Quadriceps Rate of Torque Development and Disability in Persons With Tibiofemoral Osteoarthritis

The association between knee muscle performance and clinical outcomes of knee function 1-4 years after a sport-related knee joint injury

OBJECTIVE

Estimate the association between index leg knee muscle strength and rate of torque development (RTD), and self-reported and performance-based (i.e., hop) knee function in persons 1-4 years after a sport-related knee joint injury.

METHODS

Data were collected at baseline of a clinical trial. Assessments included the Knee injury and Osteoarthritis Outcome Score Sport & Recreation subscale (KOOSsport), 6-m timed hop (TH), and peak concentric isokinetic knee extensor and flexor torque and isometric RTD. Associations between peak torque and RTD with KOOSsport and TH were assessed using multivariable regression with nonlinear transformations.

RESULTS

53 participants (64.2% female) were included. Knee extensor peak torque was nonlinearly related to TH time, with a strong inverse relationship at lower torque values that changed as torque increased. Results were inconsistent for flexor peak torque, extensor RTD and flexor RTD, with inconsistencies in relationship shape and estimates of association between primary and sensitivity analyses. There was no association between strength/RTD and KOOSsport.

CONCLUSION

There was a nonlinear relationship between knee extensor strength and hop function, with lower strength being associated with a stronger relationship. As strength values increased, the relationship attenuated. Knee extensor and flexor strength, or RTD, were not associated with self-reported function.

Changes in biomechanics, strength, physical function, and daily steps after extended-release corticosteroid injections in knee osteoarthritis: a responder analysis

INTRODUCTION/OBJECTIVE

To determine changes in gait biomechanics, quadricep strength, physical function, and daily steps after an extended-release corticosteroid knee injection at 4 and 8 weeks post-injection in individuals with knee osteoarthritis as well as between responders and non-responders based on changes in self-reported knee function.

METHOD

The single-arm, clinical trial included three study visits (baseline, 4 weeks, and 8 weeks post-injection), where participants received an extended-release corticosteroid injection following the baseline visit. Time-normalized vertical ground reaction force (vGRF), knee flexion angle (KFA), knee abduction moment (KAM), and knee extension moment (KEM) waveforms throughout stance were collected during gait biomechanical assessments. Participants also completed quadricep strength, physical function (chair-stand, stair-climb, 20-m fast-paced walk) testing, and free-living daily step assessment for 7 days following each visit.

RESULTS

All participants demonstrated increased KFA excursion (i.e., greater knee extension angle at heel strike and KFA at toe-off), increased KEM during early stance, improved physical function (all p < 0.001), and increased quadricep strength at 4 and 8 weeks. KAM increased throughout most of stance at 4 and 8 weeks post-injection (p < 0.001) but appears to be driven by gait changes in non-responders. Non-responders demonstrated lesser vGRF during late stance and lesser KEM and KFA throughout stance compared to responders at baseline.

CONCLUSIONS

Extended-release corticosteroid injections demonstrated short-term improvements in gait biomechanics, quadricep strength, and physical function for up to 4 weeks. However, non-responders demonstrated gait biomechanics associated with osteoarthritis progression prior to the corticosteroid injection, suggesting that non-responders demonstrate more deleterious gait biomechanics prior to corticosteroid injection. Key Points • Individuals with knee osteoarthritis who were treated with extended-release corticosteroid injections demonstrated improvements in gait biomechanics and physical function for 8 weeks. • Individuals with knee osteoarthritis, who walked with aberrant walking biomechanics before treatment, failed to respond to extended-release corticosteroid treatment. • Future research should determine the mechanisms contributing to the short-term changes in gait biomechanics and physical function such as reduced inflammation.

Effects of mat Pilates on older adult women with knee osteoarthritis: A randomized controlled trial

INTRODUCTION

Osteoarthritis is the most common joint disorder in the world and its incidence is rising, and one of the most frequent causes of pain, loss of function and disability in adults.

AIM

The aim of this study was to evaluate the effects of Mat Pilates on health status, pain, stiffness, and functionality of older adult women with knee osteoarthritis (KOA).

METHODS

A randomized-controlled trial to preliminarily test an intervention protocol of Mat Pilates in older women with KOA on health status, pain, stiffness, and functionality. This study included 41 volunteers with age over 40 years, which mean was 52.1 ± 8.9 years, and were allocated into Mat Pilates and control groups. The protocol was developed to be performed in 60 min, twice a week; the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Medical Outcomes Study 36 (SF-36) were used to assess pain, to evaluate functionality and stiffness.

RESULTS

The Mat Pilates group significantly improved the functional capacity assessed by SF-36 (33.12 ± 22.03 to 69.37 ± 22.43, p < 0.05), and by WOMAC (29.75 ± 6.92 to 9.75 ± 9.35, p < 0.05). The pain domain also improved in Mat Pilates group assessed by SF-36 (39.50 ± 12.89 to 71.75 ± 18.66, p < 0.05) and by WOMAC (8.00 ± 2.56 to 2.75 ± 3.01, p < 0.05). The total score of WOMAC (41.75 ± 10.39 to 14.25 ± 13.88, p < 0.05), and the general health status assessed by SF-36 (59.44 ± 18.07 to 82.75 ± 12.03, p < 0.05) only improved for Mat Pilates group. No differences were observed in outcomes for the control group in both questionnaires.

