Microcirculation in the foot is augmented by neuromuscular stimulation via the common peroneal nerve in different lower limb postures: a potential treatment for leg ulcers

AIM

Aim of the study was to examine the effects of the geko™ device (a portable electical nerve stimulator) on microcirculatory flow on the dorsum of the foot, and whether this is influenced by lower limb postures and application of a plaster cast.

METHODS

This was a cross-sectional, healthy cohort, open label, physiological response study. In 10 healthy volunteers, aged 19 to 24 years, laser Doppler fluxmetry measurements were made on the dorsum of the foot in four postures: standing (weight bearing and non-weight bearing) and supine lying (with the lower limb horizontal and then elevated). Measurements of flux were made both at rest and during stimulation with the geko™ device applied over the common peroneal nerve, at 1 Hz for 5 minutes in each posture. Repeat measurement were made after the application of a below knee plaster cast. Measures of flux were compared to basal levels assumed to be in supine with limb horizontal, with no cast and an inactive geko™ device.

RESULTS

The geko™ device was effective in increasing microcirculation on the dorsum of the foot in all four postures (mean difference =141%, 95% CI 70%-212%, P=0.001). This effect was more pronounced than that of using a plaster alone (Mean increase in flux of 73%, 95% CI 22%-125%, P=0.01) or variances due to the hydrostatic effects of different postures (mean difference 17-27.6%, P>0.05). There was a 2 to 3 fold increase in flux when stimulation was delivered in combination with the plaster cast.

CONCLUSION

Stimulation using the geko™ device augments microcirculation in the foot. The response is greater in lying and non-weight bearing than weight bearing standing but the most striking effect is when stimulation is combined with a plaster cast. The geko™ offers a potential means of promoting conditions favourable for wound healing, where treatment using compression may be contraindicated, such as arterial/mixed aetiology ulcers.

Anterior thigh composition measured using ultrasound imaging to quantify relative thickness of muscle and non-contractile tissue: a potential biomarker for musculoskeletal health

This study aimed to use ultrasound imaging to provide objective data on the effects of ageing and gender on relative thickness of quadriceps muscle and non-contractile tissue thickness (subcutaneous fat, SF, combined with perimuscular fascia). In 136 healthy males and females (aged 18-90 years n = 63 aged 18-35 years; n = 73 aged 65-90) images of the anterior thigh (dominant) were taken in relaxed supine using B-mode ultrasound imaging. Thickness of muscle, SF and perimuscular fascia were measured, and percentage thickness of total anterior thigh thickness calculated. Independent t-tests compared groups. Correlation between tissue thickness and BMI was examined using Pearson's coefficient. Muscle thickness was: 39  ±  8 mm in young males, 29  ±  6 mm in females, 25  ±  4 mm in older males and 20  ±  5 mm in females. Percentage muscle to thigh thickness was greater in young participants (p = 0.001). Percentage SF and fascia was 17  ±  6% in young and 26  ±  8% in older males, 32  ±  7% in young and 44  ±  7% in older females. BMI was similar for age and correlated moderately with non-contractile tissue (r = 0.54; p < 0.001) and poorly with muscle (r = -0.01; p = 0.93). In conclusion, this novel application of ultrasound imaging as a simple and rapid means of assessing thigh composition (relative thickness of muscle and non-contractile tissue) may help inform health status, e.g. in older people at risk of frailty and loss of mobility, and aid monitoring effects of weight loss or gain, deconditioning and exercise.

Reliability and acceptability of measuring sniff nasal inspiratory pressure (SNIP) and peak inspiratory flow (PIF) to assess respiratory muscle strength in older adults: a preliminary study

BACKGROUND

Sniff nasal inspiratory pressure (SNIP) and peak oral inspiratory flow (PIF) are portable, relatively new methods for indirect measurement of respiratory muscle strength. The reliability and acceptability of these measures were investigated in older adults.

