Posturographic analysis of balance control in patients with haemophilic arthropathy

Stability, Balance, and Physical Variables in Patients with Bilateral Hemophilic Arthropathy of the Ankle versus Their Healthy Peers: A Case-Control Study

(1) Background: The recurrence of hemarthrosis in patients with hemophilia triggers a pathophysiological process of degenerative, progressive, and irreversible joint destruction. This hemophilic arthropathy is characterized by chronic pain, muscle atrophy, loss of mobility, and proprioceptive alterations. As the same joint undergoes repeated hemarthrosis, the function of the mechanical receptors deteriorates, causing a pathophysiological modulation and deterioration of the musculoskeletal system. The objective was to analyze the differences in stability and balance, as well as in ankle dorsal flexion, functionality, and muscle strength, between patients with bilateral hemophilic arthropathy and their healthy peers. (2) Methods: A cross-sectional descriptive case-control study was performed. Twenty-two participants were recruited: 10 adult patients with bilateral hemophilic arthropathy of the knee and ankle and 12 healthy subjects. The variables were balance (Rs Scan pressure platform), ankle dorsiflexion range of motion (Leg Motion), functionality (2-Minute Walk Test), and ankle dorsal strength (dynamometry). (3) Results: Statistically significant differences (p < 0.05) were found in the balance without visual support in the Max-Y variable (MD = 2.83; CI95%: 0.33;5.33; Effect size (d) = 0.67), ankle dorsiflexion (MD = 16.00; CI95%: 14.30; 20.0; d = 7.46), and strength of the ankle flexor muscles (MD = 128.50; CI95%: 92.50; 153.60; d = 2.76). (4) Conclusions: Ankle range of motion in dorsal flexion, functionality, and muscle strength in dorsal flexion is poorer in patients with bilateral lower limb hemophilic arthropathy than in their healthy peers. Patients with bilateral hemophilic ankle arthropathy have statistically poorer stability and balance without visual support than their healthy peers.

Past the tipping point: a qualitative study of the views and experiences of men with haemophilia regarding mobility, balance, and falls

PURPOSE

The life expectancy of people with haemophilia is increasing due to improved medical care. This improvement is accompanied by the co-morbidities of ageing, which include musculoskeletal degeneration and the associated effect on proprioception and balance. This study aims to explore the views and everyday experiences of those living with haemophilia regarding this.

MATERIALS AND METHODS

Nine people with moderate or severe haemophilia aged 43-58 years participated in semi-structured interviews and thematic analysis was used to examine the data.

RESULTS

Participants described pain and reduced movement in joints as a result of repeated bleeds, which caused problems with mobility and balance. Constant vigilance of their surroundings together with the potential consequences of bleeds caused continual worry. Participants were resourceful in their strategies to cope with the effects of haemophilia, to reduce pain and to minimise the risk of falling. However, participants felt stigmatised because of their condition.

CONCLUSION

People with haemophilia have difficulties with their mobility and balance that can increase their risk of falling. Healthcare professionals need to understand and address the physical and psycho-social factors that contribute to the risk of falls. A multi-disciplinary approach to devise effective strategies to counteract and monitor the risk of falls would be useful.Implications for RehabilitationHealthcare professionals should identify movements that are fearful and work on ways to increase confidence and ability to perform these.Healthcare professionals need to identify the recovery strategies used to maintain balance and build these movements into home exercise programmes.Effective pain reduction strategies, both pharmacological and non-pharmacological, need to be investigated and optimised.Footwear choice has implications for both pain reduction and balance and should be discussed in routine reviews.Optimising vision would maximise visual input to aid balance.

Postural Assessment Systems in the Prevention of Haemophilic Arthropathy: A Narrative Review

This narrative review aims to give an overview of some postural evaluation systems currently used in patients with haemophilia. Among them, first, we analyse the HJHS scale, recognized as a specific evaluation tool for haemophilic arthropathy. Second, we focus on other systems usually used in non-haemophilic patients that have also shown good applicability in this patient category, such as gait analysis, stabilometry, and baropodometric examination. This review underlines the use these tools could have in clinical practice to identify the early postural alterations in patients with haemophilia and set up personalised rehabilitation programs.

The effects of close kinetic chain exercises on proprioception and physical activity level in pediatric patients with hemophilia

INTRODUCTION

Knee joint proprioception is affected, and lower extremity functioning declines over time in patients with hemophilia A.

