Muscle strength trajectories and their association with postoperative health-related quality of life in patients undergoing coronary artery bypass grafting surgery: a prospective cohort study.

BACKGROUND: Patients with sarcopenia have a higher risk of poor recovery after coronary artery bypass grafting (CABG). Little is known about the impact of changes in muscle strength (the primary indicator for sarcopenia) on health-related quality of life (HR-QoL). This study aimed to (1) identify subgroups with different muscle strength trajectories, (2) identify differences in preoperative risk factors among trajectory group membership, and (3) explore their prognostic value on postoperative HR-QoL in patients undergoing CABG. METHODS: In this prospective observational study 131 patients undergoing elective CABG completed grip strength tests and HR-QoL questionnaires. Latent Class Growth Mixture Modelling (LCGMM) was used to identify clinically relevant trajectories (> 5% of study population) for weight-normalised grip strength, measured at admission, 3 days, and 6 months after surgery. Differences between trajectory group membership at baseline were evaluated. The impact of trajectory group membership on postoperative HR-QoL was evaluated with multiple linear regression models. RESULTS: Due to low numbers (n = 15), female patients were excluded from LCGMM and subsequent statistical analyses. In males (n = 116), we identified two main weight-normalised grip strength trajectories: a "stable average" trajectory with a slight decline immediately post-surgery and recovery to preoperative levels (n = 85) and a "high" trajectory with a considerable immediate decline after surgery but followed towards a higher level of recovery compared to preoperative level (n = 27). The "stable average" patients were older (68 vs. 57 years; P = 0.003), had more diabetes (27% vs. 4%; P = 0.01) and had a higher BMI (27.8 vs. 24.8; P = 0.005) compared to the "high" group. After correction for age, diabetes, and baseline HR-QoL, group trajectory membership was not associated with postoperative HR-QoL, yet an increase in individual change scores of weight-normalised grip strength was associated with a better postoperative HR-QoL. We also identified one small trajectory group (n = 4, ≤ 5%). CONCLUSIONS: This study showed two relevant weight-normalised grip strength trajectories in male patients undergoing CABG, varying in important preoperative risk factors. While change scores of grip strength per weight did predict postoperative HR-QoL, the trajectory subgroups could not predict postoperative HR-QoL. Future research should focus on female patients, reacting potentially different on CABG and/or rehabilitation treatment. Trial registration NCT03774342, 12-12-2018.

A portable isometric knee extensor strength testing device: test-retest reliability and minimal detectable change scores of the Q-Force ӀӀ in healthy adults.

BACKGROUND: Although knee extensors are essential in daily activities (e.g. walking, climbing stairs), knee extensor strength is often not measured in clinical settings. Existing devices to test muscle strength are not always suitable to accurately measure the high forces of this muscle group. Therefore, a device to test muscle strength that is convenient, feasible, reliable, and valid in clinical settings is required. This study evaluated the reliability, responsiveness, and level of discomfort of the newly developed Q-Force ӀӀ (i.e. a portable device to measure isometric knee extensor strength) in healthy middle-aged and elderly adults. METHODS: Participants (n = 22) conducted two standardized test sessions on the Q-Force ӀӀ (five to ten days apart). Each session consisted of one familiarisation trial followed by three trials of peak isometric knee extension per each leg. Per trial, peak and mean knee extension force (N) and torque (Nm) were measured at 90° flexion. The level of discomfort was determined using a visual analog scale (VAS: 0-100). Intra Class Correlation (ICC, model: two-way mixed with absolute agreement), Standard Error of Measurement (SEM), and minimal detectable change (MDC) were determined. A repeated measures ANOVA was used to determine between-test variation. RESULTS: Excellent test-retest (ICC > 0.95) and inter-trial (ICC > 0.91) reliability for both legs were shown. No significant differences were found in peak and mean knee forces and torques between test and retest of both legs, indicating good test-retest reliability (P-value range: 0.360-0.538; F(1,21) range: 0.4-0.9). The SEM of the peak and mean forces and torques ranged from 28.0 to 30.4 N (6.0-6.8%) and from 9.2 to 10.4 Nm (6.4-7.7%), respectively. The MDC for these outcomes ranged respectively from 77.6 to 84.1 N (16.5-18.8%) and from 25.5 to 28.9 Nm (17.6-21.4%). The level of discomfort was low (median range: 7-10, IQR: 4-18). CONCLUSION: The portable Q-Force ӀӀ is a comfortable, responsive, and relatively cheap device with excellent test-retest reliability. This device would be potentially suitable to measure isometric knee extensor strength in clinical settings.

Early motor learning changes in upper-limb dynamics and shoulder complex loading during handrim wheelchair propulsion.

