Lack of Effect of Superficial Heat to the Knee on Quadriceps Function in Individuals With Quadriceps Inhibition

2013 ◽  
Vol 22 (2) ◽  
pp. 93-99 ◽  
Author(s):  
Brandon Warner ◽  
Kyung-Min Kim ◽  
Joseph M. Hart ◽  
Susan Saliba
Keyword(s):  
Knee Joint ◽  
Skin Temperature ◽  
Outcome Measures ◽  
Room Temperature ◽  
Knee Extension ◽  
Central Activation Ratio ◽  
Time Points ◽  
Treatment Conditions ◽  
Activation Ratio ◽  
Quadriceps Function

Context:Quadriceps function improves after application of focal joint cooling or transcutaneous electrical nerve stimulation to the knee in patients with arthrogenic muscle inhibition (AMI), yet it is not known whether superficial heat is able to produce a similar effect.Objective:To determine quadriceps function after superficial heat to the knee joint in individuals with AMI.Design:Single blinded randomized crossover.Setting:Laboratory.Patients:12 subjects (4 female, 8 males; 25.6 ± 7.7 y, 177.2 ± 12.7 cm, 78.4 ± 18.2 kg) with a history of knee-joint pathology and AMI, determined with a quadriceps central activation ratio (CAR) of <90%.Intervention:3 treatment conditions for 15 min on separate days: superficial heat using a cervical moist-heat pack (77°C), sham using a cervical moist pack (room temperature at about 24°C), and control (no treatment). All subjects received all treatment conditions in a randomized order.Main Outcome Measures:Central activation ratio and knee-extension torque during maximal voluntary isometric contraction with the knee flexed to 60° were collected at pre, immediately post, 30 min post, and 45 min posttreatment. Skin temperature of the quadriceps and knee and room temperature were also recorded at the same time points.Results:Three (treatment conditions) by 4 (time) repeated ANOVAs found that there were no significant interactions or main effects in either CAR or knee-extension torque (all P > .05). Skin-temperature 1-way ANOVAs revealed that the skin temperature in the knee during superficial heat was significantly higher than other treatment conditions at all time points (P < .05).Conclusions:Superficial heat to the knee joint using a cervical moist-heat pack did not influence quadriceps function in individuals with AMI in the quadriceps.

Quadriceps function in anterior cruciate ligament-deficient knees exercising with transcutaneous electrical nerve stimulation and cryotherapy: a randomized controlled study

2012 ◽  
Vol 26 (11) ◽  
pp. 974-981 ◽  
Author(s):  
Joseph M Hart ◽  
Christopher M Kuenze ◽  
Brian G Pietrosimone ◽  
Christopher D Ingersoll
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Knee Extension ◽  
Exercise Session ◽  
Central Activation ◽  
Central Activation Ratio ◽  
Extension Force ◽  
Activation Ratio ◽  
Anterior Cruciate ◽  
Anterior Cruciate Ligament Deficient

Objective: To compare strength and quadriceps muscle activation in anterior cruciate ligament-deficient patients who underwent a two-week rehabilitation exercise program using TENS or cryotherapy. Design: Randomized, controlled study. Setting: Clinical research laboratory. Subjects: Thirty patients: 20 males, 10 females, 31.6 (13.0) years, 172.8 (10.0) cm, 75.8 (13.0) kg with diagnosed tear of the anterior cruciate ligament. Interventions: All patients attended four sessions of supervised quadriceps strengthening exercises over two weeks, prior to reconstruction surgery. Patients were randomly allocated ( n = 10/group) to receive exercises alone, exercise while wearing a sensory transcutaneous electrical nerve stimulation (TENS) device on the knee joint for the duration of each daily session, or 20 minutes of knee joint cryotherapy immediately prior to each daily exercise session. Main measures: Normalized knee extension force and quadriceps central activation ratio were measured before and after the first supervised treatment session and within 24 hours of the last session. Results: When accounting for differences in baseline measures, there were no statistically significant group differences immediately following the first exercise session for knee extension force ( P = 0.10) or central activation ratio ( P = 0.30) nor were there statistically significant group differences after the two-week intervention for knee extension force ( P = 0.92) or central activation ratio ( P = 0.94). Effect sizes for the change in knee extension force and central activation ratio after two weeks of therapy were all large. Conclusions: Quadriceps strength and central activation in anterior cruciate ligament deficient patients improved after two weeks of rehabilitaiton exercises, however, there were no significant differences between treatment groups.

