Gait pattern in two rare genetic conditions characterized by muscular hypotonia: Ehlers-Danlos and Prader-Willi syndrome

This study aimed to quantify and compare the gait pattern in Ehlers-Danlos (EDS) and Prader-Willi syndrome (PWS) patients to provide data for developing evidence-based rehabilitation strategies. Twenty EDS and 19 PWS adult patients were evaluated with an optoelectronic system and force platforms for measuring kinematic and kinetic parameters during walking. The results were compared with those obtained in a group of 20 normal-weight controls (CG). The results showed that PWS patients walked with longer stance duration and reduced velocity than EDS, close to CG. Both EDS and PWS showed reduced anterior step length than CG. EDS kinematics evidenced a physiological position at proximal joints (pelvis and hip joint) while some deficits were displayed at knee (reduced flexion in swing phase) and ankle level (plantar flexed position in stance and reduced dorsal flexion in swing). PWS showed a forward tilted pelvis in the sagittal plane, excessive hip flexion during the whole gait cycle and an increased hip movement in the frontal plane. Their knees were flexed at initial contact with reduced range of motion while ankle joints showed a plantar flexed position during stance. No differences were found in terms of ankle kinetics and joint stiffness. Our data showed that EDS and PWS patients were characterized by a different gait strategy: PWS showed functional limitations at every level of the lower limb joints, whereas in EDS limitations, greater than PWS, were reported mainly at the distal joints. PWS patients should be encouraged to walk for its positive impact on muscle mass and strength and energy balance. For EDS patients the rehabilitation program should be focused on ankle strategy improvement.

The effect of vision on postural strategies in Prader-Willi patients

The aim of this study was to quantify the role of visual contribution in patients with Prader-Willi syndrome (PWS) on balance maintenance using a force platform. We enrolled 14 individuals with PWS free from conditions associated with impaired balance, 44 obese (OG) and 20 healthy controls (CG). Postural sway was measured for 60s while standing on a force platform (Kistler, CH; acquisition frequency: 500 Hz) integrated with a video system. Patients maintained an upright standing position with Open Eyes (OE) and then with Closed Eyes (CE). The ratio between the value of the parameter under OE and CE conditions was measured. Under OE condition PWS and OG were characterized by higher postural instability than CG, with the PWS group showing poorer balance capacity than OG. The Romberg ratio showed that while OG and CG had lower balance without vision, PWS maintained the same performance changing from OE to CE. The integration of different sensory inputs appears similar in OG and CG with higher postural stability under OE than CE. Balance in PWS is not influenced by the elimination of visual input.

Fractal dimension approach in postural control of subjects with Prader-Willi Syndrome

BACKGROUND

Static posturography is user-friendly technique suitable for the study of the centre of pressure (CoP) trajectory. However, the utility of static posturography in clinical practice is somehow limited and there is a need for reliable approaches to extract physiologically meaningful information from stabilograms. The aim of this study was to quantify the postural strategy of Prader-Willi patients with the fractal dimension technique in addition to the CoP trajectory analysis in time and frequency domain.

METHODS

11 adult patients affected by Prader-Willi Syndrome (PWS) and 20 age-matched individuals (

CONTROL GROUP

CG) were included in this study. Postural acquisitions were conducted by means of a force platform and the participants were required to stand barefoot on the platform with eyes open and heels at standardized distance and position for 30 seconds. Platform data were analysed in time and frequency domain. Fractal Dimension (FD) was also computed.

RESULTS

The analysis of CoP vs. time showed that in PWS participants all the parameters were statistically different from CG, with greater displacements along both the antero-posterior and medio-lateral direction and longer CoP tracks. As for frequency analysis, our data showed no significant differences between PWS and CG. FD evidenced that PWS individuals were characterized by greater value in comparison with CG.

CONCLUSIONS

Our data showed that while the analysis in the frequency domain did not seem to explain the postural deficit in PWS, the FD method appears to provide a more informative description of it and to complement and integrate the time domain analysis.