AIM

To investigate the effects of a structured exercise programme consisting of the close kinetic chain (CKC) exercises on proprioception and physical activity level in pediatric patients with hemophilia.

METHODS

A total of 21 patients with hemophilia A who had at least one target knee joint were randomized into three groups: Study Group (SG, n = 7), Conventional Treatment Group (CTG, n = 7) and Control Group (CG, n = 7). The SG received a structured, lower limb-specific exercise protocol consisting of CKC exercises 2 days a week for 12 weeks, in addition to prophylactic treatment. The CTG received exercise training as described in the published literature. The CG continued to receive prophylactic treatment during the study period. Proprioception was measured using a digital goniometer before and after treatment in open and closed kinetic chain positions (CKCPs). The Five Times Sit to Stand (STS), Timed Up and Go (TUG) and Functional Independence Score in Hemophilia were used for the assessment of physical activity level.

RESULTS

A significant pre/post-treatment difference was found among the groups in proprioception (p = .001) and physical activity level (TUG p = .008, STS p = .001, FISH p = .006). Improvements in proprioception and physical activity level were greater in the SG compared to the other two groups (p < .05).

CONCLUSION

Compared to conventional exercise, the structured exercise protocol consisting of CKC exercise training produced improvements in proprioception and physical activity in patients with hemophilia A.

Most subjectively affected joints in patients with haemophilia - what has changed after 20 years in Germany?

BACKGROUND

In patients with haemophilia (PwH), most frequently affected joints are the ankle, knee and elbow. Due to improved factor therapy in the last decades, these previous findings have to be verified in Germany.

AIM

The aim of this study is to detect the most affected joint, evaluate the significance of the source of pain and determine the point prevalence of back pain in Germany today.

PATIENTS AND METHODS

In a retrospective study, data of n = 300 patients with severe moderate and mild haemophilia were evaluated regarding the most affected joint, the most common source of pain, and the point prevalence of back pain. An anamnesis questionnaire and the German Pain Questionnaire were used for this assessment.

RESULTS

The most affected joint in German PwH is still the ankle (41%), followed by the knee (27%) and the elbow (11%). The most common source of pain is also the ankle joint (32%). Back pain was also identified as one of the most common sources of pain, which is comparable to the elbow (elbow:15%; back:13%). The point prevalence in PwH for back pain was significantly higher compared to the general German population (P = .031).

CONCLUSION

Our data showed that the ankle is still the most affected joint and the most common source of pain in Germany. These results also showed the relevance of back pain as a pain source. The evaluations also demonstrated the high point prevalence of back pain in PwH. Future therapies should also focus on the spine because joint changes affect posture.

Effectiveness of physical exercise on postural balance in patients with haemophilia: A systematic review

INTRODUCTION

Balance training is important to improve balance and to decrease the risk of falls in patients with haemophilia (PWH).

AIM

To analyse the current knowledge about the effectiveness of physical exercise on postural balance in PWH.

METHODS

A systematic search for clinical trials, published before November 2021, was conducted using the following electronic databases: PubMed/MEDLINE, Web of Science, Embase, Wiley Online Library and the Cochrane Central Register of Controlled Trials (CENTRAL). Two independent reviewers extracted the data and assessed the risk of bias. The certainty of the evidence was analyzed using GRADE.

RESULTS

A total of ten studies involving 304 patients were included. The studies performed strength and balance exercises, and some included flexibility, mobilization, and/or aerobic exercises in their training programs. Postural balance was evaluated using a force platform and the one leg stand test was the most frequently used. Only five exercise programs achieved a significant increase in balance (pre-post) with a strength, postural balance, flexibility, and aerobic intervention. In general, the quality rate of the risk of bias was fair but the overall quality of the evidence across the studies was very low.

CONCLUSION

Five studies showed that there is a positive change in balance after the intervention. However, there is currently an unclear demonstration of evidence for the use of physical exercises to improve postural balance in people with haemophilia. Further studies with a higher methodological quality are needed.

Validity of the four-square step test in persons with haemophilia

INTRODUCTION

Recurrent bleeds into joints causes arthropathy leading to pain and reduced joint movement. This may cause a reduction in postural balance and increase the falls risk in patients with haemophilia (PWH). With an ageing PWH population the need to assess functional balance in clinic will be essential to monitor function and implement interventions to help maintain balance and prevent falls.

