Effect of verbal encouragement on quadriceps and knee joint function during three sets of knee extension exercise

2020 ◽  
pp. 1-7
Author(s):  
Hyunwook Lee ◽  
Jaeyoon Shin ◽  
Daeho Kim ◽  
Jihong Park
Keyword(s):  
Knee Joint ◽  
Knee Flexion ◽  
Knee Extension ◽  
Quadriceps Strength ◽  
Contributing Factors ◽  
Force Output ◽  
Joint Function ◽  
Central Activation ◽  
Verbal Encouragement ◽  
Knee Extension Exercise

BACKGROUND: Although the common practice of verbal encouragement is scientifically supported, its effect on the maintenance of force output in fatiguing exertions is unknown. OBJECTIVE: To examine the effects of verbal encouragement on exercise-induced quadriceps and knee joint function during three sets of knee extension exercise. METHODS: Sixty-five healthy males (23.3 years, 175.8 cm, 75.3 kg) underwent testing using the administration of verbal encouragement (n= 32) or not (n= 33) during assessment of quadriceps and knee joint function. Assessments were performed at baseline and times 1, 2, and 3. The knee concentric isokinetic extension at 60∘/s, was performed between the time points. For quadriceps function, maximal isometric strength and activation (central activation ratio) were recorded. Absolute error values on knee flexion replications at 15∘ or 45∘ were recorded for knee joint function. RESULTS: There was no verbal encouragement effect over three sets of exercise in quadriceps strength (condition × time: F3,189= 1.71, p= 0.17) and knee flexion replication (condition × time for 15∘: F3,189= 0.11, p= 0.96; 45∘: F3,189= 0.63, p= 0.6). However, subjects who had received verbal encouragement maintained quadriceps activation (condition × time: F3,189= 5.49, p= 0.001). Specifically, quadriceps activation in the verbal condition was 3.0% higher at time 2 (p= 0.01) and 4.7% higher at time 3 (p= 0.0003) versus in the non-verbal condition. CONCLUSIONS: Verbal encouragement appears to be effective in maintaining central activation, but is insufficient for promoting strength. This supports the idea that peripheral contributing factors play a larger role in force production when performing multiple sets of exercises.

scholarly journals Criterion-Related Validity of Knee Joint-Position-Sense Measurement Using Image Capture and Isokinetic Dynamometry

2015 ◽  
Vol 24 (1) ◽  
Author(s):  
Nicola Relph ◽  
Lee Herrington
Keyword(s):  
Knee Joint ◽  
Knee Flexion ◽  
Cost Effective ◽  
Absolute Error ◽  
Knee Extension ◽  
Position Sense ◽  
Joint Position Sense ◽  
Joint Position ◽  
Image Capture ◽  
Significant Difference

Context: Clinicians require portable, valid, and cost-effective methods to monitor knee joint-position-sense (JPS) ability. Objective: To examine the criterion-related validity of image-capture JPS measures against an isokinetic-dynamometer (IKD) procedure. Design: Random crossover design providing a comparison of knee JPS measures from image capture and IKD procedures. Participants: 10 healthy participants, 5 female, age 28.0 ± 13.29 y, mass 60.3 ± 9.02 kg, height 1.65 ± 0.07 m, and 5 male, 29.6 ± 10.74 y, mass 73.6 ± 5.86 kg, height 1.75 ± 0.07 m. Main Outcome Measures: The dependent variables were absolute error scores (AES) provided by 2 knee directions (flexion and extension). The independent variables were the method (image capture and IKD). Results: There was no significant difference between clinical and IKD AED into knee-extension data (P = .263, r = 0.55). There was a significant difference between clinical and IKD AES into knee-flexion data (P = .016, r =.70). Conclusions: Analysis of photographic images to assess JPS measurements using knee flexion is valid against IKD techniques. However, photo-analysis measurements provided a lower error score using knee-extension data and thus may provide an optimal environment to produce maximal knee JPS acuity. Therefore, clinicians do not need expensive equipment to collect representative JPS ability.

