Daily physical activities of patients with chronic pain or fatigue versus asymptomatic controls. A systematic review

Objective: To gain an insight into the daily physical activity levels of patients with chronic pain or fatigue compared with asymptomatic controls.

Data sources: MEDLINE, EMBASE, PsycINFO, Picarta, Cochrane Database of Systematic Reviews, reference tracking and a manual search of relevant journals.

Review methods: A systematic, computerized database search of the medical databases up to September 2006 was performed. In addition, a hand search of relevant journals was carried out. Appropriate studies reported on the daily physical activities of adult patients with chronic pain or fatigue and included an asymptomatic control group. Two reviewers independently carried out methodological quality assessment and data extraction. A qualitative analysis was performed.

Results: Twelve studies were included, involving five different syndromes. Results show large heterogeneity in methods used and syndromes investigated, which limited evidence. Eleven different methods were used to assess daily physical activities resulting in 16 different outcome parameters. There seem to be differences between the different syndromes, but results are not conclusive. Eight studies reported a lower physical activity level in patients compared with controls. There seems to be a difference in results between studies using objective versus those using subjective methods.

Conclusions: Results reported in the literature with respect to the activity level of patients with chronic pain or fatigue compared with controls were too heterogeneous to give sufficient evidence and were not conclusive.

Personalized Coaching Systems to support healthy behavior in people with chronic conditions

Chronic conditions cannot be cured but daily behavior has a major effect on the severity of secondary problems and quality of life. Changing behavior however requires intensive support in daily life, which is not feasible with a human coach. A new coaching approach - so-called Personal Coaching Systems (PCSs) - use on-body sensing, combined with smart reasoning and context-aware feedback to support users in developing and maintaining a healthier behavior. Three different PCSs will be used to illustrate the different aspects of this approach: (1) Treatment of neck/shoulder pain. EMG patterns of the Trapezius muscles are used to estimate their level of relaxation. Personal vibrotactile feedback is given, to create awareness and enable learning when muscles are insufficiently relaxed. (2) Promoting a healthy activity pattern. Using a 3D accelerometer to measure activity and a smartphone to provide feedback. Timing and content of the feedback are adapted real-time, using machine-learning techniques, to optimize adherence. (3) Management of stress during daily living. The level of stress is quantified using a personal model involving a combination of different sensor signals (EMG, ECG, skin conductance, respiration). Results show that Personal Coaching Systems are feasible and a promising and challenging way forward to coach people with chronic conditions.

Motor control retraining exercises for shoulder impingement: effects on function, muscle activation, and biomechanics in young adults

OBJECTIVE

Evidence for effective management of shoulder impingement is limited. The present study aimed to quantify the clinical, neurophysiological, and biomechanical effects of a scapular motor control retraining for young individuals with shoulder impingement signs.

METHOD

Sixteen adults with shoulder impingement signs (mean age 22 ± 1.6 years) underwent the intervention and 16 healthy participants (24.8 ± 3.1years) provided reference data. Shoulder function and pain were assessed using the Shoulder Pain and Disability Index (SPADI) and other questionnaires. Electromyography (EMG) and 3-dimensional motion analysis was used to record muscle activation and kinematic data during arm elevation to 90° and lowering in 3 planes. Patients were assessed pre and post a 10-week motor control based intervention, utilizing scapular orientation retraining.

RESULTS

Pre-intervention, patients reported pain and reduced function compared to the healthy participants (SPADI in patients 20 ± 9.2; healthy 0 ± 0). Post-intervention, the SPADI scores reduced significantly (P < .001) by a mean of 10 points (±4). EMG showed delayed onset and early termination of serratus anterior and lower trapezius muscle activity pre-intervention, which improved significantly post-intervention (P < .05). Pre-intervention, patients exhibited on average 4.6-7.4° less posterior tilt, which was significantly lower in 2 arm elevation planes (P < .05) than healthy participants. Post-intervention, upward rotation and posterior tilt increased significantly (P < .05) during 2 arm movements, approaching the healthy values.