[Impact of obesity-related disability in different work categories]

Absenteeism and sick leave are often reported in obese workers. To evaluate disability work related we assess 180 overweight-obese subjects [BMI 34,6 + 6,4, range 26,0-59,0) with TSD-OC questionnaire divided into 7 items (pain; stiffness; ADL; housework; IADL; occupational activities; social life) with a total of 36 visual analogue scales. Among the job categories, health-care workers showed the highest TSD-OC total score (26,9 + 22,5%, ANOVA p < 0,05) and BMI (BMI 37,7 + 6,9 kg/m2). Among the items, pain was statistically significant in health-care workers (16,1 + 13,2%), in Services (16,3 + 14,3%), in Education (15,1 + 11,4%) and in Administration (13,3 +11,0%) ( p <0,05). "Occupational activities" item was statistically significant in health-care (11, 6 +10,6%, p <0,05).

Postural adaptations to long-term training in Prader-Willi patients

Background

Improving balance and reducing risk of falls is a relevant issue in Prader-Willi Syndrome (PWS). The present study aims to quantify the effect of a mixed training program on balance in patients with PWS.

Methods

Eleven adult PWS patients (mean age: 33.8 ± 4.3 years; mean BMI: 43.3 ± 5.9 Kg/m2) attended a 2-week training program including balance exercises during their hospital stay. At discharge, Group 1 (6 patients) continued the same exercises at home for 6 months, while Group 2 (5 patients) quitted the program. In both groups, a low-calorie, well-balanced diet of 1.200 kcal/day was advised. They were assessed at admission (PRE), after 2 weeks (POST1) and at 6-month (POST2). The assessment consisted of a clinical examination, video recording and 60-second postural evaluation on a force platform. Range of center of pressure (CoP) displacement in the antero-posterior direction (RANGE_AP index) and the medio-lateral direction (RANGE_ML index) and its total trajectory length were computed.

Results

At POST1, no significant changes in all of the postural parameters were observed. At completion of the home program (POST2), the postural assessment did not reveal significant modifications. No changes in BMI were observed in PWS at POST2.

Conclusions

Our results showed that a long-term mixed, but predominantly home-based training on PWS individuals was not effective in improving balance capacity. Possible causes of the lack of effectiveness of our intervention include lack of training specificity, an inadequate dose of exercise, an underestimation of the neural and sensory component in planning rehabilitation exercise and failed body weight reduction during the training. Also, the physiology of balance instability in these patients may possibly compose a complex puzzle not affected by our exercise training, mainly targeting muscle weakness.

Assessing disability in morbidly obese individuals: the Italian Society of Obesity test for obesity-related disabilities

PURPOSE

To validate a new obesity-specific disability assessment test: the Obesity-related Disability test (Test SIO Disabilità Obesità Correlata, TSD-OC).

METHODS

Adult obese individuals were assessed with the TSD-OC, 36-Item Short-Form Health Survey (SF-36), 6-min walking test (6MWT) and grip strength. The TSD-OC is composed of 36 items divided into seven sections (pain, stiffness, activities of daily living and indoor mobility, housework, outdoor activities, occupational activities and social life). Statistical correlations between the TSD-OC, functional assessment (6MWT and grip strength) and quality of life parameters (SF-36) were analysed. Internal consistency was assessed with Cronbach's α test. Test-retest reliability was evaluated in a subgroup of 30 individuals. A linking exercise between TSD-OC items and categories of the International Classification of Functioning, Disability and Health was performed.

RESULTS

Test-retest showed excellent stability (r = 0.90) and excellent internal consistency was reported (Cronbach's α > 0.90). Significant low to moderate correlations between TSD-OC, SF-36 scores, 6MWT and grip strength were observed. A total of 26 ICF categories were linked, mostly related to the area of mobility.

CONCLUSIONS

The TSD-OC is a reliable and valid instrument for measuring self-reported disability in obese subjects. It may represent an important tool for establishing rehabilitation needs in individuals with obesity-related disability, for planning appropriate rehabilitation programmes and for evaluating their effectiveness.

The effects of muscle hypotonia and weakness on balance: a study on Prader-Willi and Ehlers-Danlos syndrome patients

Prader-Willi syndrome (PWS) and Ehlers-Danlos syndrome (EDS) are two different genetical disorders both characterized, among other features, by muscular hypotonia. Postural control seems to be impaired in both conditions. The aim of the present study was to quantitatively compare postural control in adult PWS and EDS using stabilometric platform to unveil possible common determinants of impaired balance. We enrolled 11 PWS and 21 EDS adult patients and 20 age-matched controls. They were instructed to maintain an upright standing position for 30s with open eyes (OEs) focusing on a 6 cm black circle positioned at a distance of 1.5m. Both PWS and EDS patients were characterized by higher RANGEML, RANGEAP and trajectory length of CoP values as compared to CG. No statistically differences were found between PWS and EDS in terms of any of these parameters. The results demonstrated that both PWS and EDS are characterized by a severe postural instability. Muscle hypotonia and weakness may account for reduced balance capacity. Quantitative characterization of instability is important to identify, develop and enhance rehabilitation interventions.

