Reliability of maximal isometric knee strength testing with modified hand-held dynamometry in patients awaiting total knee arthroplasty: useful in research and individual patient settings? A reliability study

<p>Abstract</p> <p><b>Background</b></p> <p>Patients undergoing total knee arthroplasty (TKA) often experience strength deficits both pre- and post-operatively. As these deficits may have a direct impact on functional recovery, strength assessment should be performed in this patient population. For these assessments, reliable measurements should be used. This study aimed to determine the inter- and intrarater reliability of hand-held dynamometry (HHD) in measuring isometric knee strength in patients awaiting TKA.</p> <p><b>Methods</b></p> <p>To determine interrater reliability, 32 patients (81.3% female) were assessed by two examiners. Patients were assessed consecutively by both examiners on the same individual test dates. To determine intrarater reliability, a subgroup (n = 13) was again assessed by the examiners within four weeks of the initial testing procedure. Maximal isometric knee flexor and extensor strength were tested using a modified Citec hand-held dynamometer. Both the affected and unaffected knee were tested. Reliability was assessed using the Intraclass Correlation Coefficient (ICC). In addition, the Standard Error of Measurement (SEM) and the Smallest Detectable Difference (SDD) were used to determine reliability.</p> <p><b>Results</b></p> <p>In both the affected and unaffected knee, the inter- and intrarater reliability were good for knee flexors (ICC range 0.76-0.94) and excellent for knee extensors (ICC range 0.92-0.97). However, measurement error was high, displaying SDD ranges between 21.7% and 36.2% for interrater reliability and between 19.0% and 57.5% for intrarater reliability. Overall, measurement error was higher for the knee flexors than for the knee extensors.</p> <p><b>Conclusions</b></p> <p>Modified HHD appears to be a reliable strength measure, producing good to excellent ICC values for both inter- and intrarater reliability in a group of TKA patients. High SEM and SDD values, however, indicate high measurement error for individual measures. This study demonstrates that a modified HHD is appropriate to evaluate knee strength changes in TKA patient groups. However, it also demonstrates that modified HHD is not suitable to measure individual strength changes. The use of modified HHD is, therefore, not advised for use in a clinical setting.</p

Cross-cultural adaptation of the VISA-A questionnaire, an index of clinical severity for patients with Achilles tendinopathy, with reliability, validity and structure evaluations

BACKGROUND: Achilles tendinopathy is considered to be one of the most common overuse injuries in elite and recreational athletes and the recommended treatment varies. One factor that has been stressed in the literature is the lack of standardized outcome measures that can be used in all countries. One such standardized outcome measure is the Victorian Institute of Sports Assessment – Achilles (VISA-A) questionnaire, which is designed to evaluate the clinical severity for patients with Achilles tendinopathy. The purpose of this study was to cross-culturally adapt the VISA-A questionnaire to Swedish, and to perform reliability, validity and structure evaluations. METHODS: Cross-cultural adaptation was performed in several steps including translations, synthesis of translations, back translations, expert committee review and pre-testing. The final Swedish version, the VISA-A Swedish version (VISA-A-S) was tested for reliability on healthy individuals (n = 15), and patients (n = 22). Tests for internal consistency, validity and structure were performed on 51 patients. RESULTS: The VISA-A-S had good reliability for patients (r = 0.89, ICC = 0.89) and healthy individuals (r = 0.89–0.99, ICC = 0.88–0.99). The internal consistency was 0.77 (Cronbach's alpha). The mean [95% confidence interval] VISA-A-S score in the 51 patients (50 [44–56]) was significantly lower than in the healthy individuals (96 [94–99]). The VISA-A-S score correlated significantly (Spearman's r = -0.68) with another tendon grading system. Criterion validity was considered good when comparing the scores of the Swedish version with the English version in both healthy individuals and patients. The factor analysis gave the factors pain/symptoms and physical activity CONCLUSION: The VISA-A-S questionnaire is a reliable and valid instrument and comparable to the original version. It measures two factors: pain/symptoms and physical activity, and can be used in both research and the clinical setting

Intra-rater reliability, measurement precision, and inter-test correlations of 1RM single-leg leg-press, knee-flexion, and knee-extension in uninjured adult agility-sport athletes: Considerations for right and left unilateral measurements in knee injury control

Objectives Knowledge of single-leg knee strength test reliability for the right and left limb is critical for between-limb clinical decision-making. Knowledge of between-test correlations is essential for understanding whether tests measure similar or different aspects of muscle strength. This study investigated the intra-rater, test-retest reliability and measurement precision of one repetition maximum (1RM) single-leg leg-press (LP), knee-flexion (KF), and knee-extension (KE) for both limbs, and inter-test correlations. Design Repeated measures; Setting University. Participants Six males, seven females (age 25.6±5.5yr; height 171.4±8.4cm; mass 71.8±13.4kg). Main outcome measures Normalised 1RM (percent body-mass (%BM)), intraclass correlation coefficient (ICC) (Avery, 1995; Rivara, 2003), standard error of measurement (SEM; %BM), Pearson's correlation (r), coefficient of determination (r2). Results Mean 1RM test-retest values were (right, left): LP, 214.2–218.5%BM, 213.5–215.4%BM; KF, 35.9–38.9%BM, 37.7–38.2%BM; KE, 43.3–44.6%BM, 36.2–39.3%BM. The ICCs/SEMs were (right, left): LP, 0.98/7.3%BM, 0.94/14.2%BM; KF, 0.75/4.9%BM, 0.95/1.9%BM; KE, 0.87/3.4%BM, 0.78/4.4%BM. Correlations were significant (P < 0.01), r/r2 values were: LP-KF, 0.60/0.36; LP-KE, 0.59/0.35; KF-KE, 0.50/0.25. Conclusions Tests demonstrated good reliability and measurement precision, although ICCs and SEMs were different between limbs. Tests were correlated, but only one-third of the variance was shared between tests. Practitioners should be cognisant of between-limb differences in reliability and include all tests for knee clinical decision-making