CONCLUSION

Our results show that Mat Pilates protocol can improve the health status, pain, and functionality of older women with KOA.

Adapted protocol of rate of force development and relaxation scaling factor for neuromuscular assessment in patients with knee osteoarthritis

BACKGROUND

The linear relationship between muscle torque and rate of torque rise/relaxation during rapid muscle contractions has been recently introduced as a novel measure of muscle quickness, termed rate of torque development/relaxation scaling factor (RTD-SF/RTR-SF). Because the standard assessment protocol includes potentially painful muscle contractions, the first purpose of this study was to validate an adapted RTD-SF/RTR-SF protocol for knee extensor muscles that utilizes lower submaximal intensities and can be used in knee osteoarthritis patients.

METHODS

A cross-sectional study was performed on a group of healthy controls (n = 24) who underwent the standard RTD-SF/RTR-SF protocol (20-80% of maximum) and the knee osteoarthritis group (n = 24) who underwent the adapted protocol (20-60% of maximum). We calculated the RTD-SF, RTR-SF and the linearity (r²) for both relationships, based on both protocols in controls.

RESULTS

The validity of the adapted protocol was acceptable (intraclass correlation coefficient = 0.77-0.93), with low within-participant variation (coefficient of variability <10%) for both outcome measures. Compared with the control group, the knee osteoarthritis group had similar RTD-SF, but lower linearity of RTD-SF (0.90 vs. 0.82). The RTR-SF (8.0/s vs. 6.7/s) and its linearity (0.87 vs. 0.73) were significantly reduced. Comparing the affected and the unaffected leg in the knee osteoarthritis group, the unaffected leg had greater maximal torque (96.2 vs. 84.1 Nm) and higher linearity for RTD-SF (0.86 vs. 0.80) and RTR-SF (0.82 vs. 0.73).

CONCLUSIONS

We confirmed the validity of the adapted RTD/RTR-SF protocol and its sensitivity to impairments associated with knee osteoarthritis.

A Narrative Review on Measurement Properties of Fixed-distance Walk Tests Up to 40 Meters for Adults With Knee Osteoarthritis

Knee osteoarthritis (OA) is a serious disease and has no cure to date. Knee OA is a leading cause of functional limitation (e.g., difficulty walking). Walking speed is 1 method of quantifying difficulty with walking and should be assessed in clinical practice for adults with knee OA because it has prognostic value and is modifiable. Specifically, slow walking speed is associated with increased risk of adverse health outcomes, including all-cause mortality in adults with knee OA and can be modified by engaging in physical activity or exercise. However, at present, there is little consensus on the distance and instructions used to conduct the walk test. Distance is often selected based on space availability, and instruction varies, from asking the participants to walk at a comfortable pace versus as fast as possible. Therefore, the purpose of this narrative review is to summarize the measurement properties, strengths, and limitations of a fixed-distance walk test ≤ 40 meters in adults with knee OA. Good measurement properties in terms of reliability and validity were observed across the different testing protocols for fixed-distance walk test (i.e., any distance ≤ 40 m and fast- or self-paced). Therefore, clinicians and researchers can select a testing protocol that can safely and consistently be performed over time, as well as provide a practice trial to acclimatize the patients to the fixed-distance walk test.

Using TENS to Enhance Therapeutic Exercise in Individuals with Knee Osteoarthritis

Transcutaneous electrical nerve stimulation (TENS) facilitates quadriceps voluntary activation in experimental settings. Augmenting therapeutic exercise (TE) with TENS may enhance the benefits of TE in individuals with knee osteoarthritis (KOA) and quadriceps voluntary activation failure (QVAF).

PURPOSE

This study aimed to determine the effect of TENS + TE on patient-reported function, quadriceps strength, and voluntary activation, as well as physical performance compared with sham TENS + TE (Sham) and TE alone in individuals with symptomatic KOA and QVAF.

METHODS

Ninety individuals participated in a double-blinded randomized controlled trial. Everyone received 10 standardized TE sessions of physical therapy. TENS + TE and Sham groups applied the respective devices during all TE sessions and throughout activities of daily living over 4 wk. The Western Ontario and McMaster University Osteoarthritis Index (WOMAC), quadriceps strength, and voluntary activation, as well as a 20-m walk test, chair-stand test, and stair-climb test were performed at baseline, after the 4-wk intervention (post 1) and at 8 wk after the start of the intervention (post 2). Mixed-effects models were used to determine between-group differences between baseline and post 1, as well as baseline and post 2.

RESULTS

Improvements in WOMAC subscales, quadriceps strength, and voluntary activation, 20-m walk times, chair-stand repetitions, and stair-climb time were found at post 1 and post 2 compared with baseline for all groups (P < 0.05). WOMAC Pain and Stiffness improved in the TENS + TE group compared with TE alone at post 1 (P < 0.05); yet, no other between-group differences were found.

CONCLUSIONS

TE effectively improved patient-reported function, quadriceps strength, and voluntary activation, as well as physical performance in individuals with symptomatic KOA and QVAF, but augmenting TE with TENS did not improve the benefits of TE.