Usability and preliminary effectiveness of an app-based physical activity and education program for people with hip or knee osteoarthritis - a pilot randomized controlled trial.

BACKGROUND: Hip and knee osteoarthritis (OA) are highly prevalent worldwide. The guidelines recommend physical activity and education as the core treatments for osteoarthritis. Digital health has the potential to engage people in physical activity and disease management. Therefore, we conducted a pilot trial to assess the usability and preliminary effectiveness of an app-based physical activity and education program (Join2Move) compared to usual care for people with hip and/or knee OA in Germany. METHODS: A randomized controlled pilot study was conducted. Individuals with diagnosed or self-reported knee and hip OA were included. Allocation to the intervention or control group was randomized. The intervention group received the Join2Move program. The Join2Move program was previously developed as a website and evaluated in the Netherlands. For the current study, the program was translated and adapted to the German context and adjusted from a website to an app. The control group received usual care. The primary outcomes were usability and preliminary effectiveness (pain and physical functioning). Measurements were taken at baseline and at twelve weeks. The data analysis was performed using SPSS (IBM SPSS Statistics 29.0). RESULTS: Sixty participants, with a mean age of 61.9 (SD ± 7.2) years, were allocated to the intervention (n = 32) or the control group (n = 28) and included in the analysis. The majority of participants had knee OA (68%), and 12% had hip and knee OA. The dropout rate was n = 11 (18%). No adverse events were reported. Usability was rated as acceptable (mean System Usability Scale = 71.3/100) with a wide range (32.5 to 100). Statistically significant between-group differences were found only for pain (mean difference 8.52 (95% CI 1.01 to 16.04), p = 0.027). CONCLUSIONS: Join2Move demonstrated acceptable usability. The preliminary results of the pilot trial indicate the potential of a stand-alone app for the treatment of patients with hip or knee OA. However, the acceptable usability of Join2Move limits its recommendation for everyone. There appears to be room for improvement in app usability and in identifying patients for whom the app is suitable and the right time to use a stand-alone app. TRIAL REGISTRATION: German Clinical Trials Register DRKS00027164 .

[Effects of Vibrax (Mechanical Vibrations) on the Arterial Blood Gases of Patients in the Intensive Care Unit after Cardiac Surgery]. / Effekte der Vibraxanwendung (mechanische Vibration) auf die Blutgaswerte von Patienten auf der Intensivstation nach einem kardiochirurgischen Eingriff.

OBJECTIVE: Respiratory physiotherapy is an integral part of the care of patients in intensive care units (ICU) after cardiac surgery. One of the most commonly used techniques in ICU to prevent pulmonary complications are mechanical vibrations, which can be applied with a tool called Vibrax.The aim of this study was to investigate the effects of Vibrax (mechanical vibrations) on the arterial blood gases of patients in ICU during the 1. or 2. day after cardiac surgery. METHODS: A randomized controlled pilot study was conducted with 23 patients. The participants of the control group (CG) received a cardiovascular training with mobilization to the edge of the bed and active breathing exercises. On the patients of the intervention group (IG) additionally Vibrax was applied for 5 minutes. As primary outcome parameter the PaO2/FiO2 ratio was measured. RESULTS: In the CG no significant changes over time were observed (p ≥ 0.06). The IG showed a significant (p = 0.009) increase in the PaO2/FiO2 ratio from before the physiotherapy intervention (M = 296.52, SE = 34.94 mmHg) to 60 minutes after completion of the physiotherapy intervention (M = 331.39, SE = 48.14 mmHg). There was no significant difference between the CG and IG at any measuring time (p ≥ 0.09). CONCLUSION: The results of this pilot study indicate that the application of Vibrax has positive effects on the arterial blood gases of patients in ICU on the 1. or 2. day after cardiac surgery. But whether the effects are clinically relevant could not be clarified.

The intra- and inter-observer reliability of a novel protocol for two-point discrimination in individuals with chronic low back pain.