METHODS

The study included 21 self-reported healthy adults, aged 65-84 years (mean 73.5; SD 6.4 years). Participants were tested in a sitting position on two occasions, 1 week apart. The best of three attempts for PIF measured through the mouth, and five for each nostril for SNIP were recorded. Reliability was tested using intra-class correlation coefficient (ICC), standard error of measurement, minimal detectable change (MDC) and Bland and Altman analysis. Feedback on the measures in relation to ease of completion and preference was obtained using a semi-structured interview.

RESULTS

Between-day reliability of SNIP and PIF were ICC3,1 0.76 (95 % CI 0.49-0.9) and 0.92 (0.81-0.97), respectively. Standard error of measurement for SNIP (11.94 cmH2O) and MDC (33.10 cmH2O) were at the least 61 % higher than for PIF. The participants reported difficulties in performing SNIP, rating it as being less easy and uncomfortable to perform than PIF, with a higher rate of missing data for SNIP due to participants' dislike of the test.

CONCLUSIONS

The wide range of SNIP readings, lower ICC value and negative user feedback are suggestive of a less robust and unacceptable clinical measure. PIF showed excellent reliability and acceptability and is therefore recommended for assessing inspiratory muscle strength in older people without known obstructive lung disease.

Joint loading asymmetries in knee replacement patients observed both pre- and six months post-operation

BACKGROUND

Studies have highlighted asymmetries in knee joint moments in individuals with osteoarthritis and joint replacements. However, there is a need to investigate the forces at the knee joints to establish the extent of loading asymmetries.

METHODS

Twenty healthy (mean age, 62; range, 55-79 years) and 34 pre- to post-knee arthroplasty (mean age, 64; range, 39-79 years) participants performed gait and sit-stand activities in a motion capture laboratory. Knee joint forces and moments were predicted using inverse dynamics and used to calculate peak loading and impulse data which were normalized to body weight. Comparisons were made between affected and contralateral limbs, and changes from pre- to post-knee arthroplasty.

FINDINGS

Pre-knee arthroplasty peak vertical knee forces were greater in the contralateral limb compared to the affected limb during both gait 3.5 vs. 3.2 ∗ body weight and sit-stand 1.8 vs. 1.5 ∗ body weight. During gait, peak knee adduction moment asymmetries significantly changed from pre- to post-knee arthroplasty (-0.3 to 0.8 ∗ % body weight ∗ m ∗ height), although differences in vertical knee forces remained. There were no significant changes in loading during sit-stand from pre- to post-knee arthroplasty. The healthy participants showed no noteworthy asymmetries.

INTERPRETATION

This study showed loading asymmetries in knee forces between affected and contralateral limbs both pre- and post-knee arthroplasty. Continued over reliance of the contralateral limb could lead to pathology.

Targeted interventions for patellofemoral pain syndrome (TIPPS): classification of clinical subgroups

INTRODUCTION

Patellofemoral pain (PFP) can cause significant pain leading to limitations in societal participation and physical activity. An international expert group has highlighted the need for a classification system to allow targeted intervention for patients with PFP; we have developed a work programme systematically investigating this. We have proposed six potential subgroups: hip abductor weakness, quadriceps weakness, patellar hypermobility, patellar hypomobility, pronated foot posture and lower limb biarticular muscle tightness. We could not uncover any evidence of the relative frequency with which patients with PFP fell into these subgroups or whether these subgroups were mutually exclusive. The aim of this study is to provide information on the clinical utility of our classification system.

METHODS AND ANALYSIS

150 participants will be recruited over 18 months in four National Health Services (NHS) physiotherapy departments in England.

INCLUSION CRITERIA

adults 18-40 years with PFP for longer than 3 months, PFP in at least two predesignated functional activities and PFP elicited by clinical examination.

EXCLUSION CRITERIA

prior or forthcoming lower limb surgery; comorbid illness or health condition; and lower limb training or pregnancy. We will record medical history, demographic details, pain, quality of life, psychomotor movement awareness and knee temperature. We will assess hip abductor and quadriceps weakness, patellar hypermobility and hypomobility, foot posture and lower limb biarticular muscle tightness. The primary analytic approach will be descriptive. We shall present numbers and percentages of participants who meet the criteria for membership of (1) each of the subgroups, (2) none of the subgroups and (3) multiple subgroups. Exact (binomial) 95% CIs for these percentages will also be presented.

