Lower insulin sensitivity is related to lower relative muscle cross-sectional area, lower muscle density and lower handgrip force in young and middle aged non-diabetic men.

OBJECTIVES: This study investigated whether an association between insulin resistance (IR) and muscle parameters is appreciable in young healthy men, independent of obesity. Furthermore, markers of muscle metabolism and hormones/possible determinants, were explored. METHODS: 358 healthy young men were divided into a less and more insulin sensitive (LIS [age=33.2±5.4, BMI=23.4±2.3] and MIS [age=35.5±5.3, BMI=28.1±3.7]) group based on upper and lower quartile of HOMA-IR. Muscle cross-sectional area (CSA), -density, handgrip force, serum testosterone, estradiol, SHBG, Vitamin 25(OH)D, creatinine, IGF-1, IGFBP-3 and leptin levels were compared between these groups, correcting for differences in age, physical activity and fat mass. Correlations between HOMA-IR and these parameters, and between muscle measures and biochemical parameters, were calculated. RESULTS: LIS is related to lower relative muscle CSA, muscle density, muscle/fat CSA ratio, relative handgrip force and level of physical activity. Furthermore, lower levels in SHBG, testosterone, Vitamin 25(OH)D and higher leptin, IGF-1 and IGFBP-3 levels were observed in LIS. Bio available T, FT, TE2, FE2, bioavailable E2, serum and urinary creatinine levels did not differ between groups. CONCLUSION: Differences in muscle performance are already present in healthy men with lower insulin sensitivity and could be possibly modifiable risk factors for the development of type 2 diabetes.

Association between insulin resistance, lean mass and muscle torque/force in proximal versus distal body parts in healthy young men.

OBJECTIVES: The purpose of this study was to investigate whether there is already an association of insulin resistance (IR) with muscle mass and -force/torque in an adult population and whether this relationship is the same in distal and proximal body parts. METHODS: 358 Healthy young men were divided into a more insulin sensitive (MIS) (n=89) and a less insulin sensitive (LIS) group (n=89), respectively using lower and upper quartiles of HOMA-IR index (Homeostasis Model Assessment of IR). Muscle force/torque and lean mass, were compared between the two groups. RESULTS: LIS subjects had higher absolute thigh lean mass, but not higher thigh muscle torque, resulting in a lower torque per kg muscle. In upper arm, lean mass was higher in LIS subjects, but also absolute muscle torque resulted higher. For handgrip force, the LIS and MIS group had similar results, despite a trend towards higher forearm lean mass in LIS subjects. Lean mass % of total lean mass is lower in LIS subjects in more distal body parts. CONCLUSIONS: Already in a young healthy population, IR seems to be associated with lower force/torque per muscle mass and lower lean mass % of total lean mass predominantly in more distal body parts.

Changes in microcirculation of the trapezius muscle during a prolonged computer task.

The aim of this study is to investigate if there is a change in oxygen saturation and blood flow in the different parts of the trapezius muscle in office workers with and without trapezius myalgia during a standardized computer task. Twenty right-handed office workers participated; ten were recruited based on pain in the trapezius and ten as matching controls. Subjects performed a combination of typing and mousing tasks for 60 min at a standardized workstation. Muscle tissue oxygenation and blood flow data were collected from the upper trapezius (UT), the middle trapezius (MT) and the lower trapezius (LT), both on the left and right side at seven moments (at baseline and every tenth minute during the 1-h typing task) by use of the oxygen to see device. In all three parts of the trapezius muscle, the oxygen saturation and blood flow decreased significantly over time in a similar pattern (p < 0.001). Oxygenation of the left and right UT was significantly higher compared to the other muscle parts (p < 0.001). Oxygen saturation for the MT was significantly lower in the cases compared to the control group (p = 0.027). Blood flow of the UT on the right side was significantly lower than the blood flow on the left side (p = 0.026). The main finding of this study was that 1 h of combined workstation tasks resulted in decreased oxygen saturation and blood flow in all three parts of the trapezius muscle. Future research should focus on the influence of intervention strategies on these parameters.

Psychometric properties of a motor skill checklist for 3- to 5-year-old children.