AIM

To assess the utility of the Four-Square Step Test (FSST) in PWH.

METHODS

80 PWH of all severity types were recruited and underwent a battery of outcome measures: FSST, Timed up & go (TUG), Short performance physical battery (SPPB), Haemophilia Activity List (HAL), ABC confidence questionnaire, and Haemophilia Joint Health score (HJHS). Demographics were collected, together with self-reported falls/trips history.

RESULTS

All 80 participants were able to complete all test measures. Median age 44.5 years. Number of participants reporting falls ranged from 23% in severe to 3% in mild. Recent trips 53% severe to 17% mild. Excellent Inter and intra-reliability, ICC of .981 (CI .953-.992), P < .001 and ICC .989 (.983-.993) P < .001, respectively. Strong correlations between FSST and TUG/ SPPB .753 and -.728, moderate correlation between FSST and ABC/HAL -.484, -.464 P < .01.

CONCLUSION

FSST is a valid and safe measure to use in PWH. It correlates strongly with other functional measures, has excellent inter and intra rater reliability. FSST correlates with age rather than severity type and provides information to the clinician on the speed/ability to change direction and clear an obstacle. ABC questionnaire was able to differentiate between severities and offers insight into patient confidence to move. SPPB had a ceiling effect with 52/80 scoring 12 and may not be suitable for PWH.

Modular reorganization of gait in chronic but not in artificial knee joint constraint

It is currently unknown if modular reorganization does occur if not the central nervous system, but the musculoskeletal system is affected. The aims of this study were to investigate 1) the effects of an artificial knee joint constraint on the modular organization of gait in healthy subjects; and 2) the differences in modular organization between healthy subjects with an artificial knee joint constraint and people with a similar but chronic knee joint constraint. Eleven healthy subjects and eight people with a chronic knee joint constraint walked overground at 1 m/s. The healthy subjects also walked with a constraint limiting knee joint movement to 20°. The total variance accounted (tVAF) for one to four synergies and modular organization were assessed using surface electromyography from 11 leg muscles. The distribution of number of synergies were not significantly different between groups. The tVAF and the motor modules were not significantly affected by the artificial knee constraint. A higher tVAF for one and two synergies, as well as merging of motor modules were observed in the chronic knee constraint group. We conclude that in the short-term a knee constraint does not affect the modular organization of gait, but in the long-term a knee constraint results in modular reorganization. These results indicate that merging of motor modules may also occur when changes in the mechanics of the musculoskeletal system is the primary cause of the motor impairment.NEW & NOTEWORTHY It is currently unknown if modular reorganization does occur if not the central nervous system, but the musculoskeletal system is affected. This study showed that in the short-term a knee constraint does not affect the modular organization of gait, but in the long-term a knee constraint results in modular reorganization. These results indicate that modular reorganization may also occur when changes in the mechanics of the musculoskeletal system is the primary cause of the motor impairment.

Static postural balance evaluation and an investigation of the relationship with joint health in children with severe haemophilia: a controlled cross-sectional study

INTRODUCTION

Recurrent hemarthroses disturbing force/movement control are likely to impair postural balance.

AIM

To investigate the possible changes in static postural balance parameters in children with haemophilia (CwH) and to reveal its relationship with Haemophilia Joint Health Score (HJHS).

METHODS

Twenty-one CwH aged 6-18 who had haemophilic arthropathy in at least one lower limb joint and 21 healthy peers were evaluated by using a force platform. Centre of pressure (CoP) signals were displayed as a map in both anteroposterior direction (APD) and mediolateral direction (MLD) by statokinesigram. Accordingly, the amplitude, velocity and standard deviation of CoP displacements along with the perimeter and ellipse area were measured. Assessments were made under eyes opened and eyes closed in bipedal stance for 60 s. Joint health and muscle strength were evaluated with HJHS and digital dynamometer, respectively.

RESULTS

Velocity and amplitude of CoP displacements in MLD were increased in CwH (p˂0.05). It was also found that these parameters were moderate correlated with the clinical score of the lower limb joints (p˂0.05). In CwH, standard deviation of CoP displacements in the APD was significantly higher in eyes closed, while standard deviation in MLD was significantly higher in eyes opened (p˂0.05).