Mechanisms underlying center of pressure displacements in obese subjects during quiet stance

Objective

the aim of this study was to assess whether reduced balance capacity in obese subjects is secondary to altered sensory information.

Design

cross sectional study.

Subjects

44 obese (BMI = 40.6 ± 4.6 kg/m² , age = 34.2 ± 10.8 years, body weight: 114,0 ± 16,0 Kg, body height 167,5 ± 9,8 cm) and 20 healthy controls (10 females, 10 males, BMI: 21.6 ± 2.2 kg/m², age: 30.5 ± 5.5 years, body weight: 62,9 ± 9,3 Kg, body height 170,1 ± 5,8 cm) were enrolled.

Measurements

center of pressure (CoP) displacements were evaluated during quiet stance on a force platform with eyes open (EO) and closed (EC). The Romberg quotient (EC/EO) was computed and compared between groups.

Results

we found statistically significant differences between obese and controls in CoP displacements (p < 0.01) and no statistically significant differences in Romberg quotients (p > 0.08).

Conclusion

the increased CoP displacements in obese subjects do not need an hypothesis about altered sensory information. The integration of different sensory inputs appears similar in controls and obese. In the latter, the increased mass, ankle torque and muscle activity may probably account for the higher CoP displacements.

Postural strategies in Prader-Willi and Down syndrome patients

Patients affected by Down (DS) and Prader-Willi syndrome (PWS) are characterised by some common clinical and functional features including gait disorders and reduced postural control. The aim of our study was to quantitatively compare postural control in adult PWS and DS. We studied 12 PWS and 19 DS adult patients matched for age, height, weight and body mass index. They were instructed to maintain an upright standing position on a force platform for 30s with open eyes (OE) and we calculated the range of center of pressure (CoP) displacement in the A/P direction (RANGE(AP)) and in the M/L direction (RANGE(ML)) and the total CoP trajectory length during quiet stance (Sway Path, SP). The range of oscillations in PWS and DS in both AP and ML direction were higher than in controls. PWS and DS were statistically different for RANGE(AP), with PWS showing higher mean values. Our results confirm a reduced capacity of both PWS and DS in maintaining postural stability. This appears to be in some respect different in PWS and DS, with PWS showing poorer control in AP. DS and, particularly, PWS should be encouraged to undergo specific balance training and strengthening of the ankle muscles as part of a comprehensive rehabilitation program to enhance daily functioning and quality of life.

Functional limitations and occupational issues in obesity: a review

Four hundred million adults are obese. Such a pandemic involves people of working age. Excess weight imposes abnormal mechanics on body movements, which could account for the high incidence of musculoskeletal disorders in these subjects. This article reviews the physiological and biomechanical causes of the reduced work capacity in obese workers and speculates on the relationships between occupational exposure and obesity. The reduction in work capacity appears to be due to the following factors: reduced spine flexibility, decay in endurance, limited range of movement of the major joints, reduced muscle strength and capacity to hold prolonged fixed postures, impaired respiratory capacity and visual control. Work capacity in morbidly obese workers should always be evaluated to match specific job demands. Due to the relationship between obesity, musculoskeletal disorders, disability and health costs, prevention of obesity and ergonomic interventions on-site are a priority in the work place.