BACKGROUND: To propel in an energy-efficient manner, handrim wheelchair users must learn to control the bimanually applied forces onto the rims, preserving both speed and direction of locomotion. Previous studies have found an increase in mechanical efficiency due to motor learning associated with changes in propulsion technique, but it is unclear in what way the propulsion technique impacts the load on the shoulder complex. The purpose of this study was to evaluate mechanical efficiency, propulsion technique and load on the shoulder complex during the initial stage of motor learning. METHODS: 15 naive able-bodied participants received 12-minutes uninstructed wheelchair practice on a motor driven treadmill, consisting of three 4-minute blocks separated by two minutes rest. Practice was performed at a fixed belt speed (v = 1.1 m/s) and constant low-intensity power output (0.2 W/kg). Energy consumption, kinematics and kinetics of propulsion technique were continuously measured. The Delft Shoulder Model was used to calculate net joint moments, muscle activity and glenohumeral reaction force. RESULTS: With practice mechanical efficiency increased and propulsion technique changed, reflected by a reduced push frequency and increased work per push, performed over a larger contact angle, with more tangentially applied force and reduced power losses before and after each push. Contrary to our expectations, the above mentioned propulsion technique changes were found together with an increased load on the shoulder complex reflected by higher net moments, a higher total muscle power and higher peak and mean glenohumeral reaction forces. CONCLUSIONS: It appears that the early stages of motor learning in handrim wheelchair propulsion are indeed associated with improved technique and efficiency due to optimization of the kinematics and dynamics of the upper extremity. This process goes at the cost of an increased muscular effort and mechanical loading of the shoulder complex. This seems to be associated with an unchanged stable function of the trunk and could be due to the early learning phase where participants still have to learn to effectively use the full movement amplitude available within the wheelchair-user combination. Apparently whole body energy efficiency has priority over mechanical loading in the early stages of learning to propel a handrim wheelchair.

Evaluation of frailty in geriatric patients undergoing cardiac rehabilitation after cardiac procedure: results of a prospective, cross-sectional study.

BACKGROUND: Frailty is an indicator of a decline in quality of life and functional capacity in cardiac rehabilitation (CR) patients. Currently, there is no standardized assessment tool for frailty used in CR. The aim of this study was to determine if the Clinical Frailty Scale (CFS) is feasible for assessing frailty in CR. METHODS: Prospective, cross-sectional study within the framework of the ongoing multicenter prehabilitation study "PRECOVERY". Patients ≥75 years undergoing CR after cardiac procedure (n=122) were recruited in four German inpatient CR facilities. Assessments included: CFS, Katz-Index, hand grip strength (HGS), Short Physical Performance Battery (SPPB) and six-minute-walk test (6MWT). Outcomes were frailty (CFS≥4) and the correlation of frailty with assessments of functional capacity, activities of daily living and clinical parameters. Statistical analysis included descriptive statistics and correlations, using the spearman correlation coefficient and chi-square test to test for significance. RESULTS: Data from 101 patients (79.9±4.0 years; 63% male) were analyzed. The mean CFS score was 3.2±1.4; 41.6% were defined as frail (CFS≥4). The mean time required to assess the CFS was 0.20 minutes. The findings show that CFS correlates significantly (p<0.001) with the following factors: Katz-Index, HGS, SPPB-Score and 6MWT (r≤-0.575). In addition, CFS correlated with small to moderate effects with co-morbidities (r=0.250), as-needed medications and need for nursing assistance (r≤0.248). CONCLUSIONS: The CFS assessment can be performed in under one minute and it correlates significantly with assessments of functional capacity, activities of daily living and clinical parameters in the CR setting. TRIAL REGISTRATION: German Clinical Trials Register (DRKS; http:// www. drks. de; DRKS00032256). Retrospectively registered on 13 July 2023.

Feasibility of preoperative and postoperative physical rehabilitation for cardiac surgery patients - a longitudinal cohort study.