scholarly journals Gait Biomechanics in Individuals Meeting Sufficient Quadriceps Strength Cutoffs Following Anterior Cruciate Ligament Reconstruction

2021 ◽  
Author(s):  
Brian Pietrosimone ◽  
Hope C. Davis-Wilson ◽  
Matthew K. Seeley ◽  
Christopher Johnston ◽  
Jeffrey T. Spang ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Knee Flexion ◽  
Ligament Reconstruction ◽  
Stance Phase ◽  
Cruciate Ligament ◽  
Knee Extension ◽  
Quadriceps Strength ◽  
Cruciate Ligament Reconstruction ◽  
Gait Biomechanics ◽  
Anterior Cruciate

Abstract Context: Quadriceps weakness is associated with disability and aberrant gait biomechanics following anterior cruciate ligament reconstruction (ACLR). Strength sufficiency cutoff scores, that normalize quadriceps strength to the mass of an individual, are capable of predicting individuals who will report better function following ACLR. Yet, it remains unknown if gait biomechanics differ between individuals who meet a strength sufficiency cutoff (strong) compared to those who do not (weak). Objective: Determine if vertical ground reaction force (vGRF), knee flexion angle (KFA) and internal knee extension moment (KEM) differ between strong and weak individuals with an ACLR throughout stance phase of walking. Design: Comparison-control. Setting: Laboratory Participants: Individuals who received unilateral ACLR ≥12 months prior to testing were dichotomized into strong (n=31) and weak groups (n=116). Main Outcome Measures: Maximal isometric quadriceps strength was collected at 90° of knee flexion using an isokinetic dynamometer and normalized to body mass. Individuals demonstrating ≥3.0Nm/kg were considered strong. Three-dimensional gait biomechanics were collected at a self-selected walking speed. Biomechanical data were time-normalized to 100% of stance phase. vGRF were normalized to body weight (BW), and KEM was normalized to BW*height. Pairwise comparison functions were calculated for each outcome to identify between-group differences for each percentile of stance. Results: vGRF was significantly greater in weak participants for the first 22% of stance (average difference of 6.2% BW) and lesser in weak participants between 36–43% of stance (1.4% BW). KFA was significantly greater (i.e., more flexion) in strong participants between 6–62% of stance (2.3°) and lesser (i.e., less flexion) between 68-79% of stance (1.0°). KEM was significantly greater in strong participants between 7–62% of stance (0.007 BW*height). Conclusions: ACLR individuals able to generate knee extension torque ≥3.0Nm/kg exhibit different biomechanical gait profiles compared to weak individuals, which may allow for better energy attenuation following ACLR.

scholarly journals Effects of a Single Session of Floss Band Intervention on Flexibility of Thigh, Knee Joint Proprioception, Muscle Force Output, and Dynamic Balance in Young Adults

2021 ◽  
Vol 11 (24) ◽  
pp. 12052
Author(s):  
Nai-Jen Chang ◽  
Wei-Chun Hung ◽  
Chia-Lun Lee ◽  
Wen-Dien Chang ◽  
Bo-Han Wu
Keyword(s):  
Young Adults ◽  
Knee Joint ◽  
Muscle Force ◽  
Dynamic Balance ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Force Output ◽  
Significant Difference ◽  
Hamstring Flexibility ◽  
Knee Muscle