Characterisation of balance capacity in Prader-Willi patients

Being severely overweight is a distinctive clinical feature of Prader-Willi Syndrome (PWS). This explorative study aims to characterise balance capacity in PWS as compared to non-genetically obese patients (O) and to a group of normal-weight individuals (CG). We enrolled 14 PWS patients: 8 females and 6 males (BMI = 41.3 ± 7.3 kg/m(2), age = 32.86+4.42 years), 44 obese individuals, 22 males and 22 females (BMI = 40.6 ± 4.6 kg/m(2), age = 34.2 ± 10.7 years) and 20 controls (CG: 10 females and 10 males; BMI: 21.6 ± 1.6 kg/m(2); age: 30.5 ± 5.3 years). Postural acquisitions were conducted by means of a force platform from which the COP pattern vs time was analysed. The participants were required to stand barefoot on the platform with eyes open and heels at standardized distance and position for 60s. All of the analysed parameters were statistically different from O and CG groups. PWS individuals showed greater displacements in both the A/P and M/L direction (RMS, RANGE and MV indices). Analysis of the overall planar movement of the CoP showed that the PWS patients were characterised by higher RMS distance from the centre (RMS(CoP) index) and area of confidence ellipse (AREA(CoP) index) when compared both to obese and healthy individuals. PWS patients showed a poorer balance capacity than their non-genetically obese counterparts and healthy individuals, with greater differences in both the A/P and M/L direction than O. Rehabilitation programs for PWS should take this finding into account. In addition to weight loss, strengthening of ankle flexors/extensors, and balance training, tailored interventions aimed at improving A/P control should be given particular consideration.

[Obesity and work: an emerging problem]

In Italy, 42.5% of adult males is overweight and 10.5% obese, while 26.6% of the women is overweight and 9.1% obese. The economical consequences of a growing number of obese workers are relevant: obesity is associated to reduced participation to productive life, increased absenteeism, disability and need for health care, lower salaries, negative impact on productivity. The obese worker is characterized by reduced tolerance to effort, limited range of motion at spinal and joints level, reduced muscle strength normalized per body weight, lower tolerance to prolonged postures, reduced balance and overall reduced work capacity linear to the increase of body mass index. The present article reviews the most evident relationships between work factors (stress, musculoskeletal disorders, etc.) and obesity and speculates about possible interventions to prevent occupational issues for obese workers.

Effectiveness of a 6-month home-based training program in Prader-Willi patients

In addition to hypotonia and relative sarcopenia, patients with Prader-Willi syndrome (PWS) show reduced spontaneous physical activity and gait disorders. Scant evidence exists that daily muscle training increases their lean mass and physical activity levels. Whether adequate long-term physical training is feasible and effective in improving muscle function and gait in PWS is still unknown. Eleven adult PWS patients (mean age: 33.8±4.3 years; mean BMI: 43.3±5.9 kg/m(2)) admitted to our hospital were enrolled in this study. During their hospital stay they attended a 2-week rehabilitation program which included supervised exercise sessions. At discharge, Group 1 (6 patients) continued the same exercises at home for 6 months, while Group 2 (5 patients) did not continue home-based training. They were assessed at admission (PRE), at 2 weeks (POST1) and at 6 months (POST2). The assessment consisted of a clinical examination, 3D gait analysis and muscle strength measurement with an isokinetic dynamometer. After 2 weeks of supervised training (POST1), no significant changes in spatial-temporal gait parameters were observed, although significant improvements in ankle dorsal flexion during stance and swing and knee flexor strength were evidenced by 3D gait analysis and dynamometry in all patients. Following 6 months of home training (POST2), Group 1 had showed significant improvements in cadence and reduced knee hyperextension in mid-stance. Ankle plantar and dorsal flexors isokinetic strength had improved significantly at 120° s(-1), whereas Group 2 showed no changes in their spatial-temporal and kinematic parameters. The present study reinforces the idea that even in participants with PWS who present with a distinctive psychological profile, long-term group interventions are feasible and effective in improving their overall physical functioning. Providing an effective and simple home-based training program represents a continuum of the rehabilitation process outside the hospital, which is a crucial issue in chronic conditions.

Gait patterns in Prader-Willi and Down syndrome patients

Background

Prader-Willi (PWS) and Down Syndrome (DS) are two genetic disorders characterised by some common clinical and functional features. A quantitative description and comparison of their patterns would contribute to a deeper understanding of the determinants of motor disability in these two syndromes. The aim of this study was to measure gait pattern in PWS and DS in order to provide data for developing evidence-based deficit-specific or common rehabilitation strategies.

Methods

19 PWS patients (17.7-40 yr) and 21 DS patients (18-39 yr) were evaluated with an optoelectronic system and force platforms for measuring kinematic and kinetic parameters during walking. The results were compared with those obtained in a group of normal-weight controls (Control Group: CG; 33.4 + 9.6 yr).