ETHICS AND DISSEMINATION

This study has been approved by National Research Ethics Service (NRES) Committee North West-Greater Manchester North (11/NW/0814) and University of Central Lancashire (UCLan) Built, Sport, Health (BuSH) Ethics Committee (BuSH 025). An abstract has been accepted for the third International Patellofemoral Pain Research Retreat, Vancouver, September 2013.

Handgrip and quadriceps muscle endurance testing in young adults

Background

Grip strength is widely used for estimating whole body strength but there is a lack of information relating to grip endurance. Comparison between endurance of different muscle groups has received little attention. The main aim of the present study was to determine the endurance characteristics of hand grip and quadriceps muscles in healthy young adults and then to examine the association between fatigability of the two muscle groups.

Methods

Twenty one healthy participants (8 males and 13 females) aged 18–35 years were studied. A maximal intermittent endurance test, consisting of 12 isometric contractions held for 3 seconds separated by 5 second rest periods, was utilised to measure muscle endurance. A Biodex isokinetic dynamometer and Jamar dynamometer were used to assess quadriceps and hand grip respectively. The mean of first (M₁) and last (M₂) three repetitions was calculated. Fatigue index values were calculated for both muscle groups by the 1st peak torque (PT) minus the last (12th) PT, divided by the 1st PT multiplied by 100.

Results

Quadriceps torque (M₁:197.3 ± 65.2 Nm; M₂:163.1 ± 47.6 Nm) and grip strength (M₁:33.6 ± 9.9 Kg; M₂:25.2 ± 8.1 Kg) both declined significantly during the 12 repetitions (p < 0.05). Hand grip showed a significantly higher mean fatigue index of 30% compared to 18% in the quadriceps (p < 0.05).

Conclusions

Quadriceps showed better fatigability than hand grip. The findings therefore indicate caution against using grip endurance as a surrogate measure of quadriceps endurance. Further research is warranted to confirm observed differences between genders and to study endurance in different age groups.

Neuromuscular electrostimulation viathe common peroneal nerve promotes lower limb blood flow in a below-kneecast: A potential for thromboprophylaxis

Objectives

We aimed to examine the characteristics of deep venous flow in the leg in a cast and the effects of a wearable neuromuscular stimulator (geko; FirstKind Ltd) and also to explore the participants’ tolerance of the stimulator.

Methods

This is an open-label physiological study on ten healthy volunteers. Duplex ultrasonography of the superficial femoral vein measured normal flow and cross-sectional area in the standing and supine positions (with the lower limb initially horizontal and then elevated). Flow measurements were repeated during activation of the geko stimulator placed over the peroneal nerve. The process was repeated after the application of a below-knee cast. Participants evaluated discomfort using a questionnaire (verbal rating score) and a scoring index (visual analogue scale).

Results

The geko device was effective in significantly increasing venous blood flow in the lower limb both with a plaster cast (mean difference 11.5 cm/sec^-1; p = 0.001 to 0.13) and without a plaster cast (mean difference 7.7 cm/sec^-1; p = 0.001 to 0.75). Posture also had a significant effect on peak venous blood flow when the cast was on and the geko inactive (p = 0.003 to 0.69), although these differences were less pronounced than the effect of the geko (mean difference 3.1 cm/sec^-1 (-6.5 to 10)). The geko device was well tolerated, with participants generally reporting only mild discomfort using the device.

Conclusion

The geko device increases venous blood flow in the lower limb, offering a potential mechanical thromboprolylaxis for patients in a cast.

Cite this article: Bone Joint Res 2013;2:179–85.

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.