CONCLUSION

A 10-week motor control intervention for shoulder impingement increased function and reduced pain. Recovery mechanisms were indicated by changes in muscle recruitment and scapular kinematics. The efficacy of the intervention requires further examined in a randomized control trial.

Comparing VO2max determined by using the relation between heart rate and accelerometry with submaximal estimated VO2max

AIM

An exploratory study to identify parameters that can be used for estimating a subject's cardio-respiratory physical fitness level, expressed as VO2max, from a combination of heart rate and 3D accelerometer data.

METHODS

Data were gathered from 41 healthy subjects (23 male, 18 female) aged between 20 and 29 years. The measurement protocol consisted of a sub-maximal single stage treadmill walking test for VO2max estimation followed by a walking test at two different speeds (4 and 5.5 kmh-1) for parameter determination. The relation between measured heart rate and accelerometer output at different walking speeds was used to get an indication of exercise intensity and the corresponding heart rate at that intensity. Regression analysis was performed using general subject measures (age, gender, weight, length, BMI) and intercept and slope of the relation between heart rate and accelerometer output during walking as independent variables to estimate the VO2max.

RESULTS

A linear regression model using a combination of the slope and intercept parameters, together with gender revealed the highest percentage of explained variance (R2 = 0.90) and had a standard error of the estimate (SEE) of 2.052 mL O2kg-1min-1 with VO2max. Results are comparable with current commonly used sub-maximal laboratory tests to estimate VO2max.

CONCLUSION

The combination of heart rate and accelerometer data seems promising for ambulant estimation of VO2max-.

Foot and ankle joint kinematics in rheumatoid arthritis cannot only be explained by alteration in walking speed

Rheumatoid arthritis (RA) manifests itself in the foot and ankle of RA patients. The foot and ankle joint kinematics of these patients differ from that of healthy subjects. However, the factors that lead to these differences are not yet fully understood. The aim of this study was to analyse the effect of walking speed and the disease process on foot and ankle joint kinematics of RA subjects. Gait recordings of 23 RA and 14 age-matched healthy subjects were performed and their foot and ankle joint kinematics were analysed during the stance phase of the gait cycle. Stance phase characteristics of the group of RA subjects and of the group of healthy subjects were compared. The healthy subjects walked at 100% (Vc), 75% (V75) and 50% (V50) of their comfortable walking speed. In a multi-level linear model significant differences between the two groups due to the factors walking speed and the disease process were analysed. The ankle dorsi-flexion, medial arch and hallux abduction motion at single-stance and toe-off were only influenced by the walking speed. The hallux maximum flexion at toe-off and the midfoot supination at single-stance were influenced by both the walking speed and the disease process. The hindfoot eversion motion at single-stance was only influenced by the disease process. In conclusion, the reduction of walking speed of RA subjects compared to healthy subjects does not explain all of the observed foot and ankle kinematics differences.

Spasticity and contractures at the wrist after stroke: time course of development and their association with functional recovery of the upper limb

Objective: To investigate the time course of development of spasticity and contractures at the wrist after stroke and to explore if these are associated with upper limb functional recovery.

Design: Longitudinal observational study using secondary data from the control group of a randomized controlled trial.

Setting: The Acute Stroke Unit at the University Hospital of North Staffordshire.

Subjects: Patients without useful arm function (Action Research Arm Test — ARAT) score of 0 within 6 weeks of a first stroke.

Main measures: Spasticity was measured by quantifying muscle activity during passively imposed stretches at two velocities. Contractures were measured by quantifying passive range of movement and stiffness. Upper limb functional movement was assessed using the ARAT. All assessments were conducted at baseline, and at 6, 12, 24 and 36 weeks after recruitment.

