Benda, E.

Effectiveness of audio feedback for partial weight-bearing in and outside the hospital: A randomized controlled trial (Article)

2012-04-01T00:00:00Z

Effectiveness of audio feedback for partial weight-bearing in and outside the hospital: a randomized controlled trial. Objective: To determine the effectiveness of partial weight-bearing (PWB) training with audio feedback in patients after total hip arthroplasty (THA). Design: Randomized controlled trial. Setting: Orthopedic clinic and patients' homes. Participants: Patients (N=38) after THA with trochanteric osteotomy. Intervention: Patients were trained with (n=18) or without (n=20) audio feedback to perform PWB at a 10% body weight (BW) target load. PWB training started on day 2 or 3 postoperatively and was given once per day during the entire hospital stay. Main Outcome Measures: Mean peak load (%BW), and the percentage of steps below, equal to, and above the target load. Weight-bearing was measured using an insole pressure system on postoperative day 7 in the hospital during PWB training (condition 1 [C1]) and when patients walked unsupervised (condition 2 [C2]), and on postoperative day 21 at home (condition 3 [C3]). Results: PWB training with audio feedback resulted in better PWB (11.1% BW vs control, 21.9% BW; P=.006) at C1. The audio feedback group had more steps below the target load (21.4% vs control, 7.8%; P=.020) and fewer steps above the target load (15.6% vs control, 45.0%; P=.015). For C2 and C3, no significant differences were found between the patients receiving PWB training with and without audio feedback, for all outcome measures. Conclusions: Patients with THA who received audio feedback were able to accurately perform PWB at the prescribed target load during PWB training, but were unable to replicate the prescribed target load when they walked unsupervised in the hospital or at home.

Predictors of partial weight-bearing performance after total hip arthroplasty (Article)

2010-01-01T00:00:00Z

Abstract OBJECTIVE: To determine which patient characteristics, postoperative characteristics, and walking features influence patients' partial weight-bearing performance after total hip arthroplasty. DESIGN: A descriptive prospective study. PATIENTS: Fifty patients with total hip arthroplasty were included; partial weight-bearing was performed at a 10% body weight target load (n=33) and at a 50% body weight target load (n=17). METHODS: Patient (age, gender, body weight, upper arm muscle strength) and postoperative (pain, fatigue, anxiety) characteristics, and walking features (step frequency, total walking time, total number of steps, walking aid) were measured postoperatively on day 7 (with and without a physical therapist) and on day 21 (at home). Multilevel regression analyses were conducted to identify determinants that influence partial weight-bearing. RESULTS: Gender (female) (regression coefficient B=8.18, p=0.03) and total walking time (B=0.58, p<0.001) were positively, and pain during walking was negatively (B=-2.43, p=0.02), associated with the mean peak load. For partial weight-bearing at 10% body weight, postoperative overall anxiety (B=6.40, p=0.002) and total steps (B=0.05, p=0.02) were positively associated with the percentage of steps above the target load. For partial weight-bearing at home, postoperative overall anxiety was negatively associated with the percentage of steps above the target load (B=-5.32, p=0.001). Conclusion: Gender, pain during walking, walking time, postoperative anxiety and total number of steps influence the patient's partial weight-bearing performance.

Validity and Interobserver Reliability of Visual Observation to Assess Partial Weight-Bearing (Article)

2009-02-01T00:00:00Z

Hurkmans HL, Bussmann JB, Benda E. Validity and interobserver reliability of visual observation to assess partial weight-bearing. Objective: To determine the validity and interobserver reliability of visual observation to assess partial weight-bearing. Design: Validation and interobserver reliability study. Setting: University medical center. Participants: Patients (N=10) with a total hip arthroplasty operated 1 to 12 months prior to the study referred by 10 physical therapists (5 experienced and 5 inexperienced in training patients in partial weight-bearing). Interventions: Not applicable. Main Outcome Measures: The amount of weight-bearing assessed by visual estimation (visual analog scale score) in percentage body weight (BW). Actual weight-bearing (percentage BW) as measured with the Pedar Mobile system. The mean difference (systematic error) between visual estimation and the Pedar system and the SD of the differences (random error) were determined by the limits of agreement (LOA) method with multiple observations per subject. The intraclass correlation coefficient (ICC) was calculated as a measure for the interobserver reliability. Results: The mean difference ± SD between visual observation and the reference method was -9.5±20.1 percentage BW (95% confidence interval, -24.0 to 5.0 percentage BW) with LOA ranging from -49.8 to 30.8 percentage BW. The ICC was .57. The therapists' experience in partial weight-bearing training had no effect on the mean difference (P=.349) between the 2 methods. Conclusions: Visual observation is not a valid and reliable method to assess partial weight-bearing.