Two-point discrimination is measured as an indicator of cortical reorganisation in musculoskeletal medicine. Nevertheless, data are lacking for the reliability of this measure in patients with non-specific chronic low back pain (NSCLBP). We aimed to quantify the intra- and inter-observer reliability of a novel protocol for measuring two-point discrimination in these patients. 35 participants (12 males, 23 females, mean age 52, SD 15 years) with NSCLBP were recruited. Three clinicians made 14 consecutive measurements of two-point discrimination with callipers. One of these clinicians repeated the assessment protocol within 7 d. During each measurement, the calliper width was widened in 5 mm increments until participants could consistently identify two points. Intra- and inter-observer agreement was quantified using mean difference, within-subject SD and limits of agreement (LOA). After using the first measurement for familiarisation, the mean of measurements 2-5 within an assessment resulted in the optimum compromise between clinic time constraints and acceptable intra-observer reliability; the within-subjects SD being 7.5 mm (LOA: 20.8 mm). Inter-observer reliability was generally poorer; requiring the mean of measurements 2-9 within an assessment for a similar within-subjects SD of 8.6 mm (LOA: 23.7 mm). It was estimated that these within-subjects SDs were small enough for a clinically-important change to be detected with a feasible sample size in future studies. The intra-observer reliability of our assessment protocol is acceptable for detecting a clinically relevant difference in two-point discrimination for future research purposes. Nevertheless, individual patient measurement variability is relatively high, especially between different clinicians.

[German version of the de Morton mobility index. First clinical results from the process of the cross-cultural adaptation]. / Deutsche Version des De Morton Mobility Index. Erste klinische Ergebnisse aus dem Prozess der interkulturellen Adaptation.

BACKGROUND: The English version of the de Morton Mobility Index (DEMMI) enables allied health professions in an inpatient setting to assess the mobility of geriatric patients in a reliable, valid, easy and fast way, without showing any floor or ceiling effects. The aim of this study was the DEMMI's cross-cultural adaption into German language with further analysis of some of its psychometric properties based on this process. MATERIAL AND METHODS: Translation was done in a multistage procedure following international recommendations. Within clinical pilot testing the DEMMI was routinely applied over a period of 3 weeks in a geriatric hospital. User experiences were evaluated in a qualitative way and DEMMI test results were analyzed with the focus on practicability and responsiveness. RESULTS: A German DEMMI version has been translated and performed with 133 patients. The test takes approximately 10 min to administer, is save and easy to use and does not show any floor or ceiling effects. The DEMMI is valid for the whole mobility spectrum, that is why mobility changes can be realized sufficiently in contrast to the Timed Up And Go Test. CONCLUSION: The DEMMI is already applicable in the German-speaking world. However, further research on its validity and reproducibility are desirable.

[Recommendation of an assessment protocol to describe geriatric inpatient rehabilitation of lower limb mobility based on ICF: an interdisciplinary consensus process]. / Empfehlungen für die Durchführung des motorischen Assessments der unteren Extremität zur ICF-basierten Verlaufsbeurteilung der Mobilität in der stationären geriatrischen Rehabilitation: Bericht eines interdisziplinären Konsensusprozesses.

Because of the growing demand of geriatric rehabilitation, objective and clear indication decisions are needed with respect to limited financial resources. The aim of an interdisciplinary consensus group was to critically evaluate the most commonly used tests of functional performance of the lower limbs and to recommend useful tests to document progress of inpatient rehabilitation. Assessment of standing, walking, walking with a dual-task, sit-to-stand transfer, lying-to-sit-to-stand transfer, and stair climbing were recommended to document functional performance of the lower limbs and to describe rehabilitation targets. Future research is needed, because reasonably validated assessment tools do not exist for all of these domains. In addition to a standardized assessment of physical capacity, physical activity and participation with regard to the International Classification of Functioning, Disability, and Health (ICF) context have to be assessed. Body fixed sensors seem to be a promising assessment tool to objectively document progress in rehabilitation.

Improvements in balance after total hip replacement.

We have investigated whether control of balance is improved during stance and gait and sit-to-stand tasks after unilateral total hip replacement undertaken for osteoarthritis of the hip. We examined 25 patients with a mean age of 67 years (sd 6.2) before and at four and 12 months after surgery and compared the findings with those of 50 healthy age-matched control subjects. For all tasks, balance was quantified using angular measurements of movement of the trunk. Before surgery, control of balance during gait and sit-to-stand tasks was abnormal in patients with severe osteoarthritis of the hip, while balance during stance was similar to that of the healthy control group. After total hip replacement, there was a progressive improvement at four and 12 months for most gait and sit-to-stand tasks and in the time needed to complete them. By 12 months, the values approached those of the control group. However, trunk pitch (forwards-backwards) and roll (side-to-side) velocities were less stable (greater than the control) when walking over barriers as was roll for the sit-to-stand task, indicative of a residual deficit of balance. Our data suggest that patients with symptomatic osteoarthritis of the hip have marked deficits of balance in gait tasks, which may explain the increased risk of falling which has been reported in some epidemiological studies. However, total hip replacement may help these patients to regain almost normal control of balance for some gait tasks, as we found in this study. Despite the improvement in most components of balance, however, the deficit in the control of trunk velocity during gait suggests that a cautious follow-up is required after total hip replacement regarding the risk of a fall, especially in the elderly.