BACKGROUND: This study aimed to determine the feasibility of a preoperative and postoperative (in- and outpatient) physical rehabilitation program, the Heart-ROCQ-pilot program. METHODS: This cohort study included patients undergoing cardiac surgery (including coronary artery bypass graft surgery, valve surgery, aortic surgery, or combinations of these surgeries) and participated in the Heart-ROCQ-pilot program. Feasibility involved compliance and characteristics of bicycle and strength training sessions in the three rehabilitation phases. RESULTS: Of the eligible patients, 56% (n = 74) participated in the program (41% of exclusions were due to various health reasons). On average across the rehabilitation phases, the compliance rates of bicycle and strength training were 88% and 83%, respectively. Workload to heart rate (W/HR) ratio and total absolute volume load for bicycle and strength training, respectively, improved in each rehabilitation phase (P < 0.05). The W/HR-ratio was higher during the last postoperative session compared to the first preoperative session (0.48 to 0.63 W/beat, P < 0.001) and similar to the last preoperative session (0.65 to 0.64 W/beat, P < 0.497). During less than 1% of the bicycle sessions, patients reported discomfort scores of 5 to 6 (scale 0-10, with higher scores indicating a higher level). CONCLUSIONS: The Heart-ROCQ-pilot program was feasible for patients awaiting cardiac surgery. Patients were very compliant and were able to safely increase the training load before surgery and regained this improvement within eight weeks after surgery.

Prehabilitation to prevent complications after cardiac surgery - A retrospective study with propensity score analysis.

BACKGROUND: The rising prevalence of modifiable lifestyle-related risk factors (e.g. overweight and physical inactivity) suggests the need for effective and safe preoperative interventions to improve outcomes after cardiac surgery. This retrospective study explored potential short-term postoperative benefits and unintended consequences of a multidisciplinary prehabilitation program regarding in-hospital complications. METHODS: Data on patients who underwent elective cardiac surgery between January 2014 and April 2017 were analyzed retrospectively. Pearson's chi-squared tests were used to compare patients who followed prehabilitation (three times per week, at a minimum of three weeks) during the waiting period with patients who received no prehabilitation. Sensitivity analyses were performed using propensity-score matching, in which the propensity score was based on the baseline variables that affected the outcomes. RESULTS: Of 1201 patients referred for elective cardiac surgery, 880 patients met the inclusion criteria, of whom 91 followed prehabilitation (53.8% ≥ 65 years, 78.0% male, median Euroscore II 1.3, IQR, 0.9-2.7) and 789 received no prehabilitation (60.7% ≥ 65 years, 69.6% male, median Euroscore II 1.6, IQR, 1.0-2.8). The incidence of atrial fibrillation (AF) was significantly lower in the prehabilitation group compared to the unmatched and matched standard care group (resp. 14.3% vs. 23.8%, P = 0.040 and 14.3% vs. 25.3%, P = 0.030). For the other complications, no between-group differences were found. CONCLUSIONS: Prehabilitation might be beneficial to prevent postoperative AF. Patients participated safely in prehabilitation and were not at higher risk for postoperative complications. However, well-powered randomized controlled trials are needed to confirm and deepen these results.

Heart Rehabilitation in patients awaiting Open heart surgery targeting to prevent Complications and to improve Quality of life (Heart-ROCQ): study protocol for a prospective, randomised, open, blinded endpoint (PROBE) trial.

INTRODUCTION: The rising prevalence of modifiable risk factors (eg, obesity, hypertension and physical inactivity) is causing an increase in possible avoidable complications in patients undergoing cardiac surgery. This study aims to assess whether a combined preoperative and postoperative multidisciplinary cardiac rehabilitation (CR) programme (Heart-ROCQ programme) can improve functional status and reduce surgical complications, readmissions and major adverse cardiac events (MACE) as compared with standard care. METHODS AND ANALYSIS: Patients (n=350) are randomised to the Heart-ROCQ programme or standard care. The Heart-ROCQ programme consists of a preoperative optimisation phase while waiting for surgery (three times per week, minimum of 3 weeks), a postoperative inpatient phase (3 weeks) and an outpatient CR phase (two times per week, 4 weeks). Patients receive multidisciplinary treatment (eg, physical therapy, dietary advice, psychological sessions and smoking cessation). Standard care consists of 6 weeks of postsurgery outpatient CR with education and physical therapy (two times per week). The primary outcome is a composite weighted score of functional status, surgical complications, readmissions and MACE, and is evaluated by a blinded endpoint committee. The secondary outcomes are length of stay, physical and psychological functioning, lifestyle risk factors, and work participation. Finally, an economic evaluation is performed. Data are collected at six time points: at baseline (start of the waiting period), the day before surgery, at discharge from the hospital, and at 3, 7 and 12 months postsurgery. ETHICS AND DISSEMINATION: This study will be conducted according to the principles of the Declaration of Helsinki (V.8, October 2013). The protocol has been approved by the Medical Ethical Review Board of the UMCG (no 2016/464). Results of this study will be submitted to a peer-reviewed scientific journal and can be presented at national and international conferences. TRIAL REGISTRATION NUMBER: NCT02984449.

Scapular kinematics during manual wheelchair propulsion in able-bodied participants.