The floss band (FB) has been correlated with increases in the joint range of motion (ROM). However, the literature on FB effectiveness in knee joint ROM and athletic performance remains sparse. This study investigated the effects of FB on the flexibility of the quadriceps and hamstrings, knee joint proprioception, muscle force output, and dynamic balance in men. Thirty recreationally active men without musculoskeletal disorders were randomized to receive FB (Lime Green; Sanctband flossband) and elastic bandage (EB) intervention on the dominant knee joint. Participants received two interventions on two occasions with 2 days of rest between interventions. The primary outcome was the flexibility of the quadriceps and hamstrings; the secondary outcomes were knee proprioception (joint reposition angle error), knee muscle force output, and dynamic balance. Preintervention and postintervention (immediately following band removal and 20 min later) measurements were obtained. After FB intervention, hamstring flexibility (immediately: p < 0.001; 20 min later: p < 0.001) and quadriceps flexibility (immediately: p < 0.001; 20 min later: p < 0.001), quadriceps muscle force output (immediately: p = 0.007; 20 min later: p < 0.001), and dynamic balance (both immediately and 20 min later, p < 0.001) were significantly improved. Compared with EB intervention, FB intervention significantly improved knee extension ROM (immediately and 20 min later, both p < 0.001), knee flexion ROM (immediately, p = 0.01; 20 min later, p = 0.03), hamstrings muscle force output (20 min later, p = 0.022) and dynamic balance (immediately, p = 0.016; 20 min later, p = 0.004). Regarding proprioception, no significant difference among time points and conditions was observed. In conclusion, FB intervention can significantly improve the flexibility of the quadriceps and hamstrings, quadriceps muscle force output, and dynamic balance without impeding knee proprioception. Physiotherapists or athletic professionals may consider FB intervention as a potential tool as a warmup to enhance the flexibility of the quadriceps and hamstrings, quadriceps muscle force output, and dynamic balance in young adults.

A Biologically Inspired Knee Actuator for a KAFO

2016 ◽  
Vol 10 (4) ◽  
Author(s):  
Feng Tian ◽  
Mohamed Samir Hefzy ◽  
Mohammad Elahinia
Keyword(s):  
Knee Joint ◽  
Knee Flexion ◽  
Gait Cycle ◽  
Knee Extension ◽  
Lateral Side ◽  
Walking Gait ◽  
Normal Knee ◽  
Knee Stiffness ◽  
Control Knee ◽  
Stiffness Profile

Knee–ankle–foot orthoses (KAFOs) are prescribed to improve abnormal ambulation caused by quadriceps weakness. There are three major types of KAFOs: passive KAFOs, semidynamic KAFOs, and dynamic KAFOs. Dynamic KAFOs are the only type that enables to control knee motions throughout the entire walking gait cycle. However, those available in the market are heavy, bulky, and have limited functionality. The UT dynamic KAFO is developed to allow knee flexion and assist knee extension over the gait cycle by using a superelastic nitinol actuator, which has the potential to reduce volume and weight and reproduce normal knee behavior. In order to match the normal knee stiffness profile, the dynamic actuator consists of two actuating parts that work in the stance and swing phases, respectively. Each actuating part combines a superelastic torsional rod and a torsional spring in parallel. Geometries of the two superelastic rods were determined by matlab-based numerical simulations. The simulation response of the dynamic actuator was compared with the normal knee stiffness, verifying that the proposed design is able to mimic the normal knee performance. The surrounding parts of the dynamic knee joint have then been designed and modeled to house the two actuating parts. The dynamic knee joint was fabricated and mounted on a conventional passive KAFO, replacing its original knee joint on the lateral side. Motion analysis tests were conducted on a healthy subject to evaluate the feasibility of the UT dynamic KAFO. The results indicate that the UT dynamic KAFO allows knee flexion during the swing phase of gait and provides knee motion close to normal.

scholarly journals Influence of Patella thickness on Patellofemoral pressure in total knee Arthroplasty

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Hidenori Tanikawa ◽  
Mitsunori Tada ◽  
Ryo Ogawa ◽  
Kengo Harato ◽  
Yasuo Niki ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Joint ◽  
Knee Arthroplasty ◽  
Knee Flexion ◽  
Patellofemoral Joint ◽  
Joint Function ◽  
Custom Made ◽  
Total Knee ◽  
Patellar Thickness ◽  
Patellofemoral Pressure

