Strengthening education in rehabilitation: Assessment technology and digitalization

Rehabilitation is a discipline increasingly growing around the world due to several reasons, but probably the most important one is aging population and chronicity. A need to harmonize education has been identified, and although several International organizations such as the European Union of Medical Specialists (UEMS) and the International Society of Physical Medicine and Rehabilitation (ISPRM) have defined standards, given the quick growth of new evidence and assessment methods an urge to establish new ones arises. Functional assessment and tools used to do so are key in rehabilitation processes. This comprises self-reported questionnaires, conventional clinical evaluation but more notably high technology assessment methods, such as movement analysis systems, posturography, different types of dynamometers and kinesiologic electromyography among others. More recently, a wide range of wearable systems has been introduced in patient assessment. This is generating many published protocols as well as reliability and validity studies. The objective of this narrative review is to present main assessment technologies relevant to rehabilitation, its situation of this specific area in pre-graduate and post-graduate rehabilitation educational programs, and to elaborate a formative proposal including technological foundations of assessment and also highlighting the importance of solid reliability and validity of assessment methods comprehension. The main objective of this proposal is to provide basic knowledge about rehabilitation and methodologies for outcomes evaluation, including new technologies, to all health professionals, but especially to those who work or will work in the field of Rehabilitation.

Wrist flexion and extension strength in patients with work-related chronic elbow pain: the isokinetic effort factor and its implications

BACKGROUND

The validity of isokinetic strength findings relating to forearm muscles in patients with chronic elbow pain and/or epicondylitis is not well established. Furthermore, given the nature of this disorder, ensuring maximal effort in performing the tests is an essential prerequisite. The isokinetic-based DEC parameter (defined as the difference between high- and low-velocity eccentric-to-concentric ratios of a given muscle) has been shown to efficiently detect maximal effort. The purpose of this study was therefore to assess the validity of isokinetic strength tests in patients with chronic elbow pain and/or epicondylitis.

METHODS

A cohort consisting of 44 male patients with chronic elbow pain (average evolution time, 262 ± 193.04 days) was recruited. The wrist extensor and flexor concentric and eccentric isokinetic strength of the involved and uninvolved sides was measured. The involved-uninvolved and flexor-extensor (F/E) ratios, as well as the DEC (eccentric-concentric difference), were computed based on peak moment values. Work disability and relapse within the first year were registered. In maximal performers, associations between deficits, F/E ratios, work disability, and symptom relapse were explored applying multiple comparisons.

RESULTS

Of the patients, 68.2% met the maximal-effort criteria, with the involved-side muscles being significantly weaker than their uninvolved-side counterparts in most cases. Although the mean deficit in this group was not associated with either work disability or relapse, patients with a relapse of symptoms within the first year had a significantly higher F/E ratio than those without relapse.

CONCLUSION

In patients presenting with chronic elbow pain who perform at the maximal level of effort, high wrist F/E strength ratios may predict symptom relapse.

Detection of effort maximality in adults performing isokinetic wrist flexion and extension

BACKGROUND: The difference between isokinetic eccentric to concentric strength ratios at high and low velocities (DEC) is a powerful tool for identifying submaximal effort in other muscle groups but its efficiency in terms of the wrist extensors (WE) and flexors (WF) isokinetic effort has hitherto not been studied. OBJECTIVE: The objective of the present study is to examine the usefulness of the DEC for identifying suboptimal wrist extensor and flexor isokinetic efforts. METHODS: Twenty healthy male volunteers aged 20–40 years (28.5 ± 3.2) were recruited. Participants were instructed to exert maximal and feigned efforts, using a range of motion of 20∘ in concentric (C) and eccentric (E) WE and WF modes at two velocities: 10 and 40∘/s. E/C ratios (E/CR) where then calculated and finally DEC by subtracting low velocity E/CR from high velocity ones. RESULTS: Feigned maximal effort DEC values were significantly higher than their maximal effort counterparts, both for WF and WE. For both actions, a DEC cutoff level to detect submaximal effort could be defined. The sensitivity of the DEC was 71.43% and 62.5% for WE ad WF respectively. The specificity was 100% in both cases. CONCLUSION: The DEC may be a valuable parameter for detecting feigned maximal WF and WE isokinetic effort in healthy adults.