Results: Thirty patients (43% male, median age 70 (range 52—90) years, median time since stroke onset 3 (range 1—5) weeks) were included. Twenty-eight (92%) demonstrated signs of spasticity throughout the study period. Participants who recovered arm function (n = 5) showed signs of spasticity at all assessment points but did not develop contractures. Patients who did not recover useful arm function (n = 25) had signs of spasticity and changes associated with contracture formation at all time points tested.

Conclusion: In this group of patients who had no arm function within the first 6 weeks of stroke, spasticity was seen early, but did not necessarily hinder functional recovery. Contractures were more likely to develop in patients who did not recover arm function.

Mobile patient monitoring: the MobiHealth system

The emergence of high bandwidth public wireless networks and miniaturized personal mobile devices give rise to new mobile healthcare services. To this end, the MobiHealth system provides highly customizable vital signs tele-monitoring and tele-treatment system based on a body area network (BAN) and a mobile health care (m-health) service platform utilizing next generation public wireless networks. The developed system allows the incorporation of diverse medical sensors via wireless connections, and the live transmission of the measured vital signs to healthcare providers as well as real-time feedback to the patient. Since 2002 the system has undergone substantial development in consecutive EU and national research projects. Diverse trials with different healthcare scenarios and patient groups in different European countries have been conducted in all projects. These have been performed to test the service and the network infrastructure including its suitability for m-health applications.

Spasticity, an impairment that is poorly defined and poorly measured

Objective: To explore, following a literature review, whether there is a consistent definition and a unified assessment framework for the term `spasticity'. The congruence between the definitions of spasticity and the corresponding methods of measurement were also explored.

Data sources: The search was performed on the electronic databases Web of Science, Science Direct and MEDLINE.

Review methods: A systematic literature search of publications written in English between the years 1980 and 2006 was performed with the following keywords: spasticity and tone. The search was limited to the following keywords: stroke, hemiplegia, upper, hand and arm.

Results: Two hundred and fifty references contributed to this review (190 clinical trials, 46 literature reviews, and 14 case reports). Seventy-eight used the Lance definition; 88 equated spasticity with increased muscle tone; 78 provided no definition; and six others used their own definitions for spasticity. Most papers used a single measure and some used more than one. Forty-seven papers used neurophysiological methods of testing, 228 used biomechanical methods of measurement or assessment, 25 used miscellaneous clinical measures (e.g. spasm frequency scales) and 19 did not explicitly describe a measure.

Conclusion: The term spasticity is inconsistently defined and this inconsistency will need to be resolved. Often, the measures used did not correspond to the clinical features of spasticity that were defined within a paper (i.e. internal validity was compromised). There is need to ensure that this lack of congruence is addressed in future research.

Influence of Gravity Compensation on Muscle Activation Patterns During Different Temporal Phases of Arm Movements of Stroke Patients

Background. Arm support to help compensate for the effects of gravity may improve functional use of the shoulder and elbow during therapy after stroke, but gravity compensation may alter motor control. Objective. To obtain quantitative information on how gravity compensation influences muscle activation patterns during functional, 3-dimensional reaching movements. Methods. Eight patients with mild hemiparesis performed 2 sets of repeated reach and retrieval movements, with and without unloading the arm, using a device that acted at the elbow and forearm to compensate for gravity. Electromyographic (EMG) patterns of 6 upper extremity muscles were compared during elbow and shoulder joint excursions with and without gravity compensation. Results. Movement performance was similar with and without gravity compensation. Smooth rectified EMG (SRE) values were decreased from 25% to 50% during movements with gravity compensation in 5 out of 6 muscles. The variation of SRE values across movement phases did not differ across conditions. Conclusions. Gravity compensation did not affect general patterns of muscle activation in this sample of stroke patients, probably since they had adequate function to complete the task without arm support. Gravity compensation did facilitate active arm movement excursions without impairing motor control. Gravity compensation may be a valuable modality in conventional or robot-aided therapy to increase the intensity of training for mildly impaired patients.