BACKGROUND: Early identification of children with developmental co-ordination disorder is important. Teachers may be very useful in this identification process. The objective of this study was to develop a motor skill checklist (MSC) for 3- to 5-year-old children to be completed by teachers, and to establish the psychometric properties of this new instrument. METHODS: An MSC of 28 functional items was constructed in close consideration with clinical experts and teachers. In regular schools, 366 pre-school children were rated with the MSC by their teachers (n= 111). To determine test-retest reliability, each teacher completed 4 weeks later the MSC again for one randomly selected child. In 22 classes with two teachers sharing the job, both teachers were asked to fill in the questionnaire. A subgroup of children was also tested with the Movement Assessment Battery for Children (M-ABC; n= 122). All teachers were invited to complete a questionnaire to evaluate the MSC. RESULTS: The internal consistency of the MSC was high. The test-retest reliability was good. Inter-rater reliability was adequate except in the 5-year-old children. There was a strong correlation between the checklist and the M-ABC, establishing concurrent validity. Most teachers judged the MSC as easy or rather easy to complete. CONCLUSIONS: The MSC is a reliable, valid and useful instrument to identify and assess young children with motor difficulties.

Test-retest reliability of the assessment of postural stability in typically developing children and in hearing impaired children.

The purpose of this study was to establish test-retest reliability of centre of pressure (COP) measurements obtained by an AccuGait portable forceplate (ACG), mean COG sway velocity measured by a Basic Balance Master (BBM) and clinical balance tests in children with and without balance difficulties. 49 typically developing children and 23 hearing impaired children, with a higher risk for stability problems, between 6 and 12 years of age participated. Each child performed the modified Clinical Test of Sensory Interaction on Balance (mCTSIB), Unilateral Stance (US) and Tandem Stance on ACG, mCTSIB and US on BBM and clinical balance tests: one-leg standing, balance beam walking and one-leg hopping. All subjects completed 2 test sessions on 2 different days in the same week assessed by the same examiner. Among COP measurements obtained by the ACG, mean sway velocity was the most reliable parameter with all ICCs higher than 0.72. The standard deviation (SD) of sway velocity, sway area, SD of anterior-posterior and SD of medio-lateral COP data showed moderate to excellent reliability with ICCs between 0.55 and 0.96 but some caution must be taken into account in some conditions. BBM is less reliable but clinical balance tests are as reliable as ACG. Hearing impaired children exhibited better relative reliability (ICC) and comparable absolute reliability (SEM) for most balance parameters compared to typically developing children. Reliable information regarding postural stability of typically developing children and hearing impaired children may be obtained utilizing COP measurements generated by an AccuGait system and clinical balance tests.

Functional reorganization of cervical flexor activity because of induced muscle pain evaluated by muscle functional magnetic resonance imaging.

There is mounting evidence of an association between chronic neck pain and impaired cervical flexor muscle performance. It is likely that the deep cervical flexors demonstrate changes very early after the onset of pain, but evidence is currently lacking. This study investigated the effect of experimental neck muscle pain on the activation of the cervical flexor muscles during the performance of craniocervical flexion (CCF) by use of muscle functional magnetic resonance imaging. Activity of the longus colli (Lco), longus capitis (Lca) and sternocleidomastoid (SCM) muscles were investigated bilaterally and at three cervical levels (C0-C1, C2-C3 and C6-C7) in 14 healthy subjects. Measurements were performed at rest and after the performance of CCF without and with induced pain of the upper trapezius (intramuscular injection of hypertonic saline). In the non-pain condition, the Lca (p = 0.005) and Lco (p = 0.029) were significantly more active during CCF compared to SCM. In the pain condition, the activity of the Lco and Lca was reduced bilaterally and at multiple levels (p ≤ 0.009), whereas the left SCM showed increased activity at only the C6-C7 level (p ≤ 0.001). The results suggest that local excitation of nociceptive afferents causes an immediate reorganization of the cervical flexor muscle activity similar to that identified in clinical populations.

Catastrophic thinking about pain as a predictor of length of hospital stay after total knee arthroplasty: a prospective study.

