Using Treatment Fidelity Measures to Understand Walking Recovery: A Secondary Analysis From the Community Ambulation Project.

OBJECTIVES: Physical therapist intervention studies can be deemed ineffective when, in fact, they may not have been delivered as intended. Measurement of treatment fidelity (TF) can address this issue. The purpose of this study was to describe TF of a home-based intervention, identify factors associated with TF, and examine whether components of TF were associated with the outcome of change in 6-minute walk distance (∆6MWD). METHODS: This is a secondary analysis of community-dwelling hip fracture participants who completed standard therapy and were randomly assigned to the active intervention (Push). Push was 16 weeks of lower extremity strengthening, function, and endurance training. TF was defined as delivery (attendance rate, exercise duration) and receipt (progression in training load, heart rate reserve [HRR] during endurance training, and exercise position [exercise on floor]). The outcome was ∆6MWD. Independent variables included baseline (demographic and clinical) measures. Descriptive statistics were calculated; linear and logistic regressions were performed. RESULTS: Eighty-nine participants were included in this analysis; 59 (66%) had attendance of 75% or greater. Participants walked for 20 minutes or more for 78% of sessions. The average training load increased by 22%; the mean HRR was 35%; and 61 (69%) participants exercised on the floor for at least 75% of sessions. Regression analyses showed that a higher body mass index and greater baseline 6MWD were related to components of TF; 4 out of 5 components of TF were significantly related to ∆6MWD. The strongest TF relationship showed that those who exercised on the floor improved by 62 m (95% CI = 31-93 m) more than those who did not get on the floor. CONCLUSIONS: Measures of TF should extend beyond attendance rate. This analysis demonstrates how measures of TF, including program attendance, progression in training load, endurance duration, and exercising on the floor were significantly related to improvement in 6MWD in participants post hip fracture. IMPACT: This careful analysis of treatment fidelity assured that the intervention was delivered and received as intended. Analysis of data from a large trial with participants after hip fracture showed that regular attendance, frequent endurance training for 20 minutes, increases in lower extremity training loads, and exercising on the floor were associated with improvements in the outcome of 6-minute-walk distance. The strongest association with improvement was exercising on the floor.

Correlations among measures of knee stiffness, gait performance and complaints in individuals with knee osteoarthritis.

BACKGROUND: Stiffness is a common complaint in individuals with knee osteoarthritis and is a component of the osteoarthritis diagnosis. Yet the relationship between stiffness and function is poorly understood and methods to quantify stiffness are limited. METHODS: Using a cross-sectional observational design with 66 subjects with knee osteoarthritis, stiffness and damping coefficients were calculated from a relaxed knee oscillation procedure. Gait parameters were measured using an electronic walkway. Self-reported pain, stiffness, and function were measured with the Western Ontario and McMaster Osteoarthritis Index. Correlation and Alexander's normalized-t approximation analyses were used to assess associations among the variables. Subset analysis was performed on subjects with and without tibiofemoral joint crepitus. FINDINGS: Slight to moderate correlations existed between stiffness and damping coefficients and most gait parameters ((| r |=0.30-0.56; P<.05) and between Western Ontario and McMaster Osteoarthritis Index scores and all gait parameters (| r |=0.35-0.62; P<.05). The damping coefficient was only slightly associated with patient-rated Western Ontario and McMaster Osteoarthritis Index stiffness subscale scores. Subset analysis revealed significant correlations that differed between those with and without crepitus. INTERPRETATION: These findings suggest that laboratory measured stiffness and damping coefficients, Western Ontario and McMaster Osteoarthritis Index scores and gait-related measurements assess different aspects related to movement in individuals with knee osteoarthritis. Stiffness and damping coefficients may offer the ability to explain gait changes in the knee that are independent of a person's perceptions particularly in the early stages of the disease.

Knee joint stiffness in individuals with and without knee osteoarthritis: a preliminary study.

STUDY DESIGN: Descriptive, case-matched comparison. OBJECTIVES: To compare the knee joint stiffness and damping coefficients of individuals with knee osteoarthritis (KOA) to those of age- and gender-matched individuals without KOA. A secondary purpose was to investigate relationships between these coefficients and complaints of stiffness in individuals with KOA. BACKGROUND: KOA is a leading cause of disability, and stiffness is a common complaint in individuals with KOA. Yet the most common method of assessing knee joint stiffness is through a self-report questionnaire. METHODS AND MEASURES: Stiffness and damping coefficients at the knee were calculated in 10 volunteers (mean age +/- SD, 64.1+/-15.5 years) with KOA and compared to coefficients from age-and gender-matched individuals without KOA, collected in a previous study (mean age +/- SD, 62.1+/-13.9 years). Stiffness and damping coefficients were calculated from the angular motion of the knee during a relaxed oscillation. Spearman correlation coefficients were calculated between stiffness and damping coefficients and WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) scores for subjects with KOA. RESULTS: Independent 2-tailed t tests revealed significantly larger damping coefficients (P = .035) among those with KOA (95% CI, 0.10-2.32 Nm s/rad). Spearman rank correlations revealed a significant positive relationship (r = .85, P = .003) between the damping coefficient and the stiffness subscore of the WOMAC. CONCLUSION: This study offers preliminary data demonstrating the feasibility of measuring stiffness and damping coefficients in individuals with KOA. Additionally, the damping coefficient is increased in people with KOA when compared to age- and gender-matched individuals without KOA. The damping coefficient appears to be associated with the complaints of stiffness reported by the WOMAC.