Rectus femoris surface myoelectric signal cross-talk during static contractions

The clinical application of EMG requires that the recorded signal is representative of the muscle of interest and is not contaminated with signals from adjacent muscles. Some authors report that surface EMG is not suitable for obtaining information on a single muscle but rather reflects muscle group function [J. Perry, C.S. Easterday, D.J. Antonelli, Surface versus intramuscular electrodes for electromyography of superficial and deep muscles. Physical Therapy 61 (1981) 7-15]. Other authors report however, that surface EMG is adequate to determine individual muscle function, once guidelines pertaining to data acquisition are followed [D.A. Winter, A.J. Fuglevand, S.E. Archer. Cross-talk in surface electromyography: theoretical and practical estimates. Journal of Electromyography and Kinesiology 4 (1994) 15-26]. The aim of this study was to determine whether surface EMG was suitable for monitoring rectus femoris (RF) activity during static contractions. Five healthy subjects, having given written informed consent, participated in this trial. Surface and fine wire EMG from the rectus femoris and the vastus lateralis (VL) muscles were recorded simultaneously during a protocol of static contractions consisting of knee extensions and hip flexions. Ratios were used to quantify the relationship between the surface EMG amplitude value and the fine wire EMG amplitude value for the same contraction. The results showed that hip flexion contractions elicited RF activation only and that knee extension contractions elicited fine wire activity in VL only. When the relationship between RF surface and RF fine wire electrodes was compared for hip flexion and knee extension contractions, it was observed that for all subjects, there was a tendency for increased RF surface activity in the absence of RF fine wire activity during knee extensions. It was concluded that the activity recorded by the RF surface electrode arrangement during knee extension consisted of EMG from the vastii, i.e., cross-talk and that vastus intermedius was the most likely origin of the erroneous signal. Therefore it is concluded that for accurate EMG information from RF, fine wire electrodes are necessary during a range of static contractions.

Comparative assessment of study groups of elderly female computer users from four European countries: questionnaires used in the NEW study

There is a lack of consistent and comprehensive questionnaire forms for the studies of factors associated with work-related musculoskeletal disorders at the European level. One of the results of the EU-funded project, neuromuscular assessment in the elderly worker (NEW), is a set of questionnaires for the screening of musculoskeletal status and the studies of factors that are believed to affect musculoskeletal health. The questionnaires have been used among elderly women (45+) in different occupations and organisations in Denmark, The Netherlands, Sweden and Switzerland. The aim of this short communication is to present the questionnaires used in the NEW study and to evaluate the appropriateness of pooling data gathered in each participating country into a common database. It is concluded that although differences exist among the study samples, these are not of such a magnitude or pattern that data from the four groups cannot be pooled. The questionnaires are available in Danish, Dutch, English, German and Swedish.

Is rectus femoris really a part of quadriceps? Assessment of rectus femoris function during gait in able-bodied adults

There is conflicting evidence as to the precise activation pattern of the rectus femoris (RF) muscle during gait in able-bodied subjects. The aim of this study was to determine precise activation pattern of RF during gait in a healthy adult population. Surface and fine wire EMG from RF and vastus lateralis (VL) were recorded simultaneously at different walking speeds in five able-bodied subjects. The results of fine wire EMG showed that, at normal walking speed, RF was active only during the stance-to-swing transition. At faster speeds, increased levels of RF activity were seen during the same transition period. At the fastest speed, there was some activity during terminal stance, in addition to that at stance-to-swing transition, that could be attributed to rapid hip extension and thereby a rapid stretch of RF. However, the RF surface EMG signal was found to exhibit a bi-phasic pattern whilst walking at all different self-selected speeds. A burst of EMG activity recorded at initial contact on the surface signal but not on fine wire EMG, was due to cross-talk from vastus intermedius (VI). A close similarity was observed between the surface EMG patterns of VL and RF. VL surface and fine wire EMG profiles were identical for all the self-selected speeds with a main peak of activity beginning in terminal swing and ceasing in mid-stance. We conclude that RF is active only during stance-to-swing transition and the activity during swing-to-stance transition, as described in the literature, is very probably due to cross-talk.