scholarly journals Reliability of the Superimposed-Burst Technique in Patients With Patellofemoral Pain: A Technical Report

2015 ◽  
Vol 50 (11) ◽  
pp. 1207-1211 ◽  
Author(s):  
Grant E. Norte ◽  
Jamie L. Frye ◽  
Joseph M. Hart
Keyword(s):  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Knee Extension ◽  
Patellofemoral Pain ◽  
Maximal Voluntary Isometric Contraction ◽  
Joint Injury ◽  
Central Activation ◽  
Central Activation Ratio ◽  
Healthy Control ◽  
Activation Ratio

Context  The superimposed-burst (SIB) technique is commonly used to quantify central activation failure after knee-joint injury, but its reliability has not been established in pathologic cohorts. Objective  To assess within-session and between-sessions reliability of the SIB technique in patients with patellofemoral pain. Design  Descriptive laboratory study. Setting  University laboratory. Patients or Other Participants  A total of 10 patients with self-reported patellofemoral pain (1 man, 9 women; age = 24.1 ± 3.8 years, height = 167.8 ± 15.2 cm, mass = 71.6 ± 17.5 kg) and 10 healthy control participants (3 men, 7 women; age = 27.4 ± 5.0 years, height = 173.5 ± 9.9 cm, mass = 78.2 ± 16.5 kg) volunteered. Intervention(s)  Participants were assessed at 6 intervals spanning 21 days. Intraclass correlation coefficients (ICCs [3,3]) were used to assess reliability. Main Outcome Measure(s)  Quadriceps central activation ratio, knee-extension maximal voluntary isometric contraction force, and SIB force. Results  The quadriceps central activation ratio was highly reliable within session (ICC [3,3] = 0.97) and between sessions through day 21 (ICC [3,3] = 0.90–0.95). Acceptable reliability of knee extension (ICC [3,3] = 0.75–0.91) and SIB force (ICC [3,3] = 0.77–0.89) was observed through day 21. Conclusions  The SIB technique was reliable for clinical research up to 21 days in patients with patellofemoral pain.

scholarly journals Pain and Effusion and Quadriceps Activation and Strength

2013 ◽  
Vol 48 (2) ◽  
pp. 186-191 ◽  
Author(s):  
Riann M. Palmieri-Smith ◽  
Mark Villwock ◽  
Brian Downie ◽  
Garin Hecht ◽  
Ron Zernicke
Keyword(s):  
Knee Joint ◽  
Outcome Measure ◽  
Quadriceps Strength ◽  
Joint Effusion ◽  
Joint Injury ◽  
Central Activation Ratio ◽  
Normal Knee ◽  
Knee Joint Injury ◽  
Activation Ratio ◽  
Painful Knee

Context: Quadriceps dysfunction is a common consequence of knee joint injury and disease, yet its causes remain elusive. Objective: To determine the effects of pain on quadriceps strength and activation and to learn if simultaneous pain and knee joint effusion affect the magnitude of quadriceps dysfunction. Design: Crossover study. Setting: University research laboratory. Patients or Other Participants: Fourteen (8 men, 6 women; age = 23.6 ± 4.8 years, height = 170.3 ± 9.16 cm, mass = 72.9 ± 11.84 kg) healthy volunteers. Intervention(s): All participants were tested under 4 randomized conditions: normal knee, effused knee, painful knee, and effused and painful knee. Main Outcome Measure(s): Quadriceps strength (Nm/kg) and activation (central activation ratio) were assessed after each condition was induced. Results: Quadriceps strength and activation were highest under the normal knee condition and differed from the 3 experimental knee conditions (P &lt; .05). No differences were noted among the 3 experimental knee conditions for either variable (P &gt; .05). Conclusions: Both pain and effusion led to quadriceps dysfunction, but the interaction of the 2 stimuli did not increase the magnitude of the strength or activation deficits. Therefore, pain and effusion can be considered equally potent in eliciting quadriceps inhibition. Given that pain and effusion accompany numerous knee conditions, the prevalence of quadriceps dysfunction is likely high.