Results and Discussion

The results show that PWS and DS are characterised by different gait strategies. Spatio-temporal parameters indicated a cautious, abnormal gait in both groups, but DS walked with a less stable strategy than PWS. As for kinematics, DS showed a significantly reduced hip and knee flexion, especially at initial contact and ankle range of motion than PWS. DS were characterised by lower ranges of motion (p < 0.05) in all joints than CG and PWS. As for ankle kinetics, both PWS and DS showed a significantly lower push-off during terminal stance than CG, with DS yielding the lowest values. Stiffness at hip and ankle level was increased in DS. PWS showed hip stiffness values close to normal. At ankle level, stiffness was significantly decreased in both groups.

Conclusions

Our data show that DS walk with a less physiological gait pattern than PWS. Based on our results, PWS and DS patients need targeted rehabilitation and exercise prescription. Common to both groups is the aim to improve hypotonia, muscle strength and motor control during gait. In DS, improving pelvis and hip range of motion should represent a major specific goal to optimize gait pattern.

Gender-specific effect of obesity on balance

Obesity modifies the body geometry by adding mass to different regions and it influences the biomechanics of activities of daily living. Weight influences postural stability, but there is no consensus as to whether the different fat distribution in males and females produces gender-related effects on balance. The aim of this study was to investigate the effect of body weight increases on postural performance in males and females. A total of 22 obese females (BMI: 41.1+/-4.1 kg/m2) and 22 obese males (BMI: 40.2+/-5 kg/m2) were analyzed during a static posture trial on a force platform in standardized conditions. Twenty healthy subjects (10 females, 10 males) constituted the control group. We computed the following parameters related to the center of pressure (CoP): velocity and displacements along the antero-posterior (AP) and medio-lateral axis (ML). We found several statistically significant differences between healthy and obese men, in particular regarding the AP and ML CoP parameters, which were correlated to body weight (r=0.36-0.58). The comparison between healthy and obese females pointed out statistically significant differences in AP parameters and no significant differences in ML displacements. Body weight was found to correlate with AP parameters (r=0.36-0.74), but not with ML displacements. The increased body mass seems to produce AP instability in both genders and ML destabilization only in males. Rehabilitation programs should take these findings into account by adopting specific interventions to improve ML control in obese males, and through weight loss and strengthening of ankle flexors/extensors in both genders.

Balance in patients with anorexia and bulimia nervosa

AIM

Neuro-muscular adaptations to the loss or increase in body weight may induce postural alterations. The aim of this study was to investigate the effect of body weight alterations on postural stability in patients with anorexia nervosa and bulimia.

METHODS

The study enrolled 15 women affected by anorexia nervosa (AN), (mean body mass index [BMI] 15.8+/-1.8 kg/m(2)), 15 women affected by bulimia nervosa (BN), (mean BMI 20.1+/-2.9 kg/m(2)) and 11 healthy matched women (HC), (mean BMI 20.1+/-1 kg/m(2)). Two quiet standing conditions with eyes open (EO) and closed (EC) were analysed with an optoelectronic system (Vicon 460, Viconpeak, Oxford, UK) with passive markers to estimate the centre of mass (CoM) position.

RESULTS

BN patients were more unstable than HC, showing statistically significant differences in antero-posterior CoM excursions and path length. AN patients showed non significant differences from HC. Only HC showed differences between EO and EC conditions, with significantly greater excursions in medio-lateral direction in EC condition (P<0.013) as well as an increased sway area (P<0.022).

CONCLUSIONS

In BN, musculoskeletal factors seem to play a major role in the diminished postural control, which appear to be linked to body weight fluctuations rather than to BMI absolute values. No clear-cut postural instability was demonstrated in patients with AN as compared to HC. Visual input appears not to affect balance in patients with eating disorders. Possible further causes of postural instability in BN and implications for rehabilitation treatment are discussed.

Mechanical external work and recovery at preferred walking speed in obese subjects

PURPOSE

The aim of this study was to compare the mechanical external work (per kg) and pendular energy transduction at preferred walking speed (PWS) in obese versus normal body mass subjects to investigate whether obese adults adopt energy conserving gait mechanics.

