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.

Central Activation Ratio Is a Reliable Measure for Gluteal Neuromuscular Function

2020 ◽  
Vol 29 (7) ◽  
pp. 956-962
Author(s):  
Daniel Gilfeather ◽  
Grant Norte ◽  
Christopher D. Ingersoll ◽  
Neal R. Glaviano
Keyword(s):  
Isometric Contraction ◽  
Outcome Measure ◽  
Intraclass Correlation ◽  
Neuromuscular Function ◽  
Healthy Population ◽  
Maximal Voluntary Isometric Contraction ◽  
Central Activation ◽  
Central Activation Ratio ◽  
Hip Abduction ◽  
Activation Ratio

Context: Central activation ratio (CAR) is a common outcome measure used to quantify gross neuromuscular function of the quadriceps using the superimposed burst technique, yet this outcome measure has not been validated in the gluteal musculature. Objective: To quantify gluteus medius (GMed) and gluteus maximus (GMax) CAR in a healthy population and evaluate its validity and reliability over a 1-week period. Design: Descriptive. Setting: Laboratory. Patients or Other Participants: A total of 20 healthy participants (9 males and 11 females; age 22.2 [1.4] y, height 173.4 [11.1] cm, mass 84.8 [25.8] kg) were enrolled in this study. Interventions: Participants were assessed at 2 sessions, separated by 1 week. Progressive electrical stimuli (25%, 50%, 75%, and 100%) were delivered to the GMed and GMax at rest, and 100% stimuli were delivered during progressive hip abduction and extension contractions (25%, 50%, 75%, and 100% maximal voluntary isometric contraction). Main Outcome Measures: GMed and GMax CAR, and hip abduction and hip extension maximal voluntary isometric contraction torque. Line of best fit and coefficient of determination (r2) were used to assess the relationship between torque output and CAR at varying levels of stimuli. Intraclass correlation coefficients, ICCs(3,k), were used to assess the between-session reliability. Results: GMed CAR was 96.1% (3.4%) and 96.6% (3.2%), on visits 1 and 2, respectively, whereas GMax CAR was 86.5% (7.5%) and 87.2% (10.7%) over the 2 sessions. A third-order polynomial demonstrated the best line of fit between varying superimposed burst intensities at rest for both GMed (r2 = .156) and GMax (r2 = .602). Linear relationships were observed in the CAR during progressive contractions with a maximal superimposed burst, GMed (r2 = .409) and GMax (r2 = .639). Between-session reliability was excellent for GMed CAR, ICC(3,k) = .911, and moderate for GMax CAR, ICC(3,k) = .704. Conclusion: CAR appears to be an acceptable measure of GMed and GMax neuromuscular function in healthy individuals. Gluteal CAR measurements are reliable measures over a 1-week test period.

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 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.

Influence of Handgrip Stabilization During Isokinetic Knee Strength Assessment in Older Women

2020 ◽  
Vol 127 (4) ◽  
pp. 671-683
Author(s):  
João P. Nunes ◽  
Paolo M. Cunha ◽  
Jerry L. Mayhew ◽  
Alex S. Ribeiro ◽  
Paulo S. Junior ◽  
...  
Keyword(s):  
Older Women ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Knee Extension ◽  
Convenience Sample ◽  
Strength Assessment ◽  
Intraclass Correlation Coefficients ◽  
Knee Strength ◽  
Hands On ◽  
Angular Velocities

The present study aimed to evaluate the influence of holding the chair handles during the assessment of older women’s knee flexion and extension isokinetic and isometric strength. Of 57 older women (≥60 years) selected from a convenience sample for this research, 23 were randomly chosen to perform the tests twice for reliability analyses. Each participant performed maximal isokinetic knee extension and flexion at 60°/s and 180°/s angular velocities and isometric tests under two conditions: (a) holding the lateral handle of the chair (HOLD) and (b) supporting the hands on the shoulders with the arms crossed (i.e., not holding the handle [NHOLD]). Participants performed significantly better in the HOLD compared with the NHOLD condition. Slightly lower intraclass correlation coefficients (ICC = 0.870–0.956) were noted for the HOLD than for the NHOLD condition (ICC = 0.900–0.981) so that the HOLD performance on Days 1 and 2 was different on some measures. Owing to the higher reliability coefficients in the NHOLD condition, results suggest that, when assessing knee strength in older women, the evaluee should place their hands over their shoulders with arms crossed in front of the chest (NHOLD) to maximize assessment reliability (reproducibility of performance).

Biomechanical Response to Acute Stretching in Dancers and Non-Dancers

2020 ◽  
Vol 24 (1) ◽  
pp. 12-18
Author(s):  
Bárbara Pessali-Marques ◽  
Gustavo H.C. Peixoto ◽  
Christian E.T. Cabido ◽  
André Gustavo P. Andrade ◽  
Sara A. Rodrigues ◽  
...  
Keyword(s):  
Undergraduate Students ◽  
Repeated Measures ◽  
Mechanical Response ◽  
Physical Therapists ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Knee Extension ◽  
Young Males ◽  
Resistance Torque ◽  
Post Test