Focal knee joint cooling increases the quadriceps central activation ratio

2009 ◽  
Vol 27 (8) ◽  
pp. 873-879 ◽  
Author(s):  
Brian G. Pietrosimone ◽  
Christopher D. Ingersoll
Keyword(s):  
Knee Joint ◽  
Central Activation ◽  
Central Activation Ratio ◽  
Activation Ratio

Measurement of Knee-Joint-Position Sense in Women with Genu Recurvatum

2000 ◽  
Vol 9 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Janice K. Loudon
Keyword(s):  
Knee Joint ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Knee Extension ◽  
Position Sense ◽  
Joint Position Sense ◽  
Genu Recurvatum ◽  
The Difference

Context:Proprioception of the knee joint.Objective:To determine the difference in knee-joint-angle reproduction in women with and without genu recurvatum (GR).Design:Between-subjects.Setting:Clinic.Subjects:Twenty-four women divided into 2 groups according to their standing knee-extension angle.Main Outcome Measures:Each subject's ability to actively reproduce active positioning of 3 knee angles (10, 30, and 60°) was measured. Pearson correlation coefficients were calculated to determine correlation values for standing GR angle and absolute angular error (AAE). A1 -way repeated-measures MANOVA was computed to evaluate differences in group, angle, limb, and trial.Results:Standing GR angle correlated significantly to the AAE angle at 10° (r= .48). The high-recurvatum group consistently scored worse, with the highest error rate occurring at 10°.Conclusion:Individuals with GR might have diminished proprioceptive sense at end-range extension that could potentially lead to knee injury.

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

2014 ◽  
Vol 49 (6) ◽  
pp. 740-746 ◽  
Author(s):  
Christopher M. Kuenze ◽  
Jay Hertel ◽  
Joseph M. Hart
Keyword(s):  
Ligament Reconstruction ◽  
Cruciate Ligament ◽  
Knee Extension ◽  
Maximal Voluntary Isometric Contraction ◽  
Men And Women ◽  
Central Activation Ratio ◽  
Continuous Exercise ◽  
History Of ◽  
Activation Ratio ◽  
Anterior Cruciate

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.

Quadriceps and Patient-Reported Function in ACL-Reconstructed Patients: A Principal Component Analysis

2019 ◽  
Vol 28 (1) ◽  
pp. 8-16 ◽  
Author(s):  
Grant E. Norte ◽  
Jay N. Hertel ◽  
Susan A. Saliba ◽  
David R. Diduch ◽  
Joseph M. Hart
Keyword(s):  
Muscle Function ◽  
Knee Extensor ◽  
Principal Component ◽  
Motor Threshold ◽  
Central Activation ◽  
Central Activation Ratio ◽  
Active Motor ◽  
Total Knee ◽  
Activation Ratio ◽  
Quadriceps Function