METHODS

The mechanical external work (Wext) and the fraction of mechanical energy recovered by the pendular mechanism (Rstep) were computed using kinematic data acquired by an optoelectronic system and were compared in 30 obese (OG; body mass index [BMI] = 39.6 +/- 0.6 kg m(-2); 29.5 +/- 1.3 yr) and 19 normal body mass adults (NG; BMI = 21.4 +/- 0.5 kg m(-2); 31.2 +/- 1.2 yr) walking at PWS.

RESULTS

PWS was significantly lower in OG (1.18 +/- 0.02 m s(-1)) than in NG (1.33 +/- 0.02 m s(-1); P <or= 0.001). There was no significant difference in Wext per unit mass between groups (OG: 0.36 +/- 0.03 J kg(-1) m(-1); NG: 0.31 +/- 0.02 J kg(-1) m(-1); P = 0.12). Rstep was significantly lower in OG (68.4% +/- 2.0%) compared with NG (74.4% +/- 1.0%; P = 0.01). In OG only, Wext per unit mass was positively correlated with PWS (r = 0.57; P < 0.001).

CONCLUSION

Obese adults do not appear to alter their gait to improve pendular energy transduction and may select slower PWS to reduce mechanical and metabolic work.

Strength characterization of knee flexor and extensor muscles in Prader-Willi and obese patients

Background

despite evidence of an obesity-related disability, there is a lack of objective muscle functional data in overweight subjects. Only few studies provide instrumental strength measurements in non-syndromal obesity, whereas no data about Prader-Willi syndrome (PWS) are reported. The aim of our study was to characterize the lower limb muscle function of patients affected by PWS as compared to non-syndromal obesity and normal-weight subjects.

Methods

We enrolled 20 obese (O) females (age: 29.1 ± 6.5 years; BMI: 38.1 ± 3.1), 6 PWS females (age: 27.2 ± 4.9 years; BMI: 45.8 ± 4.4) and 14 healthy normal-weight (H) females (age: 30.1 ± 4.7 years; BMI: 21 ± 1.6). Isokinetic strength during knee flexion and extension in both lower limbs at the fixed angular velocities of 60°/s, 180°/s, 240°/s was measured with a Cybex Norm dynamometer.

Results

the H, O and PWS populations appear to be clearly stratified with regard to muscle strength.: PWS showed the lowest absolute peak torque (PT) for knee flexor and extensor muscles as compared to O (-55%) and H (-47%) (P = 0.00001). O showed significantly higher strength values than H as regard to knee extension only (P = 0.0014). When strength data were normalised by body weight, PWS showed a 50% and a 70% reduction in PT as compared to O and H, respectively. Knee flexors strength values were on average half of those reported for extension in all of the three populations.

Conclusion

the novel aspect of our study is the determination of objective measures of muscle strength in PWS and the comparison with O and H patients. The objective characterization of muscle function performed in this study provides baseline and outcome measures that may quantify specific strength deficits amendable with tailored rehabilitation programs and monitor effectiveness of treatments.

[Risk reduction in handling obese patients]

BACKGROUND

Hospital staff are exposed to significant risk in the manual handling and care of obese patients.

OBJECTIVES

to illustrate how risk reduction can be achieved by means of integrated measures, particularly aimed at developing specific know-how among the operators, and the use of safety guidelines and technical aids for transferring obese patients in various situations.

METHODS

on the basis of the recent literature, the present article reviews the technological aids and the preventive procedures that ensure safe transfer and health care of obese patients.

RESULTS

Many devices are available in the USA for the handling and assisting the obese patient; however, much remains to be done for the development of specific equipment. In Italy, along with knowledge of the devices, specific competence needs to be promoted among the operators dealing with obese patients. Organizational and structural issues arise from this new specialty.

CONCLUSIONS

An integrated approach, requiring suitable environments, ergonomic devices, standard procedures and personnel competence needs to be adopted in order to reduce the risk in health-care workers dealing with obese patient.