This study prospectively investigates whether catastrophizing thinking is associated with length of hospital stay after total knee arthroplasty. Forty-three patients who underwent primary total knee arthroplasty were included in this study. Prior to their operation all patients were asked to complete the pain catastrophizing scale, and a Western Ontario McMaster Universities Osteoarthritis index. A multiple regression analysis identified pain catastrophizing thinking and age as predictors of hospital stay after total knee arthroplasty. Patients with a higher degree of pain catastrophizing prior to the total knee arthroplasty and those with a higher age have a significantly greater risk for a longer hospital stay. Therefore, the results of this study indicate that the pre-operative level of pain catastrophizing in patients determine, in combination with other variables, the length and inter-individual variation in hospital stay after total knee arthroplasty. Reducing catastrophizing thinking about pain through cognitive-behavioral techniques is likely to reduce levels of fear after total knee arthroplasty. As a result, pain and function immediately post-operative might improve, leading to a decrease in length of hospital stay. Although during the last decades the duration of hospital stay is significantly reduced, this study shows that this can be improved when taking into account the contribution of psychological factors such as pain catastrophizing.

MRI analysis of muscle/fat index of the superficial and deep neck muscles in an asymptomatic cohort.

All muscles of the neck have a role in motion and postural control of the cervical region. The aim of this study was to investigate the difference in muscle/fat index between (1) cervical flexors and extensors and (2) deep and superficial neck muscles. Twenty-six healthy subjects participated in the study. Magnetic resonance imaging (MRI) was used to quantify muscle fat indices in different cervical flexor and extensor muscles at the C4-C5 level. Overall, the ventral muscles had a significantly lower fat content compared with the dorsal muscles (P < or = 0.001). For the cervical extensors, significant differences between the muscle/fat index of the deep and superficial muscles were found (P < or = 0.001). For the cervical flexors, there were no significant differences between the different muscles. The higher fat content in the dorsal muscles can be explained by a discrepancy in function between the spine extensors and flexors, reflected in a different muscle fiber distribution. The rather small differences between superficial and deep neck muscles are in line with recent findings that have demonstrated that both muscles groups exhibit phasic activity during isometric muscles contractions and the presumption that there is no difference in fiber type distribution between superficial and deep neck muscles.

Does soccer participation lead to genu varum?

Little is known about the relationship between sport participation and body adaptations during growth. Our aim was to investigate whether soccer participation in youth is associated with the degree of genu varum. The design was a retrospective cohort study. Three hundred and thirty-six male soccer players, and 458 male non-soccer players (aged from 8 to 18) were recruited and included in the study. The intercondylar (IC) or intermalleolar (IM) distance were clinically measured with a specifically designed instrument. The results of this study revealed a statistically significant increase in degree of genu varum in both groups from the age of 14. However, at the age of 16-18 years a significant higher degree of genu varum was observed in the soccer players compared to the non-soccer players (P = 0.028). Intense soccer participation increases the degree of genu varum in males from the age of 16. Since genu varum predisposes to injuries, efforts to reduce the development of genu varum in male soccer players are warranted.

Falls among stroke survivors: an online survey on perceptions and approaches among physiotherapists in Flanders.

OBJECTIVE: To describe physiotherapists' perceptions of fall risk and appropriate fall prevention interventions in rehabilitating stroke patients. METHOD: A web-based survey addressed to physiotherapy units on a stroke unit, general neurology department or rehabilitation ward/centre in Flanders. RESULTS: Hospital response rate was 66.3%. Sixty-five physiotherapy units were taken into account. About 84.6% recognised falls among stroke patients as an essential problem and 73.8% thought falls interfered with the outcome. About 56.9% agreed with the need of a standardised fall assessment at the beginning of the treatment and only 36.9% reported that on their department stroke patients are screened on risk of falling. The most used fall risk assessments are: Berg Balance scale and Tinetti-test. The most popular fall prevention measures are: specific exercises for balance, gait and functional abilities (100%), informative education (92.3%) and adapting or intensifying the treatment after a fall (81.5%). CONCLUSIONS: Physiotherapy units acknowledge falls as an essential threat, implying a need for risk screening and prevention. However, results reveal that perception of the necessity of such screening is lower and that the performance is even less. This discrepancy underlines the necessity of guidelines and education of therapists working with stroke patients.