Abstract Background Patellofemoral complications are one of the major issues after total knee arthroplasty (TKA). Excessive patellofemoral joint pressure is associated with complications after TKA surgery, and the amount of patellar osteotomy has a direct effect on patellofemoral joint pressure. The purpose of this study was to evaluate the influence of patella thickness on patellofemoral pressure in TKA. Methods Five freshly frozen cadavers were operated with a custom-made Stryker posterior stabilizing type knee joint prosthesis. Patellofemoral joint pressure was measured using a pressure sensor, with the knee joint flexed from 90 to 110 degrees, and with patellar thickness of − 2 mm to + 4 mm. Results Increasing or decreasing patellar thickness significantly increased or decreased patellofemoral pressure. Regarding knee flexion angle, patellofemoral pressure increased with increasing patellar thickness at all flexion angles, but the pressure increase was greatest at 90 degrees of knee flexion and smallest at 110 degrees. Conclusions The amount of patellar osteotomy influences the patellofemoral pressure. Surgeons should avoid increasing patella thickness, since the resulting increased patellofemoral pressure may reduce knee joint function.

scholarly journals The Training Effect of Early Intervention with a Hybrid Assistive Limb after Total Knee Arthroplasty

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Takashi Fukaya ◽  
Hirotaka Mutsuzaki ◽  
Kenichi Yoshikawa ◽  
Ayumu Sano ◽  
Masafumi Mizukami ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Joint ◽  
Knee Arthroplasty ◽  
Knee Extensor ◽  
Knee Extension ◽  
Walking Ability ◽  
Joint Function ◽  
Timed Up And Go ◽  
Total Knee ◽  
Hybrid Assistive Limb

After total knee arthroplasty (TKA), it is important for patients to show early improvements in knee joint function and walking to regain independence in performing the activities of daily life. We conducted for 4 weeks an intervention one week after TKA using a hybrid assistive limb (HAL: unilateral leg type) as an exoskeleton robotic device to facilitate knee joint function and walking. The intervention improved the range of knee extension movement safely and without pain compared to preoperation. In addition, we found that training with the HAL improved walking ability, speed, and rate, as well as the time taken to perform the timed up and go (TUG) test compared to preoperation. The strength of the quadriceps muscle did not improve with training; however, the patient was able to induce a knee extensor moment during the initial stance phase, as measured by kinetics and kinematics, and these actions could be performed without pain. HAL training soon after TKA improved knee joint function in a 76-year-old patient who presented with OA of the knee. The improvements in knee extension lag and knee extensor moment allowed the patient to walk without pain and regain ADL in comparison with preoperation.

What Determines the Magnitude of the Q Angle? A Preliminary Study of Selected Skeletal and Muscular Measures

2000 ◽  
Vol 9 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Timo Byl ◽  
Jennifer A. Cole ◽  
Lori A. Livingston
Keyword(s):  
Outcome Measures ◽  
Peak Torque ◽  
Knee Extension ◽  
Quadriceps Strength ◽  
Femur Length ◽  
Q Angle ◽  
Preliminary Study ◽  
The Right ◽  
Knee Extension Exercise

Context:Q-angle size has been found to correlate poorly with skeletal measures of pelvic breadth and femur length. Because the patella is exposed to the forces of quadriceps contraction, muscular forces might also affect Q-angle magnitude.Objective:To compare bilateral measurements of the Q angle with selected skeletal and muscular strength measures.Design:In vivo study of anthropometric and quadriceps peak torque measures.Setting:Research laboratory.Participants:Thirty-four healthy men and women, mean age 20.9 ± 2.7 years.Main Outcome Measures:Q angles, pelvic breadths, femur lengths, and peak torque during dynamic knee-extension exercise, normalized to body weight.Results:Significant differences in Q-angle magnitude, femur length, and peak torqueBW were observed between sexes, but not between limbs. Pelvic breadth did not differ significantly between sexes. Correlational analysis revealed a weak, yet significant, linear relationship between Q angle and peak torqueBW in the right lower limb.Conclusions:These findings lend some support to the notion that Q-angle magnitude is inversely related to quadriceps strength.

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