Supraspinatus tendon transosseous vs anchor repair surgery: a comparative study of mechanical recovery in the rabbit

BACKGROUND

Supraspinatus (SSP) tendon ruptures requiring surgical repair are common. Arthroscopic suture anchor fixation has gradually replaced transosseous repair in supraspinatus tendon tear. Our objective was to compare mechanical properties between transosseous and anchor supraspinatus repair in the first 6 postoperative weeks in a rabbit model.

METHODS

One hundred and fifty-two rabbits had one supraspinatus tendon repaired either with an anchor suture 1 week after detachment or with transosseous sutures. Rabbits were euthanized at 0, 1, 2, 4 or 6 postoperative weeks. Experimental and contralateral tendons (304 tendons) were mechanically tested to failure. Data are expressed as percent of contralateral.

RESULTS

Anchor repair had higher loads to failure compared to transosseous repair, at immediate repair (week 0, 52 ± 21% vs 25 ± 17%, respectively; p = 0.004) and at 1 postoperative week (64 ± 32% vs 28 ± 10%; p = 0.003) with no difference after 2 weeks. There was no difference in stiffness. Transosseous repairs showed higher rates of midsubstance failures compared to anchor repairs at 1 (p = 0.004) and 2 postoperative weeks (p < 0.001). Both transosseous and anchor repairs restored supraspinatus mechanical properties after 4 postoperative weeks.

CONCLUSION

Anchor repair provided better initial tensile strength while transosseous repair led to a faster normalization (namely, midsubstance) of the mode of failure. Research to optimize supraspinatus repair may need to consider the advantages from both surgical approaches.

Analysis of Muscle Load-Sharing in Patients With Lateral Epicondylitis During Endurance Isokinetic Contractions Using Non-linear Prediction

The aim of this paper is to analyze muscle load-sharing in patients with Lateral Epicondylitis during dynamic endurance contractions by means of non-linear prediction of surface EMG signals. The proposed non-linear cross-prediction scheme was used to predict the envelope of an EMG signal and is based on locally linear models built in a lag-embedded Euclidean space. The results were compared with a co-activation index, a common measure based on the activation of a muscle pair. Non-linear prediction revealed changes in muscle coupling, that is load-sharing, over time both in a control group and Lateral Epicondylitis (p < 0.05), even when subjects did not report pain at the end of the exercise. These changes were more pronounced in patients, especially in the first part of the exercise and up to 50% of the total endurance time (p < 0.05). By contrast, the co-activation index showed no differences between groups. Results reflect the changing nature of muscular activation strategy, presumably because of the mechanisms triggered by fatigue. Strategies differ between controls and patients, pointing to an altered coordination in Lateral Epicondylitis.

Standard and Short RoM Isokinetic Testing: Comparative Analysis in Identifying Submaximal Shoulder External Rotator Effort

An isokinetic-related parameter termed the difference between eccentric-concentric strength ratios at two distinct test velocities (DEC) based on 60° (standard) range of motion (RoM) has been proven to be highly efficient detecting feigned muscular efforts. This study aimed to verify whether a DEC derived from a much shorter test RoM (20°) was equally useful than a long RoM-derived one. Eighteen healthy men (32.4 ± 6.4 years old) took part in a study focusing on shoulder external rotation isokinetic strength. Participants performed a genuine shoulder external rotator maximal effort (eight pairs of concentric and eccentric contractions at high and low velocities at short and long RoM) and then instructed to feign maximal effort. Contraction velocities were adjusted accordingly by applying a 1:4 gradient and peak moments registered. Both condition DEC was then calculated by subtracting the eccentric and concentric strength ratios at low velocities from those at high velocities. DEC scores in the feigned effort were significantly higher than maximal effort ones in both conditions in men. It enabled the setting of specific cutoff levels for separating the efforts. Both approaches revealed a coincident sensitivity (78%) whereas short RoM showed an even higher specificity: 88% versus 78%. Thus, the short RoM protocol provides clinically acceptable detection power.

Identification of feigned maximal shoulder external rotation effort

Objective: To examine the efficiency of the difference between the isokinetic eccentric to concentric strength ratios at high and low velocities (DEC) for identifying feigned maximal shoulder external rotation effort.

Background: Previous studies have indicated that the DEC is a powerful identifier of feigned maximal effort. However comparison of maximal versus feigned maximal shoulder external rotation effort has not been undertaken. Due to the high prevalence of rotational shoulder disorders and their chronic ramifications in terms of occupational disability such a study is of specific interest.