The difference between actual and prescribed weight bearing of total hip patients with a trochanteric osteotomy: long-term vertical force measurements inside and outside the hospital (Article)

2007-02-01T00:00:00Z

OBJECTIVE: To determine whether patients load the operated leg at a prescribed weight-bearing target load during postoperative recovery. DESIGN: A descriptive prospective study. SETTING: Orthopedic clinic and patients' homes. PARTICIPANTS: Fifty patients who had undergone total hip arthroplasty (THA) with trochanteric osteotomy. INTERVENTION: Patients were verbally instructed by a physical therapist to perform partial weight bearing at a 10% body weight (BW) target load (n=33) or at a 50% BW target load (n=17). MAIN OUTCOME MEASURES: Mean peak load (%BW) and percentage of patients and mean percentage of steps below, equal to, and above the target load. Weight bearing was measured when patients walked with (condition 1) and without (condition 2) a physical therapist in the hospital and walked at home (condition 3). RESULTS: The mean peak load was significantly higher than the target in the 10% BW group for all 3 conditions (condition 1, 19.2% BW; condition 2, 20.0% BW; condition 3, 26.8% BW). In the 50% BW group, the mean peak load was significantly lower than the target in conditions 1 (28.1% BW) and 2 (32.5% BW). No significant difference in weight bearing was found when walking with or without a physical therapist (change in 10% BW, -0.1% BW; change in 50% BW, -3.17% BW). At home, the mean peak load was significantly larger compared with walking without a physical therapist in the hospital (change in 10% BW, -7.0% BW; change in 50% BW, -11.5% BW). CONCLUSIONS: Partial weight bearing at a specific target load was not achieved by patients with a THA when given verbal instructions. Especially when using a low target load and when walking at home with no supervision of a physical therapist, patients loaded the operated leg higher and more frequently above the target load. Other training methods (eg, biofeedback) have to be evaluated to use as training tools for partial weight bearing at specific target loads.

Validity of the Pedar Mobile system for vertical force measurement during a seven-hour period (Article)

2006-12-01T00:00:00Z

Objective measurement of weight bearing during a long-term period can give insight into the postoperative loading of the lower extremity of orthopedic patients to avoid complications. This study investigated the validity of vertical ground reaction force measurements during a long-term period using the Pedar Mobile insole pressure system, by comparing it with a Kistler force platform. In addition, the validity of a new sensor drift correction algorithm to correct for offset drift in the Pedar signal was evaluated. Ground reaction force data were collected during dynamic and static conditions from five healthy subjects every hour for 7 h. A mean offset drift of 14.6% was found after 7 h. After applying the drift correction algorithm the Pedar system showed a high accuracy for the second peak in the ground reaction force-time curve (1.1 to 3.4% difference, p>0.05) and step duration (-2.0 to 4.4% difference, p>0.05). Less accuracy was found for the first peak in the ground reaction force-time curve (5.2 to 12.0% difference; p<0.05 for the first 3 h, p>0.05 for the last 4 h) and, consequently, in the vertical force impulse (5.5 to 11.0% difference, p>0.05). The Pedar Mobile system appeared to be a valid instrument to measure the vertical force during a long-term period when using the drift correction program described in this study.

Accuracy and repeatability of the Pedar Mobile system in long-term vertical force measurements (Article)

2006-01-01T00:00:00Z

Portable insole pressure systems can be used to measure the vertical force during long-term (hours) measurements to determine the patient's amount of weight bearing during daily activities in the hospital and at home. Especially for long-term measurements, the amount and duration of loading pressure insoles can have a large influence on the accuracy, as previous studies found a time-dependent behavior after a relatively short period (minutes) of constant loading. Therefore, this study assessed the accuracy and repeatability of a portable capacitive insole system (Pedar, Novel(GmbH)) to measure vertical force during long-term loading. Static loading experiments were performed during which the Pedar insoles were loaded with 5 and 10 N/cm2 for 7 h. Dynamic loading experiments were performed with one Pedar insole which was cyclically loaded with 300, 500 and 1000 N during two sessions of 1200 load cycles. The static and dynamic experiments were repeated 3 days later. Accuracy, due to offset drift, decreased in time during the start of the static experiments (percent error: -1.9% to 0.3% at hour 0; 26.3% to 34% at hour 7). The percent error for the dynamic experiments ranged from -16% to -19%, from -3% to -7% and from -8% to approximately 0% when the insole was loaded with 300, 500 and 1000 N, respectively. The amount of drift ranged from 12 to 62 N for the 500 and 1000 N loads, respectively. The mean day-to-day percentage difference for the static and dynamic experiments ranged from -2.3% to 0.5%, and from -2.9% to 3.0%, respectively. The results indicate that drift correction is necessary for accurate assessment of vertical force by the Pedar Mobile system to determine the amount of weight bearing during long-term measurements.

Techniques for measuring weight bearing during standing and walking (Article)

2003-08-01T00:00:00Z

OBJECTIVE: To classify and assess techniques for measuring the amount of weight bearing during standing and walking. BACKGROUND: A large variety of weight bearing measuring techniques exists. This review describes their advantages and limitations to assist clinicians and researchers in selecting a technique for their specific application in measuring weight bearing. METHODS: A literature search was performed in Pubmed-Medline, CINAHL, and EMBASE. Measurement techniques were classified in 'clinical examination', 'scales', 'biofeedback systems', 'ambulatory devices' and 'platforms', and assessed on aspects of methodological quality, application, and feasibility. RESULTS: A total of 68 related articles was evaluated. The clinical examination technique is a crude method to estimate the amount of weight bearing. Scales are useful for static measurements to evaluate symmetry in weight bearing. Biofeedback systems give more reliable, accurate and objective data on weight bearing compared to clinical examination and scales, but the high costs could limit their use in physical therapy departments. The ambulatory devices can measure weight bearing with good accuracy and reliability in the hospital and at home. Platforms have the best methodological quality, but are mostly restricted to a gait laboratory, need trained personnel, and are expensive. CONCLUSIONS: The choice of a technique largely depends upon the criteria discussed in this review; however the clinical utilisation, the research question posed, and the available budget also play a role. The new developments seen in the field of 'ambulatory devices' are aimed at extending measuring time, and improved practicality in data collection and data analysis. For these latter devices, however, mainly preliminary studies have been published about devices that are not (yet) commercially available.