Reliability, responsiveness, and validity of handheld dynamometry for assessing quadriceps strength in total knee arthroplasty.

PURPOSE: To determine the reliability, responsiveness, validity, and agreement of handheld dynamometry, relative to electromechanical dynamometry, for assessing quadriceps strength surrounding total knee arthroplasty. METHODS: Fifty-six patients (48% female) undergoing total knee arthroplasty were assessed prior to surgery and at 2 and 6 weeks following surgery. Maximum isometric quadriceps force was assessed at each time point by handheld dynamometry and electromechanical dynamometry. Within-session test-retest reliability was determined by intraclass correlation coefficient (ICC). Standard error of measurement and relative standard error (RSE) values were calculated. Standardized response means were used to describe responsiveness. Pearson's correlations examined construct validity. Agreement was assessed by the Bland-Altman method. RESULTS: Both handheld dynamometry and electromechanical dynamometry demonstrated excellent test-retest reliability (ICC >0.90) and RSE (<15%). Both methods were responsive, with large postoperative standardized response means of 1.57 (handheld dynamometry) and 1.37 (electromechanical dynamometry). Pearson's correlations were moderate to strong. The Bland-Altman analysis revealed underestimation of force by handheld dynamometry, although this effect was diminished in the early postoperative period. CONCLUSIONS: Our results suggest handheld dynamometry is a promising tool for monitoring quadriceps strength in patients pre- and post-total knee arthroplasty.IMPLICATIONS FOR REHABILITATIONThis study provides evidence of high reliability and responsiveness of handheld dynamometry for assessing quadriceps strength throughout a clinically relevant time frame for patients with total knee arthroplasty.There is construct validity of handheld dynamometry for measuring quadriceps strength, with moderate to high correlations between handheld dynamometry and electromechanical dynamometry, both pre- and post-total knee arthroplasty.Rehabilitation professionals should be aware that handheld dynamometry and electromechanical dynamometry do not agree in terms of the force measurement itself; particularly at higher force values, handheld dynamometry underestimates force output relative to electromechanical dynamometry.Overall, this study supports the use of handheld dynamometry for monitoring quadriceps strength in clinical settings for patient with total knee arthroplasty.

Progressive Multicomponent Intervention for Older Adults in Home Health Settings Following Acute Hospitalization: Randomized Clinical Trial Protocol.

BACKGROUND: Hospitalization is a profound contributor to functional loss for older adults. Many modifiable risk factors (ie, weakness) may persist after hospitalization, representing portents of poor health, re-hospitalization, or death. Older adults frequently receive home health (HH) care after hospitalization to manage functional deficits that have worsened during hospital stays. However, how best to manage these deficits in HH settings has yet to be determined. OBJECTIVE: The objective is to determine if a higher intensity, progressive, multi-component (PMC) intervention, initiated upon admission to HH after an acute hospitalization, improves objectively measured and self-reported physical function more than usual care (UC) physical therapy. DESIGN: This will be a 2-arm randomized controlled clinical trial. SETTING: The setting will be participant homes. PARTICIPANTS: A total of 200 older adults with deconditioning following acute hospitalization and referred for HH physical therapy will participate. INTERVENTION: Participants will be randomized to either a PMC treatment group or a UC group and receive 12 therapy visits over a 60-day period. PMC participants will perform lower extremity resistance training at 80% of a 1-repetition maximum, task-specific activities of daily living training, along with advanced gait and balance training. PMC groups will also receive nutritional supplementation and nursing support during transition from hospital to home. The UC group will receive standard of care HH interventions. MEASUREMENTS: Physical performance, self-reported function, fatigue, and health care utilization outcomes will be measured at baseline, 30 days, 60 days, 90 days, and 180 days. All measures will be assessed by blinded study personnel. LIMITATIONS: The limitation is an inability to blind treating therapists to study allocation. CONCLUSIONS: The authors hope to determine whether higher intensity, multi-component exercise interventions improve outcomes more than UC physical therapy for older adults recovering from acute hospitalization in HH settings.