Proximal interphalangeal joint replacement in patients with arthritis of the hand: a meta-analysis

We systematically reviewed all the evidence published in the English language on proximal interphalangeal joint (PIPJ) replacement, to determine its effectiveness on the function of the hand and the associated post-operative complications. Original studies were selected if they reported clinical outcome with a minimum of one year's follow-up. Quality was assessed using the Cowley systematic review criteria modified for finger-joint replacements. Of 319 articles identified, only five were adequately reported according to our quality criteria; there were no randomised controlled trials. PIPJ replacements had a substantial effect size on hand pain of -23.2 (95% confidence interval (CI) -27.3 to -19.1) and grip strength 1.2 (95% CI -10.7 to 13.1), and a small effect on range of movement 0.2 (95% CI -0.4 to 0.8). A dorsal approach was most successful. Post-operative loosening occurred in 10% (95% CI 3 to 30) of ceramic and 12.5% (95% CI 7 to 21) of pyrocarbon replacements. Post-operative complications occurred in 27.8% (95% CI 20 to 37). We conclude that the effectiveness of PIPJ replacement has not been established. Small observational case studies and short-term follow-up, together with insufficient reporting of patient data, functional outcomes and complications, limit the value of current evidence. We recommend that a defined core set of patients, surgical and outcome data for this intervention be routinely and systematically collected within the framework of a joint registry.

Cost of healthcare for patients with migraine in five European countries: results from the International Burden of Migraine Study (IBMS)

Migraine is a disabling neurological disease that affects 14.7 % of Europeans. Studies evaluating the economic impact of migraine are complex to conduct adequately and with time become outdated as healthcare systems evolve. This study sought to quantify and compare direct medical costs of chronic migraine (CM) and episodic migraine (EM) in five European countries. Cross-sectional data collected via a web-based survey were screened for migraine and classified as CM (≥15 headache days/month) or EM (<15 headache days/month), and included sociodemographics, resource use data and medication use. Unit cost data, gathered using publicly available sources, were analyzed for each type of service, stratified by migraine status. Univariate and multivariate log-normal regression models were used to examine the relationship between various factors and their impact on total healthcare costs. This economic analysis included data from respondents with migraine in the UK, France, Germany, Italy, and Spain. CM participants had higher level of disability and more prevalent psychiatric disorders compared to EM. CM participants had more provider visits, emergency department/hospital visits, and diagnostic tests; the medical costs were three times higher for CM than EM. Per patient annual costs were highest in the UK and Spain and lower in France and Germany. CM was associated with higher medical resource use and total costs compared to EM in all study countries, suggesting that treatments that reduce headache frequency could decrease the clinical and economic burden of migraine in Europe. Comparing patterns of care and outcomes among countries may facilitate the development of more cost-effective care, and bring greater recognition to patients affected by migraine.

Quadriceps muscle tone, elasticity and stiffness in older males: reliability and symmetry using the MyotonPRO

BACKGROUND

The MyotonPRO (Myoton Ltd; London) is a new portable device for measuring muscle mechanical properties (e.g. tone) and its reliability has yet to be established. Little is known about between-limb symmetry of mechanical properties in healthy older people, despite symmetry often being used as a measure of unilateral abnormalities in clinical assessment. Since quadriceps is important for mobility, it was selected for the present study.

AIMS

To investigate: (i) between-day intra-rater reliability of a novice user of MyotonPRO; (ii) between-side symmetry of mechanical properties of quadriceps in older males.

METHODS

Twenty healthy, community dwelling, right-lower-limb-dominant males (mean age 71.7, range 65-82 years) were studied. With the participant in relaxed supine lying, the MyotonPRO applied two consecutive sets of 10 taps to induce muscle oscillations of rectus femoris, from which measurements of decrement (elasticity), frequency (tone), and stiffness were obtained. Tests were performed on two occasions at the same time and day of the week, one week apart.

RESULTS

Repeated measurements had very high within-day (intraclass correlation coefficient, ICC 3,1>0.90) and high between-day (ICC 3,2>0.70; mean of two measurement sets) reliability. There was no statistically significant difference between muscle mechanical properties of the dominant and non-dominant muscles (<2.5% difference; p>0.05), thereby indicating symmetry.

CONCLUSIONS

High intra-rater reliability was established for MyotonPRO measurements of quadriceps in healthy older males, which were symmetrical between sides. These findings indicate that larger studies are warranted to establish normal reference ranges of data with which to compare patients with muscle abnormalities.