Screening the athlete's shoulder for impingement symptoms: a clinical reasoning algorithm for early detection of shoulder pathology.

Chronic shoulder pain and dysfunction are common complaints among overhead athletes seeking care from physical medicine and rehabilitation. Impingement is a frequently described pathological condition in the overhead athlete. Impingement symptoms may be the result of rotator cuff pathology, shoulder instability, scapular dyskinesis or muscle dysfunction, biceps pathology, SLAP lesions and chronic stiffness of the posterior capsule. At present, numerous different shoulder tests have been described in literature and discussed with respect to their individual diagnostic accuracy. However, in view of the number of shoulder tests, it is often a challenge for the clinician to select the appropriate tests for diagnosing the underlying pathology. The purpose of this paper is to present and discuss a clinical algorithm which may be used in the early detection of the underlying causes of impingement symptoms. In this algorithm, a specific chronology and selection of diagnostic tests may offer the clinician a guideline in his physical examination of the athlete with shoulder pain.

Internal impingement in the tennis player: rehabilitation guidelines.

Internal impingement is a commonly described cause of shoulder pain in the overhead athlete, particularly in tennis players. Three shoulder dysfunctions, often correlated with internal impingement symptoms, require attention in the rehabilitation strategy of internal impingement in the tennis player: (1) acquired glenohumeral anterior instability, (2) loss of internal rotation range of motion, and (3) lack of retraction strength. Based on recent literature, the following guidelines are proposed in the rehabilitation of the tennis player with internal impingement symptoms: (1) shoulder rehabilitation should be integrated into kinetic chain training, not only in the advanced phases of the athlete's rehabilitation, but from the initial phases; (2) both angular and translational mobilisations can be used in the treatment of acquired loss of glenohumeral internal rotation range of motion to stretch the posterior structures of the glenohumeral joint; and 3) in the rehabilitation of scapular dyskinesis, the therapist should focus on restoration of intramuscular trapezius muscle balance in the scapular exercises, with special attention to strength training of the retractors.

Trapezius activity and intramuscular balance during isokinetic exercise in overhead athletes with impingement symptoms.

We compared normalized trapezius muscle activity and intramuscular balance ratios between overhead athletes with impingement symptoms and non-injured athletes during isokinetic abduction and external rotation movements. Thirty-nine overhead athletes with chronic impingement symptoms and 30 non-injured athletes participated in the study. Electromyographic activity of upper, middle, and lower trapezius was measured during isokinetic abduction and external rotation, using surface electrodes. The results show a significant increase of upper trapezius activity during both movements in the patient group, with decreased activity in the lower trapezius during abduction, and in the middle trapezius during external rotation. Analysis of the intramuscular activity ratios revealed muscle imbalance on the injured side of the patient group for upper/middle trapezius and upper/lower trapezius during abduction, and for all three muscle activity ratios during external rotation. These results confirm the presence of scapular muscle imbalances in patients with impingement symptoms and emphasize the relevance of restoration of scapular muscle balance in shoulder rehabilitation.

Individual and work related risk factors for neck pain among office workers: a cross sectional study.

Work related neck disorders are common problems in office workers, especially among those who are intensive computer users. It is generally agreed that the etiology of work related neck disorders is multidimensional which is associated with, and influenced by, a complex array of individual, physical and psychosocial factors. The aim of the current study was to estimate the one-year prevalence of neck pain among office workers and to determine which physical, psychological and individual factors are associated with these prevalences. Five hundred and twelve office workers were studied. Information was collected by an online questionnaire. Self-reported neck pain during the preceding 12 months was regarded as a dependent variable, whereas different individual, work-related physical and psychosocial factors were studied as independent variables. The 12 month prevalences of neck pain in office workers was 45.5%. Multivariate analysis revealed that women had an almost two-fold risk compared with men (OR = 1.95, 95% CI 1.22-3.13). The odds ratio for age indicates that persons older than 30 years have 2.61 times more chance of having neck pain than younger individuals (OR = 2.61, 95% CI 1.32-3.47). Being physically active decreases the likelihood of having neck pain (OR = 1.85, 95% CI 1.14-2.99). Significant associations were found between neck pain and often holding the neck in a forward bent posture for a prolonged time (OR = 2.01, 95% CI 1.20-3.38), often sitting for a prolonged time (OR = 2.06, 95% CI 1.17-3.62) and often making the same movements per minute (OR = 1.63, 95% CI 1.02-2.60). Mental tiredness at the end of the workday (OR = 2.05, 95% CI 1.29-3.26) and shortage of personnel (OR = 1.71, 95% CI 1.06-2.76) are significantly associated with neck pain. The results of this study indicate that physical and psychosocial work factors, as well as individual variables, are associated with the frequency of neck pain. These association patterns suggest also opportunities for intervention strategies in order to stimulate an ergonomic work place setting and increase a positive psychosocial work environment.