BACKGROUND: Altered scapular kinematics have been associated with shoulder pain and functional limitations. To understand kinematics in persons with spinal cord injury during manual handrim wheelchair propulsion, a description of normal scapular behaviour in able-bodied persons during this specific task is a prerequisite for accurate interpretation. The primary aim of this study is to describe scapular kinematics in able-bodied persons during manual wheelchair propulsion. METHODS: Sixteen able-bodied, novice wheelchair users without shoulder complaints participated in the study. Kinematic and kinetic data were collected during a standardized pose in the anatomic posture, frontal-plane arm elevation and low-intensity steady-state handrim wheelchair propulsion and upper-body Euler angles were calculated. FINDINGS: Scapulothoracic joint orientations in a static position were 36.7° (SD 5.4°), 6.4° (SD 9.1°) and 9.1° (SD 5.7°) for respectively protraction, lateral rotation and anterior tilt. At 80° of arm elevation in the frontal plane, the respective values of 33.4° (SD 8.0°), 23.9° (SD 5.4°) and 4.1° (SD 11.3°) were found. During the push phase of manual wheelchair propulsion, the mean scapular rotations were respectively 32.7° (SD 7.1°), 7.1° (SD 9.2°) and 9.8° (SD 8.3°). INTERPRETATION: The orientation of the scapula in a static pose, during arm elevation and in manual wheelchair propulsion in able-bodied participants showed similar patterns to a previous study in persons with para- and tetraplegia. These values provide a reference for the investigation of the scapular movement pattern in wheelchair-dependent persons and its relation to shoulder complex abnormalities.

Effects of visual feedback-induced variability on motor learning of handrim wheelchair propulsion.

BACKGROUND: It has been suggested that a higher intra-individual variability benefits the motor learning of wheelchair propulsion. The present study evaluated whether feedback-induced variability on wheelchair propulsion technique variables would also enhance the motor learning process. Learning was operationalized as an improvement in mechanical efficiency and propulsion technique, which are thought to be closely related during the learning process. METHODS: 17 Participants received visual feedback-based practice (feedback group) and 15 participants received regular practice (natural learning group). Both groups received equal practice dose of 80 min, over 3 weeks, at 0.24 W/kg at a treadmill speed of 1.11 m/s. To compare both groups the pre- and post-test were performed without feedback. The feedback group received real-time visual feedback on seven propulsion variables with instruction to manipulate the presented variable to achieve the highest possible variability (1st 4-min block) and optimize it in the prescribed direction (2nd 4-min block). To increase motor exploration the participants were unaware of the exact variable they received feedback on. Energy consumption and the propulsion technique variables with their respective coefficient of variation were calculated to evaluate the amount of intra-individual variability. RESULTS: The feedback group, which practiced with higher intra-individual variability, improved the propulsion technique between pre- and post-test to the same extent as the natural learning group. Mechanical efficiency improved between pre- and post-test in the natural learning group but remained unchanged in the feedback group. CONCLUSION: These results suggest that feedback-induced variability inhibited the improvement in mechanical efficiency. Moreover, since both groups improved propulsion technique but only the natural learning group improved mechanical efficiency, it can be concluded that the improvement in mechanical efficiency and propulsion technique do not always appear simultaneously during the motor learning process. Their relationship is most likely modified by other factors such as the amount of the intra-individual variability.

Low-Intensity Wheelchair Training in Inactive People with Long-Term Spinal Cord Injury: A Randomized Controlled Trial on Propulsion Technique.

OBJECTIVE: The objective of this study was to investigate the effects of a low-intensity wheelchair training on propulsion technique in inactive people with long-term spinal cord injury. DESIGN: Participants in this multicenter nonblinded randomized controlled trial were inactive manual wheelchair users with spinal cord injury for at least 10 yrs (N = 29), allocated to exercise (n = 14) or no exercise. The 16-wk training consisted of wheelchair treadmill propulsion at 30%-40% heart rate reserve or equivalent in rate of perceived exertion, twice a week, 30 mins per session. Propulsion technique was assessed at baseline as well as after 8, 16, and 42 wks during two submaximal treadmill-exercise blocks using a measurement wheel attached to a participant's own wheelchair. Changes over time between the groups were analyzed using Mann-Whitney U tests on difference scores (P < 0.05/3). RESULTS: Data of 16 participants could be analyzed (exercise: n = 8). Significant differences between the exercise and control groups were only found in peak force after 8 wks (respective medians, -20 N vs. 1 N; P = 0.01; r(u) = 0.78). CONCLUSIONS: Significant training effects on propulsion technique were not found in this group. Perhaps, substantial effects require a higher intensity or frequency. Investigating whether more effective and feasible interventions exist might help reduce the population's risk of upper-body joint damage during daily wheelchair propulsion.