003 ◽  
Vol 12 (1) ◽  
pp. 54-66 ◽  
Author(s):  
Joshua M. Drouin ◽  
Peggy A. Houglum ◽  
David H. Perrin ◽  
Bruce M. Gansneder
Keyword(s):  
Outcome Measures ◽  
Repeated Measures ◽  
Functional Performance ◽  
Weight Bearing ◽  
Activity Level ◽  
Repeated Measures Anova ◽  
Type Design ◽  
Hop Test ◽  
The Relationship ◽  
Pearson Correlations

Objective:To determine the relationship between weight-bearing (WB) and non-weight-bearing (NWB) joint reposition sense (JRS) and a functional hop test (FH) and to compare performance on these parameters between athletes and nonathletes.Design:Repeated-measures ANOVA and Pearson correlations.Setting:Research laboratory.Participants:40 men (age = 20.8 ± 1.7 y; ht = 176.9 ± 5.8 cm; wt = 82.6 ± 9.5 kg): 20 lacrosse players and 20 nonathletes.Main Outcome Measures:Ability to actively reproduce 30° of knee flexion in the WB and NWB conditions and functional performance on a single-leg crossover-hop test.Results:No significant correlations were observed between JRS and FH in athletes and nonathletes. No significant differences were observed between athletes and nonathletes in JRS. All participants were significantly more accurate at WB than at NWB JRS.Conclusions:There appears to be no relationship between WB or NWB JRS and functional performance, regardless of one’s physical activity level

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.

Functional Effects of Inertial Training of the Upper Extremity

2003 ◽  
Vol 12 (3) ◽  
pp. 229-239 ◽  
Author(s):  
Todd A. McLoda ◽  
Kate M. Murphy ◽  
Steve Davison
Keyword(s):  
Upper Extremity ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Biceps Brachii ◽  
Exercise Group ◽  
Emg Activity ◽  
Control Group ◽  
Significant Group ◽  
Time Interaction ◽  
Size Groups

Context:Inertial training of the shoulder.Objective:To determine the differences of functional and EMG measures between a control group and an exercise group of overhead throwers.Design:Repeated measures.Setting:Research laboratory.Participants:17 intercollegiate baseball players and 19 intercollegiate softball players divided into 2 equal-size groups, control and exercise.Main Outcome Measures:Preliminary data were recorded, including throwing velocity, throwing accuracy, and EMG activity of the biceps brachii, upper pectorals, and posterior deltoid. The exercise group completed a 4-week training regimen on the Impulse Inertial Trainer. All participants returned for follow-up measures.Results:No significant group-by-time interaction occurred relative to ball velocity, accuracy, or EMG activity.Conclusion:For experienced throwers, functional measures and muscle activity during throwing were not affected by inertial training of the upper extremity.

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.

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.

Difference in Ratio of Evertor to Invertor Activity Between the Dominant and Nondominant Legs During Simulated Lateral Ankle Sprain

2013 ◽  
Vol 22 (4) ◽  
pp. 272-278 ◽  
Author(s):  
Adam C. Knight ◽  
Wendi H. Weimar
Keyword(s):  
Outcome Measures ◽  
Ankle Sprain ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Previous History ◽  
Physically Active ◽  
Lateral Ankle ◽  
History Of ◽  
University Laboratory

Context:The dominant and nondominant legs respond asymmetrically during landing tasks, and this difference may occur during an inversion perturbation and provide insight into the role of ankle-evertor and -invertor muscle activity.Objective:To determine if there is a difference in the ratio of evertor to invertor activity between the dominant and nondominant legs and outer-sole conditions when the ankle is forced into inversion.Design:Repeated-measures single-group design.Setting:University laboratory.Participants:15 physically active healthy volunteers with no previous history of an ankle sprain or lower extremity surgery or fracture.Interventions:An outer sole with fulcrum was used to cause 25° of inversion at the subtalar joint after landing from a 27-cm step-down task. Participants performed 10 fulcrum trials on both the dominant and nondominant leg.Main Outcome Measures:The ratio of evertor to invertor muscle activity 200 ms before and 200 ms after the inversion perturbation was measured using electromyography. This ratio was the dependent variable. Independent variables included outer-sole condition (fulcrum, flat), leg (dominant, nondominant), and time (prelanding, postlanding). The data were analyzed with separate 2-way repeated-measures ANOVA, 1 for the prelanding ratios and 1 for the postlanding ratios.Results:For the postlanding ratios, the fulcrum outer sole had a significantly greater (P < .05) ratio than the flat outer sole, and the nondominant leg had a significantly greater (P < .05) ratio than the dominant leg.Conclusions:These results indicate that a greater evertor response is produced when the ankle is forced into inversion, and a greater response is produced for the nondominant leg, which may function better during a postural-stabilizing task than the dominant leg.

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.

Hip- and Thigh-Muscle Activation During the Star Excursion Balance Test

2011 ◽  
Vol 20 (4) ◽  
pp. 428-441 ◽  
Author(s):  
Beth Norris ◽  
Elaine Trudelle-Jackson
Keyword(s):  
Outcome Measures ◽  
Repeated Measures ◽  
Muscle Activation ◽  
Neuromuscular Control ◽  
Repeated Measure ◽  
Thigh Muscle ◽  
Balance Test ◽  
Retest Reliability ◽  
Star Excursion Balance Test ◽  
Test Retest Reliability

Context:The Star Excursion Balance Test (SEBT) is often used to train and assess dynamic balance and neuromuscular control. Few studies have examined hip- and thigh-muscle activation during the SEBT.Objective:To quantify hip- and thigh-muscle activity during the SEBT.Design:Repeated measures.Setting:Laboratory.Participants:22 healthy individuals, 11 men and 11 women.Methods:EMG measurements were taken as participants completed 3 trials of the anterior (A), medial (M), and posteromedial (PM) reach directions of the SEBT.Main Outcome Measures:Mean EMG data (% maximal voluntary isometric contraction) from the gluteus medius (Gmed), gluteus maximus (Gmax), and vastus medialis (VM) were measured during the eccentric phase of each SEBT reach direction. Test–retest reliability of EMG data across the 3 trials in each direction was calculated. EMG data from each muscle were compared across the 3 reach directions.Results:Test–retest reliability ranged from ICC3,1 values of .91 to .99. A 2-way repeated-measure ANOVA revealed a significant interaction between muscle activation and reach direction. One-way ANOVAs showed no difference in GMed activity between the A and M directions. GMed activity in the A and M directions was greater than in the PM direction. There was no difference in GMax and VM activity across the 3 directions.Conclusion:GMed was recruited most effectively when reaching was performed in the A and M directions. The A, M, and PM directions elicited similar patterns of muscle recruitment for the GMax and VM. During all 3 SEBT directions, VM activation exceeded the 40–60% threshold suggested for strengthening effects. GMed activity also exceeded the threshold in the M direction. GMax activation, however, was below the 40% threshold for all 3 reach directions, suggesting that performing dynamic lower extremity reaching in the A, M, and PM directions may not elicit strengthening effects for the GMax.

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