A home-based multidimensional exercise program reduced physical impairment and fear of falling.

OBJECTIVE: To investigate the efficacy of a guided and graded home-based exercise program for improving a range of physical outcomes in older people. DESIGN: Controlled clinical trial of 16 weeks. SETTING: Two geographical areas in Gent, Belgium. PARTICIPANTS: 66 independent-living older people (age: 71-98) with a history of falls and moderate physical impairment. INTERVENTION: Twenty-four 30-minute training sessions were given by a trained physiotherapist over a period of 16 weeks in the participant's home. Different types of exercises on balance, aerobic performance, flexibility, and muscle strength were provided. MAIN OUTCOME MEASURES: Muscle strength, static and dynamic balance, aerobic performance, activities in daily living, fear of falling and avoidance of daily activities were assessed at baseline and after 16 weeks intervention. RESULTS: At baseline, there were no significant differences in the measured variables between exercise and control groups. After 16 weeks, the exercise group showed significantly improved ankle muscle strength, balance performance and aerobic capacity, and decreased fear of falling, dependency in daily activities and avoidance of daily activities compared to the control group. The improvements in knee muscle strength, timed chair stands, and functional reach were not significant. CONCLUSION: The home-based, individualized exercise program was effective in reducing several physical factors associated with falls in community-dwelling older people with moderate physical impairment. The decrease in fear of falling and other behavioural variables needs to be considered with care and needs further investigation.

Statistical modelling of fatigue-related electromyographic median frequency characteristics of back and hip muscles during a standardized isometric back extension test.

The purpose of the present study was to evaluate which statistical model - linear, logarithmic, quadratic or exponential - best described the fatigue-related electromyographic (EMG) changes of back and hip muscles. Twenty healthy volunteers performed a modified Biering-Sorensen test. The EMG activity of the latissimus dorsi (LD), longissimus thoracis pars thoracis (LTT) and lumborum (LTL), iliocostalis lumborum pars thoracis (ILT) and lumborum (ILL), multifidus (MF), gluteus maximus (GM) and biceps femoris (BF) was measured bilaterally using surface electrodes. Higher R(2) values were found for the quadratic models (p<0.05 for all muscles), and lower R(2) values for the logarithmic models (p<0.05 for LTT, LTL, ILL, MF and GM). The exponential models generated higher R(2) values compared to the linear ones for the LTT, LTL and MF (all p<0.05). Further analyses revealed, however, that these models did not add useful additional information, and therefore would only increase the complexity. The findings of the current study validate the use of simple linear regression techniques when studying fatigue-related EMG median frequency characteristics of back and hip muscles during isometric contractions.

Effect of bracing on the prevention of anterior knee pain--a prospective randomized study.

There have been numerous reports about the use of knee braces to prevent traumatic knee injuries. Despite the frequent use of braces, very few prospective studies have been performed to study the effect of knee braces for preventing anterior knee pain syndrome (AKPS). The purpose of this study was to assess the effectiveness of a dynamic patellofemoral brace (On-Track System, dj Orthopedics) in the prevention of AKPS. 167 military recruits without history of knee pain were randomized into two groups prior to the start of their 6-week basic military training (BMT) program. The first group (brace group) consisted of 54 recruits who wore the braces for all physical activities during these 6 weeks. 113 recruits served as a control group, and followed the same 6-week strenuous training program. Chi square statistics (Fisher exact test) were used to compare the number of AKPS patients in the brace group and in the non-brace group. Our results indicated that recruits in the brace group appeared to develop significantly less anterior knee pain compared to the recruits in the control group (p=0.020). Out of the 54 recruits in the brace group, ten (18.5%) developed anterior knee pain during this study. In the control group (n=113), 42 recruits (37%) developed anterior knee pain. We conclude that the result of the present study suggests that the use of a dynamic patellofemoral brace is an effective way to prevent the development of anterior knee pain in persons undergoing a strenuous training program.