Spatio-temporal separation of roll and pitch balance-correcting commands in humans.

This study was designed to provide evidence for the hypothesis that human balance corrections in response to pitch perturbations are controlled by muscle action mainly about the ankle and knee joints, whereas balance corrections for roll perturbations are controlled predominantly by motion about the hip and lumbro-sacral joints. A dual-axis rotating support surface delivered unexpected random perturbations to the stance of 19 healthy young adults through eight different directions in the pitch and the roll planes and three delays between pitch and roll directions. Roll delays with respect to pitch were no delay, a short 50-ms delay of roll with respect to pitch movements, (chosen to correspond to the onset time of leg muscle stretch reflexes), and a long 150-ms delay between roll and pitch movements (chosen to shift the time when trunk roll velocity peaks to the time when trunk peak pitch velocity normally occurs). Delays of stimulus roll with respect to pitch resulted in delayed roll responses of the legs, trunk, arms, and head consistent with stimulus delay without any changes in roll velocity amplitude. Delayed roll perturbations induced only small changes in the pitch motion of the legs and trunk; however, major changes were seen in the time when roll motion of the trunk was arrested. Amplitudes and directional sensitivity of short-latency (SL) stretch reflexes in ankle muscles were not altered with increasing roll delay. Small changes to balance correcting responses in ankle muscles were observed. SL stretch reflexes in hip and trunk muscles were delayed, and balance-correcting responses in trunk muscles became split into two distinct responses with delayed roll. The first of these responses was small and had a directional responsiveness aligned more along the pitch plane. The main, larger, response occurred with an onset and time-to-peak consistent with the delay in trunk roll displacement and its directional responsiveness was roll oriented. The sum of the amplitudes of these two types of balance-correcting responses remained constant with roll delay. These results support the hypothesis that corrections of the body's pitch and roll motion are programmed separately by neural command signals and provide insights into possible triggering mechanisms. The evidence that lower leg muscle balance-correcting activity is hardly changed by delayed trunk roll also indicates that lower leg muscle activity is not predominant in correcting roll motion of the body. Lower leg and trunk muscle activity appears to have a dual action in balance corrections. In trunk muscles the main action is to correct for roll perturbations and the lesser action may be an anticipatory stabilizing reaction for pitch perturbations. Likewise, the small changes in lower leg muscle activity may result from a generalized stabilizing reaction to roll perturbations, but the main action is to correct for pitch perturbations.

Compensation for rotational malalignment after intramedullary nailing for femoral shaft fractures. An analysis by plantar pressure measurements during gait.

INTRODUCTION: Even though rotational malalignment due to a femoral shaft fracture leads to clinical complaints, a large number of patients may have none of significance. The ability to compensate may play a role. The purpose of this study is to give insight into aspects of compensatory gait of patients with a femoral malrotation and the relation with clinical complaints. METHODS: In a cross-sectional laboratory setting, foot-progression angles (FPA) during gait were measured using a foot scan device. Results were related to CT determined femoral torsion and clinical complaints. RESULTS: Patients with external (EMR) or internal malrotation (IMR) showed differences in foot-progression angles (DeltaFPA) in the same direction of their malrotation. Compared to IMR patients, EMR patients appeared to compensate less for their malrotation. No statistically significant differences were detected between these groups for absolute and relative compensation. EMR patients scored worse at the Oxford 12-item and WOMAC score and experienced more problems executing demanding activities than do patients without malrotation. Correlations were found between Oxford 12-item and WOMAC score and relative compensation. CONCLUSIONS: Femoral torsion and the FPA are strongly related. All patients compensate towards normal values of FPA at their fractured side. Patients who are less able to compensate have more physical complaints. EMR patients tend to have more complaints and difficulty compensating.

The influence of artificially increased hip and trunk stiffness on balance control in man.