Context: Assessment of physical function for individuals after anterior cruciate ligament reconstruction (ACL-R) is complex and warrants the use of diverse evaluation strategies. To maximize the efficiency of assessment, there is a need to identify tests that provide the most meaningful information about this population. Objective: To investigate underlying constructs of quadriceps muscle function that uniquely describe aspects of performance in patients after ACL-R and establish clinical thresholds for measures able to classify patients with and without ACL-R. Design: Cross-sectional. Setting: Research laboratory. Patients (or Other Participants): Seventy-two patients with a primary, unilateral ACL-R (32 males and 40 females, age = 26.0 [9.3] y, time since surgery = 46.5 [58.0] mo) and 30 healthy controls (12 males and 18 females, age = 22.7 [4.6] y). Intervention(s): Quadriceps function was assessed bilaterally during 1 study visit. Main Outcome Measures: Isokinetic strength (peak torque, total work, and average power) at 90° and 180°/s, maximal voluntary isometric contraction torque, fatigue index, central activation ratio, Hoffmann reflex, and active motor threshold. Principal component analyses were performed for the involved limb, contralateral limb, and limb symmetry. Receiver–operator characteristic curve analyses were conducted to determine the diagnostic utility of each variable. Binary logistic regression was used to predict group membership (ACL-R vs healthy). Results: Three components of peripheral, central, and combined (peripheral and central) muscle function were identified, explaining 70.7% to 80.5% of variance among measures of quadriceps function. Total knee-extensor work at 90°/s (≥18.4 J/kg), active motor threshold (≥39.5%), and central activation ratio (≥94.7%) of the involved limb were strong predictors of patient status and correctly classified 83.5% of patients with ACL-R (P < .001). Conclusions: Unique constructs of peripheral, central, and combined muscle function exist in patients with ACL-R. Total knee-extensor work at 90°/s, active motor threshold, and central activation ratio consistently explained a significant portion of variance in measures of quadriceps function, demonstrated acceptable to excellent diagnostic utility, and predicted group membership with 72.8% to 83.5% accuracy.

Investigation of Plasma Treatment Conditions for Wafer-Scale Room-Temperature Bonding Using Ultrathin Au Films in Ambient Air

2019 ◽  
Vol 139 (7) ◽  
pp. 217-218
Author(s):  
Michitaka Yamamoto ◽  
Takashi Matsumae ◽  
Yuichi Kurashima ◽  
Hideki Takagi ◽  
Tadatomo Suga ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Room Temperature ◽  
Ambient Air ◽  
Wafer Scale ◽  
Treatment Conditions

scholarly journals Passive knee exoskeletons in functional tasks: Biomechanical effects of a SpringExo coil-spring on squats

2021 ◽  
Vol 2 ◽  
Author(s):  
Rand Hidayah ◽  
Dongbao Sui ◽  
Kennedi A. Wade ◽  
Biing-Chwen Chang ◽  
Sunil Agrawal
Keyword(s):  
Outcome Measures ◽  
Muscle Activation ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Lower Limbs ◽  
Flexion Angle ◽  
Coil Spring ◽  
Foot Pressure ◽  
Low Profile ◽  
Muscle Activations

Abstract Passive wearable exoskeletons are desirable as they can provide assistance during user movements while still maintaining a simple and low-profile design. These can be useful in industrial tasks where an ergonomic device could aid in load lifting without inconveniencing them and reducing fatigue and stress in the lower limbs. The SpringExo is a coil-spring design that aids in knee extension. In this paper, we describe the muscle activation of the knee flexors and extensors from seven healthy participants during repeated squats. The outcome measures are the timings of the key events during squat, flexion angle, muscle activation of rectus femoris and bicep femoris, and foot pressure characteristics of the participants. These outcome measures assess the possible effects of the device during lifting operations where reduced effort in the muscles is desired during ascent phase of the squat, without changing the knee and foot kinematics. The results show that the SpringExo significantly decreased rectus femoris activation during ascent (−2%) without significantly affecting either the bicep femoris or rectus femoris muscle activations in descent. This implies that the user could perform a descent without added effort and ascent with reduced effort. The exoskeleton showed other effects on the biomechanics of the user, increasing average squat time (+0.02 s) and maximum squat time (+0.1 s), and decreasing average knee flexion angle (−4°). The exoskeleton has no effect on foot loading or placement, that is, the user did not have to revise their stance while using the device.

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