This study aimed to investigate the bio- mechanical response of the hamstring muscles to acute stretching in dancers (D) compared to non-dancers (ND). Maximal range of motion (ROMMax) and stiffness of the hamstrings were assessed in 46 young males, 23 undergraduate students (ND) and 23 professional dancers (D). Ages of the two groups were D 21.5 ± 0.60 years; ND 27.5 ± 0.98 years). Testing was performed in two sessions, familiarization with procedures in the first session and the tests themselves (pre- and post-test and intervention) in the second, with a 24- to 48-hour interval between. The pre-test consisted of three trials of passive knee extension to the point of increased tension in the hamstrings, defined as ROMMax. The resistance torque recorded at ROMMax was defined as torqueMax. Six 30-second constant torque stretches were performed at 100% of the torqueMaxreached in the pre-test in one lower limb only (intervention), with the contralateral limb used as control. The torque measured at an identical ROM before (pre-test) and after (post-test) the intervention was defined as torqueROM, and represented stiffness in this study. Reliability of the ROMMax, torqueMax, and torqueROMwas assessed via intraclass correlation coefficients (ICC3, k) and standard error of the measurements (SEM). Comparison between dancers and non-dancers, control, and intervention conditions for all dependent variables was performed using ANOVA repeated measures followed by Tukey post hoc comparisons to highlight any interaction. The submaximal stretch intensity applied caused torqueROM to decrease in both D and ND groups (p < 0.01), indicating a decrease in stiffness, but no difference between the groups was found. A significantly greater increase in ROMMax was found for the D group compared to the ND group (p < 0.01), suggesting that other aspects in addition to MTU biomechanical adaptations may have played a role in the ROMMax increase, especially for the D group. Further research is needed to explore what those other adaptations are. Meanwhile, coaches and physical therapists should be aware that dancers may require different stretch training protocols than non-dancers.

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.

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

scholarly journals Capturing patient-reported area of knee pain: a concurrent validity study using digital technology in patients with patellofemoral pain

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4406 ◽  
Author(s):  
Mark Matthews ◽  
Michael S. Rathleff ◽  
Bill Vicenzino ◽  
Shellie A. Boudreau
Keyword(s):  
Knee Pain ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Patellofemoral Pain ◽  
Digital Platforms ◽  
Pain Location ◽  
Significant Difference ◽  
Patient Reported ◽  
Pain Drawings ◽  
Pain Area

Background Patellofemoral pain (PFP) is often reported as a diffuse pain at the front of the knee during knee-loading activities. A patient’s description of pain location and distribution is commonly drawn on paper by clinicians, which is difficult to quantify, report and compare within and between patients. One way of overcoming these potential limitations is to have the patient draw their pain regions using digital platforms, such as personal computer tablets. Objective To assess the validity of using computer tablets to acquire a patient’s knee pain drawings as compared to paper-based records in patients with PFP. Methods Patients (N = 35) completed knee pain drawings on identical images (size and colour) of the knee as displayed on paper and a computer tablet. Pain area expressed as pixel density, was calculated as a percentage of the total drawable area for paper and digital records. Bland–Altman plots, intraclass correlation coefficient (ICC), Pearson’s correlation coefficients and one-sample tests were used in data analysis. Results No significant difference in pain area was found between the paper and digital records of mapping pain area (p = 0.98), with the mean difference = 0.002% (95% CI [−0.159–0.157%]). A very high agreement in pain area between paper and digital pain drawings (ICC = 0.966 (95% CI [0.93–0.98], F = 28.834, df = 31, p < 0.001). A strong linear correlation (R2 = 0.870) was found for pain area and the limits of agreement show less than ±1% difference between paper and digital drawings. Conclusion Pain drawings as acquired using paper and computer tablet are equivalent in terms of total area of reported knee pain. The advantages of digital recording platforms, such as quantification and reporting of pain area, could be realized in both research and clinical settings.

Central activation deficits contribute to post stroke lingual weakness in a rat model

2021 ◽  
Author(s):  
Miranda J. Cullins ◽  
John A. Russell ◽  
Zoe E. Booth ◽  
Nadine P. Connor
Keyword(s):  
Muscle Fiber ◽  
Muscle Activation ◽  
Fiber Type ◽  
Muscle Fiber Type ◽  
Force Frequency ◽  
Muscle Twitch ◽  
Central Activation ◽  
Central Activation Ratio ◽  
Generating Capacity ◽  
Activation Ratio

Lingual weakness frequently occurs after stroke and is associated with deficits in speaking and swallowing. Chronic weakness after stroke has been attributed to both impaired central activation of target muscles and reduced force generating capacity within muscles. How these factors contribute to lingual weakness is not known. We hypothesized that lingual weakness due to middle cerebral artery occlusion (MCAO) would manifest as reduced muscle force capacity and reduced muscle activation. Rats were randomized into MCAO or sham surgery groups. Maximum volitional tongue forces were quantified 8 weeks after surgery. Hypoglossal nerve stimulation was used to assess maximum stimulated force, muscle twitch properties, and force-frequency response. The central activation ratio was determined by maximum volitional/maximum stimulated force. Genioglossus muscle fiber type properties and neuromuscular junction innervation were assessed. Maximum volitional force and the central activation ratio were significantly reduced with MCAO. Maximum stimulated force was not significantly different. No significant differences were found for muscle twitch properties, unilateral contractile properties, muscle fiber type percentages, or fiber size. However, the twitch/tetanus ratio was significantly increased in the MCAO group relative to sham. A small but significant increase in denervated NMJs and fiber-type grouping occurred in the contralesional genioglossus. Results suggest the primary cause of chronic lingual weakness after stroke is impaired muscle activation rather than a deficit of force generating capacity in lingual muscles. Increased fiber type grouping and denervated NMJs in the contralesional genioglossus suggest partial reinnervation of muscle fibers may have preserved force generating capacity, but not optimal activation patterns.

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