Lightweight corsets were used to produce mid-body stiffening, rendering the hip and trunk joints practically inflexible. To examine the effect of this artificially increased stiffness on balance control, we perturbed the upright stance of young subjects (20-34 years of age) while they wore one of two types of corset or no corset at all. One type, the "half-corset", only increased hip stiffness, and the other, the "full-corset", increased stiffness of the hips and trunk. The perturbations consisted of combined roll and pitch rotations of the support surface (7.5 deg, 60 deg/s) in one of six different directions. Outcome measures were biomechanical responses of the legs, trunk, arms and head, and electromyographic (EMG) responses from leg, trunk, and upper arm muscles. With the full-corset, a decrease in forward stabilising trunk pitch rotation compared to the no-corset condition occurred for backward pitch tilts of the support surface. In contrast, the half-corset condition yielded increased forward trunk motion. Trunk backward pitch motion after forwards support-surface perturbations was the same for all corset conditions. Ankle torques and lower leg angle changes in the pitch direction were decreased for both corset conditions for forward pitch tilts of the support-surface but unaltered for backward tilts. Changes in trunk roll motion with increased stiffness were profound. After onset of a roll support-surface perturbation, the trunk rolled in the opposite direction to the support-surface tilt for the no-corset and half-corset conditions, but in the same direction as the tilt for the full-corset condition. Initial head roll angular accelerations (at 100 ms) were larger for the full-corset condition but in the same direction (opposite platform tilt) for all conditions. Arm roll movements were initially in the same direction as trunk movements, and were followed by large compensatory arm movements only for the full-corset condition. Leg muscle (soleus, peroneus longus, but not tibialis anterior) balance-correcting responses were reduced for roll and pitch tilts under both corset conditions. Responses in paraspinals were also reduced. These results indicate that young healthy normals cannot rapidly modify movement strategies sufficiently to account for changes in link flexibility following increases in hip and trunk stiffness. The changes in leg and trunk muscle responses failed to achieve a normal roll or pitch trunk end position at 700 ms (except for forward tilt rotations), even though head accelerations and trunk joint proprioception seemed to provide information on changed trunk movement profiles over the first 300 ms following the perturbation. The major adaptation to stiffness involved increased use of arm movements to regain stability. The major differences in trunk motion for the no-corset, half-corset and full-corset conditions support the concept of a multi-link pendulum with different control dynamics in the pitch and roll planes as a model of human stance. Stiffening of the hip and trunk increases the likelihood of a loss of balance laterally and/or backwards. Thus, these results may have implications for the elderly and others, with and without disease states, who stiffen for a variety of reasons.

Reflex responses in the lower leg following landing impact on an inverting and non-inverting platform.

In the lower leg, landing after a jump induces reflexes, the role of which is not well understood. This is even more so for reflexes following landing on inverting surfaces. The latter condition is of special interest since ankle inversion traumata are one of the most common injuries during sport. Most studies have investigated ankle inversions during a static standing condition. However, ankle injuries occur during more dynamic activities such as jumping. Therefore, the present study aimed at reproducing these situations but in a completely safe setting. EMG responses were recorded after landing on an inverting surface, which caused a mild ankle inversion of 25 deg of rotation (in a range sufficient to elicit reflexes but safe enough to exclude sprains). The results are compared with data from landing on a non-inverting surface to understand the effect of the inversion. In general, landing on the platform resulted in short and long latency responses (SLR and LLR) in triceps surae (soleus, gastrocnemius medialis and lateralis) and peroneal muscles (long and short peroneal) but not in the tibialis anterior muscle. Landing on the inverting platform caused significant LLRs in the peroneal muscles (which underwent the largest stretch) but not in the triceps muscles. Conversely, landing on a non-inverting platform induced larger SLRs in triceps than in the peroneal muscles. Although the peroneal LLRs thus appeared to be selectively recruited in an inverting perturbation, their role during such perturbations should be limited since the latency of these responses was about 90 ms while the inversion lasts only 42 ms. The SLRs, if present, had an onset latency of around 44 ms. In the period following the inversion, however, the responses may be important in preventing further stretch of these muscles.

Mechanically induced ankle inversion during human walking and jumping.

A new method to study sudden ankle inversions during human walking and jumping is presented. Ankle inversions of 25 degrees were elicited using a box containing a trap door. During the gait task, subjects walked at a speed of 4 km/h. At a pre-programmed delay after left heel strike, an electromagnet released the box on the treadmill. This delay enabled the subject to step on the box without having to change the walking cadence. During the jumping task, subjects jumped from a 30 cm high platform on the box in a standardised way. In both tasks 20 stimulus and 20 control trials were presented randomly. The average tilting velocity of the trap door during the stimulus trials was 403 degrees /s during the walking task and 595 degrees /s during the jumping task. For the control trials a tilting of 0 degrees was used. With this method it is possible to evoke reproducible ankle inversions causing characteristic EMG responses in six lower leg muscles.