In patients eligible for meniscal surgery who first receive physical therapy, multivariable prognostic models cannot predict who will eventually undergo surgery

Purpose Although physical therapy is the recommended treatment in patients over 45 years old with a degenerative meniscal tear, 24% still opt for meniscal surgery. The aim was to identify those patients with a degenerative meniscal tear who will undergo surgery following physical therapy. Methods The data for this study were generated in the physical therapy arm of the ESCAPE trial, a randomized clinical trial investigating the effectiveness of surgery versus physical therapy in patients of 45-70 years old, with a degenerative meniscal tear. At 6 and 24 months patients were divided into two groups: those who did not undergo surgery, and those who did undergo surgery. Two multivariable prognostic models were developed using candidate predictors that were selected from the list of the patients' baseline variables. A multivariable logistic regression analysis was performed with backward Wald selection and a cut-off of p < 0.157. For both models the performance was assessed and corrected for the models' optimism through an internal validation using bootstrapping technique with 500 repetitions. Results At 6 months, 32/153 patients (20.9%) underwent meniscal surgery following physical therapy. Based on the multivariable regression analysis, patients were more likely to opt for meniscal surgery within 6 months when they had worse knee function, lower education level and a better general physical health status at baseline. At 24 months, 43/153 patients (28.1%) underwent meniscal surgery following physical therapy. Patients were more likely to opt for meniscal surgery within 24 months when they had worse knee function and a lower level of education at baseline at baseline. Both models had a low explained variance (16 and 11%, respectively) and an insufficient predictive accuracy. Conclusion Not all patients with degenerative meniscal tears experience beneficial results following physical therapy. The non-responders to physical therapy could not accurately be predicted by our prognostic models.Orthopaedics, Trauma Surgery and Rehabilitatio

Evidence-based clinical practice update: practice guidelines for anterior cruciate ligament rehabilitation based on a systematic review and multidisciplinary consensus

AIM: The Royal Dutch Society for Physical Therapy (KNGF) instructed a multidisciplinary group of Dutch anterior cruciate ligament (ACL) experts to develop an evidence statement for rehabilitation after ACL reconstruction. DESIGN: Clinical practice guideline underpinned by systematic review and expert consensus. DATA SOURCES: A multidisciplinary working group and steering group systematically reviewed the literature and wrote the guideline. MEDLINE and the Cochrane Library were searched for meta-analyses, systematic reviews, randomised controlled trials and prospective cohort studies published between January 1990 and June 2015. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Included literature must have addressed 1 of 9 predetermined clinical topics: (1) preoperative predictors for postoperative outcome, (2) effectiveness of physical therapy, (3) open and closed kinetic chain quadriceps exercises, (4) strength and neuromuscular training, (5) electrostimulation and electromyographic feedback, (6) cryotherapy, (7) measurements of functional performance, (8) return to play and (9) risk for reinjury. SUMMARY: Ninety studies were included as the basis for the evidence statement. Rehabilitation after ACL injury should include a prehabilitation phase and 3 criterion-based postoperative phases: (1) impairment-based, (2) sport-specific training and (3) return to play. A battery of strength and hop tests, quality of movement and psychological tests should be used to guide progression from one rehabilitation stage to the next. Postoperative rehabilitation should continue for 9-12 months. To assess readiness to return to play and the risk for reinjury, a test battery, including strength tests, hop tests and measurement of movement quality, should be used

Force balancing in mammographic compression

In mammography, the height of the image receptor is adjusted to the patient before compressing the breast. An inadequate height setting can result in an imbalance between the forces applied by the image receptor and the paddle, causing the clamped breast to be pushed up or down relative to the body during compression. This leads to unnecessary stretching of the skin and other tissues around the breast, which can make the imaging procedure more painful for the patient. The goal of this study was to implement a method to measure and minimize the force imbalance, and to assess its feasibility as an objective and reproducible method of setting the image receptor height. A trial was conducted consisting of 13 craniocaudal mammographic compressions on a silicone breast phantom, each with the image receptor positioned at a different height. The image receptor height was varied over a range of 12 cm. In each compression, the force exerted by the compression paddle was increased up to 140 N in steps of 10 N. In addition to the paddle force, the authors measured the force exerted by the image receptor and the reaction force exerted on the patient body by the ground. The trial was repeated 8 times, with the phantom remounted at a slightly different orientation and position between the trials. For a given paddle force, the obtained results showed that there is always exactly one image receptor height that leads to a balance of the forces on the breast. For the breast phantom, deviating from this specific height increased the force imbalance by 9.4 ± 1.9 N/cm (6.7%) for 140 N paddle force, and by 7.1 ± 1.6 N/cm (17.8%) for 40 N paddle force. The results also show that in situations where the force exerted by the image receptor is not measured, the craniocaudal force imbalance can still be determined by positioning the patient on a weighing scale and observing the changes in displayed weight during the procedure. In mammographic breast compression, even small changes in the image receptor height can lead to a severe imbalance of the applied forces. This may make the procedure more painful than necessary and, in case the image receptor is set too low, may lead to image quality issues and increased radiation dose due to undercompression. In practice, these effects can be reduced by monitoring the force imbalance and actively adjusting the position of the image receptor throughout the compressio