Evaluation of isokinetic force production and associated muscle activity in the scapular rotators during a protraction-retraction movement in overhead athletes with impingement symptoms.

OBJECTIVES: To determine if the muscle force and electromyographic activity in the scapular rotators of overhead athletes with impingement symptoms showed differences between the injured and non-injured sides. METHODS: Isokinetic peak force was evaluated during protraction and retraction of the shoulder girdle, with simultaneous recording of electromyographic activity of the three trapezius muscles and the serratus anterior muscle, in 19 overhead athletes with impingement symptoms. RESULTS: Paired t tests showed significantly lower peak force during isokinetic protraction at high velocity (p<0.05), a significantly lower protraction/retraction ratio (p<0.01), and significantly lower electromyographic activity in the lower trapezius muscle during isokinetic retraction on the injured side than on the non-injured side (p<0.05). CONCLUSION: These results confirm that patients with impingement symptoms show abnormal muscle performance at the scapulothoracic joint.

The effect of exercise regimens on reflex response time of the vasti muscles in patients with anterior knee pain: a prospective randomized intervention study.

The purpose of this prospective randomized intervention study was to evaluate the effect of two exercise protocols on reflex response time of vastus medialis obliquus (VMO), vastus lateralis (VL), in patients with anterior knee pain. Sixty patients were randomized into a 5-week treatment program, which consisted of only open kinetic chain tonification exercises (group I) (n = 30), or only closed kinetic chain tonification exercises (group II) (n = 30). Assessment of an aspect of neuromotor control was obtained by measuring the reflex response times of VMO and VL at the time of initial clinical examination, at the end of the exercise period (five weeks), and three months after the completion of the exercise period. At these evaluation occasions, the intensity and the number of times that the patients experienced anterior knee pain during daily life was recorded on a Visual Analog Scale (VAS). No alterations in reflex response times of VMO and VL were observed in either group. Changes of anterior knee pain over time were statistically significant in both groups. Only small and not statistically supported differences in anterior knee pain were found between the two groups. These results suggest that the reflex response times of the two vasti muscles can not be altered after a five week open or closed kinetic chain exercise program. In contrast, knee pain decreased significantly in both groups.

Treating sensory impairments in the post-stroke upper limb with intermittent pneumatic compression. Results of a preliminary trial.

OBJECTIVE: To evaluate the efficacy of intermittent pneumatic compression (IPC) in treating sensory impairments in the hemiplegic upper limb in stroke patients. DESIGN: Twenty-three stroke patients were enrolled in a randomized, controlled preliminary trial that compared the application of intermittent pneumatic compression with a passive treatment strategy. SETTING: Four Belgian day centres for treatment of neurological disabilities. Four acute and rehabilitation care wards specialized in neurological treatment. SUBJECTS: Twenty-three stroke patients. INTERVENTIONS: The experimental group (n = 11) received standard physiotherapy combined with intermittent pneumatic compression treatment (10 cycles of 3 minutes with a peak of 40 mmHg) for their hemiplegic upper limb. The control group (n = 12) received supplementary to their conventional physiotherapy a placebo treatment, namely sham short-wave therapy on the hemiplegic shoulder for 30 minutes. MAIN OUTCOME MEASURES: Sensory impairments were clinically assessed at three occasions over a period of four weeks using the Nottingham Sensory Assessment scale. RESULTS: Both groups improved in somatosensation over time, but the experimental group improved more than the control group (p= 0.036) or 81.1% improvement versus 30.9%. CONCLUSIONS: The use of intermittent pneumatic compression in the rehabilitation of stroke patients may be of clinical importance for the restoration of sensory function.