Design: Maximal and feigned maximal shoulder external rotation isokinetic efforts were compared.

Setting: Functional evaluation unit at an occupational rehabilitation centre.

Subjects: Seventeen healthy male volunteers aged between 20 and 40 years old.

Main measure: Concentric and eccentric isokinetic tests at 30°/s and 120°/s in maximal and feigned maximal experimental conditions. DEC was calculated by subtracting the 30°/s eccentric/concentric peak torque ratios from the 120°/s ones for both experimental conditions.

Results: A case-by-case analysis revealed that the DEC scores derived from the feigned effort were significantly greater than their maximal counterparts in all cases, leading to a cut-off value (0.81) which could distinguish between maximal and feigned performances.

Conclusions: The findings indicate that the DEC is highly effective in identifying feigned shoulder external rotation effort in normal subjects.

A cross-sectional study comparing strength profile of dorsal and palmar flexor muscles of the wrist in epicondylitis and healthy men

BACKGROUND

Strength training has been proposed by several authors to treat Lateral Epicondylitis. However, there is still a lack of information concerning muscle weakness and its relationship to imbalances and fatigability of forearm muscles during dynamic conditions in subjects after epicondylitis recovery.

AIM

To analyze the relationship between lateral humeral epicondylitis, and forearm muscle strength and fatigue.

SETTING

Rehabilitation specialized center

POPULATION

Cross-sectional study in eight former epicondylitis men free of symptoms and actively working at the moment of the evaluation and eight healthy men volunteers.

METHODS

Isokinetic tests were performed at different velocities in order to assess strength in concentric and eccentric contractions. Additionally, a long-term concentric test was carried out in order to analyze strength during endurance. The following variables were analyzed: Average torque of dorsal and palmar flexors of the wrist and ratio of agonist/antagonist for non-endurance contractions; length of initial and final plateaus and the slope of average torque decay during the endurance test.

RESULTS

In both groups, average torque produced by palmar flexor muscles was higher than that produced by dorsal flexor muscles. Patients showed higher strength in palmar flexor muscles, whereas dorsal flexor strength was similar for both populations. Palmar flexor vs. dorsal flexor ratio was significantly higher in patients for eccentric contractions. Regarding fatigue, results showed that torque decreased earlier in patients. CONCLUSIONS AND CLINICAL REHABILITATION IMPACT: Both palmar flexor force and palmar/dorsal ratio in eccentric exercise were significantly higher in patients. This finding indicates a muscular imbalance in patients underlying the epicondylitis condition. Additionally, former patients fatigued earlier. Findings indicate that muscle imbalances and fatigability might be related to lateral epicondylitis. This information may be useful in the design and monitoring of programs intended for lateral epicondylitis rehabilitation. More studies are necessary to conclude if these differences are cause or consequence of the epicondylitis.

Analysis of muscle coupling during isokinetic endurance contractions by means of nonlinear prediction

Isokinetic exercises have been extensively used in order to analyze muscle imbalances and changes associated with fatigue. It is known that such changes are difficult to assess from EMG signals during dynamic contractions, especially, using linear signal processing tools. The aim of this work was to use nonlinear prediction in order to analyze muscle couplings and interactions in this context and to assess the load-sharing of different muscles during fatigue. Results show promising for detecting interaction strategies between muscles and even for the interaction between muscles and the output torque during endurance tests.

Knee isokinetic test-retest: a multicentre knee isokinetic test-retest study of a fatigue protocol

AIM

The aim of this study was to establish the test-retest reliability of a knee extensor and flexor muscle fatigue protocol using a biodex system 3 isokinetic dynamometer.

METHODS

Three-outpatient Rehabilitation Departments undertook the study. Fatigue was evaluated in the dominant knee of 90 healthy female volunteers, non-sportswomen, aged between 20 and 40. They performed 40 consecutive concentric knee flexions and extensions, at 120 degrees /s, on a Biodex 3 isokinetic dynamometer. Two evaluations were done over a period of seven days. Analysed variables were: maximal repetition of total work, maximal work repetition number, work to body weight ratio, total work, work during first and last third of the protocol, fatigue ratio, work fatigue. Statistical analysis determined mean values, medians and box-plots. Intraclass Correlation Coefficients (ICC) (confidence interval 95 %), t-test and one-way analysis of variance (ANOVA) evaluated reliability. Difference of means (di), standard error of measurement (SEM) and 95% of interval confidence (IC di) were also calculated (P<0.05).