Resistance training of long duration modulates force and unloaded shortening velocity of single muscle fibres of young women

The aim of the present study was to clarify the impact of long term (1 year) resistance training (RT) on structure and function of single muscle fibres of vastus lateralis in young female subjects. Five young women (age: 25.4+/-6.2 year) performed exercise sessions at 60% of single subject own repetition maximum (1 RM) 1h twice a week. Maximum voluntary force was determined pre- and post-RT and was found to significantly increase post-RT ensuring a successful impact of RT on muscle performance in vivo. Needle muscle biopsy samples were obtained both pre- and post-RT and the following determinations were performed: myosin heavy chain isoform (MHC) distribution of the whole muscle samples by SDS-PAGE; cross sectional area (CSA), specific force (Po/CSA) and maximum shortening velocity (Vo) of a large population (n=358) of single skinned muscle fibres classified on the basis of MHC isoform composition by SDS-PAGE. The results suggest that the long duration of RT can determine a significant increase in specific force (Po/CSA) and unloaded shortening velocity (Vo) of single muscle fibres in female subjects, whereas no muscle fibre hypertrophy and no shift in MHC isoform content was observed.

Kinematics of trunk movements: protocol design and application in obese females

PURPOSE

Whether kinematic analysis of the trunk can provide useful clinical insight into the relationship between function and various spinal conditions is still under debate. The aim of this study was to develop a clinical protocol and an associated biomechanical model to characterize quantitatively the trunk movements in obese subjects.

METHODS

Twenty (10 obese, 10 control) female subjects were evaluated with an optoelectronic system and passive markers attached to the spine during forward flexion, lateral bending, and rotation of the trunk.

RESULTS

We found a systematic error due to skin artifacts of less than 5 degrees in both groups. Intra- and inter-subject standard deviation was less than 6 degrees . Obese subjects demonstrated a significantly reduced motion in the thoracic spine associated with an increased pelvic tilt angle as compared to controls.

CONCLUSIONS

Our protocol was able to characterize trunk mobility in obese and normal subjects suggesting that kinematics could represent, even in an obese population, a promising method to investigate subclinical spinal disorders and to assess the effectiveness of rehabilitation programs.

[Treadmills in rehabilitation medicine: technical characteristics and selection criteria]

The treadmill is a commonly used means of testing and training patients with cardiopulmonary diseases. There is growing interest in the use of the treadmill also for rehabilitation of patients with orthopaedic and neurological diseases. Commercially available treadmills show wide differences in terms of structure and function that have a direct impact on the specific rehabilitation protocols. The aims of this paper are: a) to briefly review the physiology and biomechanics of treadmill exercise as compared to overground walking; b) to point out the technical specifications of treadmills suitable for rehabilitation settings; c) to provide guidelines for treadmill selection in the different categories of rehabilitation patients. First, the different physiological and biomechanical characteristics of walking on a treadmill and overground are discussed. Uphill and downhill walking as well as backward walking are also presented together with the spin-offs for rehabilitation practice. Then, the technical features of treadmills (treadbelt, frame, bars, deck, rollers, shock absorption, elevation motor, drive motor, flywheel, display) are described and the specific requisites for the different patient categories undergoing rehabilitation are discussed in detail. Finally, guidelines and a flow-chart for identifying the main technical requisites for appropriate treadmill selection in the different disabilities are provided. A summary table of the technical specifications of the commercially available rehabilitation treadmills is also included.

[Cycle ergometers in rehabilitation medicine: technical characteristics and selection criteria]

The cycle ergometer is a commonly used means of testing and training patients with energetic disabilities (particularly in the area of cardiopulmonary diseases). Recent evidence suggests that cycle ergometers can also be useful in patients with subacute and chronic stroke, brain injury, chronic degenerative neurological conditions, and in spinal cord injury. Commercially available cycle ergometers show wide differences in terms of structure and function that have a direct impact on the specific rehabilitation protocols. The aims of this review paper are: a) to briefly review the physiology and biomechanics of exercise on a cycle ergometer; b) to review and discuss the technical specifications of the cycle ergometers suited to rehabilitation settings; c) to provide guidelines for selecting appropriate cycle ergometers for the different categories of rehabilitation patients. First, the physiology of exercise on the cycle ergometer and its biomechanical features are discussed, including the patterns of muscular activity during down- and up-stroke. Upright and recumbent ergometers and their specific clinical indications are compared. Finally, the technical characteristics of the cycle ergometers (load, motor, resistance, flywheel, belt, resilience, pedals, frame, display) are described and the specific requisites for the different patient categories undergoing rehabilitation are discussed in detail. Finally, guidelines are offered for identifying the main technical requisites for appropriate cycle ergometer selection in the different disabilities.