Performance specification for lower limb orthotic devices

OBJECTIVE

To establish the range of forces and moments applied to lower limb orthoses during ambulation by routine users.

DESIGN

Well-established gait analysis techniques were used to determine the loading at the major joints. It was assumed that the joint moments were transmitted by the orthosis encompassing any particular joint. Two hundred and five assessments of 164 patients were successfully completed by a consortium of four gait laboratories in Europe. The orthosis specification and patient clinical data were also recorded.

BACKGROUND

The design and development of orthoses has occurred largely by evolution rather than by formal engineering methods. In particular, formal design has been hampered by a lack of information on the forces and moments applied during ambulation.

METHODS

A standard gait analysis procedure was employed to capture the data. In-house biomechanical models were used to calculate the joint loading. Data were normalised with respect to patient weight and leg length.

RESULTS

It was found that the median maximum normalised ankle moment transmitted by an ankle foot orthosis was 0.15 and the maximum knee moment was 0.09. The greatest moment transmitted by the hip joint of a hip knee ankle foot orthosis was also 0.09. There was a wide variation in the data due to differences in the impairments of the test subjects.

CONCLUSION

It is possible to estimate the loads transmitted by an orthosis using established gait analysis procedures without the need for load measurement transducers. There is now a need both to collect a larger representative dataset and to perform validation studies with transducers.

Three dimensional inertial sensing of foot movements for automatic tuning of a two-channel implantable drop-foot stimulator

A three dimensional inertial sensing system for measuring foot movements during gait is proposed and tested. It can form the basis for an automated tuning system for a two-channel implantable drop-foot stimulator. The foot orientation and position during the swing phase of gait can be reconstructed on the basis of three-dimensional measurement of acceleration and angular velocity, using initial and final conditions during mid-stance. The foot movements during gait of one stroke person using the implanted two-channel stimulator were evaluated for several combinations of stimulation parameters for both channels. The reconstructed foot movements during gait in this person indicated that the channel stimulating the deep peroneal nerve contributes mainly to dorsiflexion and provides some reduction of inversion seen without stimulation, while the channel activating the superficial peroneal nerve mainly provides additional reduction of inversion. This agrees with anatomical knowledge about the function of the muscles activated by both branches of the peroneal nerve. The inertial sensor method is expected to be useful for the clinical evaluation of foot movements during gait supported by the two-channel drop-foot stimulator. Furthermore, it is expected to be applicable for the automated balancing of the two stimulation channels to ensure optimal support of gait.

Sacral anterior root stimulation for bladder control in patients with a complete lesion of the spinal cord

A Finetech-Brindley bladder controller was implanted in 17 patients with a complete lesion of the spinal cord. During a microscopic procedure in the cauda equina, the sacral roots were identified and the posterior components of the S2, S3 and S4 roots were cut. The stimulator was placed intradurally around the anterior components of the S2, S3, S4 roots and the S5 root. Our patients have now been followed-up for periods varying between 1 and 6 years. In all 17 patients, the bladder capacity has been increased; 16 patients have a residual volume of less than 30 ml, urinary tract infection is rare; 12 patients are fully continent. All male patients can achieve a full sustained erection by means of the implant and 13 patients are using the implant for bowel function. The method has no significant harmful effects or complications.

Electromyogram power spectra frequencies associated with motor unit recruitment strategies

The isolated contributions of motor unit recruitment and firing rate variations to the median frequency of the electromyogram's power density spectrum were determined. Orderly stimulation of the cat gastrocnemius motor units via nerve electrodes gave rise to linearly increasing median frequency regardless of the action potential firing rate of the active motor units. Increase in the discharge rate of all the motor units resulted in nearly constant median frequency. It was concluded that the increasing average conduction velocity during motor unit recruitment is the major contributor to variations in the electromyogram median frequency. The possibility of using the median frequency as the index to identify the recruitment control strategies employed by various muscles during increasing force contraction is suggested.