RESULTS

All participants completed the study. Reliability data were excellent (ICC>0.75) for total work (0.85), work during first third (0.80) and last third (0.80) in extension, and for total work in flexion. Reliability data were fair to good (ICC 0.4-0.75) for the rest of the variables. Median varied less than 20% in all cases during test-retest.

CONCLUSION

This knee fatigue protocol is reliable for flexion and extension, above all when using the total work as a variable. The desirability of multicentre studies in rehabilitation and standardisation of protocols is emphasised.

Evaluation of muscle activity and fatigue in extensor forearm muscles during isometric contractions

Work-related upper extremity disorders as epycondylitis and tendonitis are closely related to localized muscle fatigue of extensor forearm muscles. The aim of this work is to evaluate levels of activity, fatigue and interactions between the main extensor muscles of the wrist. Surface EMG signals were acquired from extensor carpi radialis (ECR), extensor digitorum comunis (EDC) and extensor carpi ulnaris (ECU) muscles during isometric contractions using linear electrode array technique. Parameters such as muscle fiber conduction velocity (CV), EMG average rectified value (ARV) and frequency parameters were estimated to study muscle activity during selective contractions, during a non specific task at different percentage of the maximum voluntary contraction (MVC) level and during a fatiguing exercise at 50% MVC. Results show that it is possible to enhance significantly ECR and ECU muscle ARV during their selective activation. Moreover, in the non selective task, ECU muscle ARV significantly decreases with respect to the other muscles with the increase of the MVC level. The activity of ECR muscle in a non specific task is predominant with respect to the other muscles at 80%MVC. EMG spectral parameters and CV show fatigue in all muscles during a sustained contraction at 50%MVC.

Activation of forearm muscles for wrist extension in patients affected by lateral epicondylitis

Work related upper extremity disorders are associated with cumulative trauma resulting from the continuous use of forearm muscles rather than from a specific incident. The aim of this work is to compare wrist extensor muscles activation between patients with lateral epicondylitis and healthy subjects. Differences can be used in the design of rehabilitation or injury prevention programs according to biomechanical deficits. Surface EMG signals from three forearm extensor muscles (Carpi Radialis-ECR, Digitorum Communis-EDC and Carpi Ulnaris-ECU) were recorded by linear electrode arrays in wrist extension as well as during selective contractions. Average Rectified Values (ARV) were calculated in order to identify the contribution of each muscle to different tasks. On the other hand, Muscle Fiber Conduction Velocity, Mean and Median Frequencies and also ARV were studied to obtain fatigue indexes related to metabolic changes in the muscles during a high force sustained contraction. Results showed muscular imbalance with lower ECR activity compensated by higher ECU activation, and higher fatigue indexes in patients with lateral epicondylitis.

Influence of walking speed on lower limb muscle activity and energy consumption during treadmill walking of hemiparetic patients

OBJECTIVE

To identify the relationship between treadmill speed and energy consumption and lower limb muscle activity in ambulatory hemiparetic patients.

DESIGN

Experimental cohort.

SETTING

Inpatient rehabilitation clinic.

PARTICIPANTS

Twenty-four ambulatory hemiparetic subjects.

INTERVENTION

Subjects walked harness-secured on the treadmill with no body-weight support at self-reported (V SAS), slow (V SAS - 25%), and fast (V SAS + 25%) speed.

MAIN OUTCOME MEASURES

Assessment of basic, limb-dependent cycle parameters, lower limb muscle activity, and energy consumption.

RESULTS

Cadence (r = .75), stride length (r = .78), relative double-support duration (r = .31), mean muscle activity of the paretic tibialis anterior (r = .12), gastrocnemius (r = .37), vastus lateralis (r =.19), rectus femoris (r = .31), and biceps femoris (r = .45) muscles, as well as heart rate (r = .54), correlated positively with treadmill speed. Mean maximum heart rate was 131 beats/min. Energy (r = -.67) and cardiac cost (r = -.55) correlated negatively with gait speed (ie, patients walked more efficiently at faster velocities). The qualitative muscle activation pattern analysis revealed earlier (more normal) onset of activation of gastrocnemius, vastus lateralis, biceps femoris, and gluteus medius.

CONCLUSIONS

Patients should try to walk fast on the treadmill, thereby facilitating relevant weight-bearing muscles and improving gait efficiency.