CONCLUSION

Disturbances during bipedal stance reveal the need for balance evaluation in CwH. Increased mediolateral oscillations may be an early sign of disorders of the musculoskeletal system in CwH. In addition to improving joint health, postural balance exercises that increase MLD stability have to be included in the rehabilitation programme of CwH.

Effects of performing dual tasks on postural sway and postural control complexity in people with haemophilic arthropathy

INTRODUCTION

People with haemophilic arthropathy (PWHA) have impairments in postural control. However, little is known about the effects of demanding conditions, including the unipedal stance and dual tasks, on postural control in PWHA.

AIM

Determine the effects of performing dual tasks while in the one-leg stance on postural sway and postural control complexity in PWHA vs. healthy active (HAG) and non-active (HNAG) groups of individuals.

METHODS

Fifteen PWHA and 34 healthy subjects (18 active and 16 non-active) were recruited. Vertical (V), mediolateral (ML) and anteroposterior (AP) centre of mass signals were acquired using a 3-axis accelerometer placed at the L3/L4 vertebrae of subjects as they performed the one-leg stance under single and dual-task conditions. Sway balance and the complexity of postural control were studied via root mean square (RMS) acceleration and sample entropy, respectively. Increased complexity of postural sway was attributed to increased automatism of postural control.

RESULTS

RMS values for PWHA were higher than HAG under both conditions for the V and ML axes, and higher than HNAG under the dual-task condition for the ML axis. Sample entropy was lower in PWHA than healthy individuals under the dual-task condition for V and ML axes, and the single-task condition for the ML axis (P < .05).

CONCLUSION

PWHA had poorer postural sway and decreased postural control complexity when performing a one-leg stance than healthy people, especially when the dual-task condition was applied. These results may help to design new approaches to assess and improve postural control in PWHA.

Changes in Muscle Activity Patterns and Joint Kinematics During Gait in Hemophilic Arthropathy

Hemophilic arthropathy is the result of repetitive intra-articular bleeding and synovial inflammation. In people with hemophilic arthropathy (PWHA), very little is known about the neural control of individual muscles during movement. The aim of the present study was to assess if the neural control of individual muscles and coordination between antagonistic muscle pairs and joint kinematics during gait are affected in PWHA. Thirteen control subjects (CG) walked overground at their preferred and slow velocity (1 m/s), and 14 PWHA walked overground at the preferred velocity (1 m/s). Joint kinematics and temporal gait parameters were assessed using four inertial sensors. Surface electromyography (EMG) was collected from gluteus maximus (GMAX), gluteus medius (GMED), vastus medialis (VM), vastus lateralis (VL), rectus femoris (RF), medial gastrocnemius (MG), lateral gastrocnemius (LG), soleus (SOL), tibialis anterior (TA), semitendinosus (ST), and biceps femoris (BF). Waveforms were compared using the time-series analysis through statistical parametric mapping. In PWHA compared to CG, EMG amplitude during the stance phase was higher for LG (for both velocities of the CG), BF (slow velocity only), and ST (preferred velocity only) (p < 0.05). Co-contraction during the stance phase was higher for MG-TA, LG-TA, VL-BF, VM-ST, LG-VL, and MG-VM (both velocities) (p < 0.05). MG and LG were excited earlier (preferred velocity only) (p < 0.05). A later offset during the stance phase was found for VL, BF, and ST (both velocities), and BF and GMAX (preferred velocity only) (p < 0.05). In addition, the range of motion in knee and ankle joints was lower in PWHA (both velocities) and hip joint (preferred velocity only) (p < 0.05). In conclusion, the neural control of individual muscles and coordination between antagonistic muscles during gait in PWHA differs substantially from control subjects.

Neuromuscular control during gait in people with haemophilic arthropathy

INTRODUCTION

Effects of haemophilic arthropathy on neuromuscular control during gait are currently unknown.

AIMS

(a) To assess how haemophilic arthropathy affects the complexity of neuromuscular control during gait; (b) To investigate the relationship between complexity of neuromuscular control and joint impairment.

METHODS

Thirteen control subjects (CG) walked overground at their preferred and a slow velocity and thirteen people with haemophilic arthropathy (PWHA) walking at their preferred velocity. Surface electromyography (EMG) was collected from eleven leg muscles. Electromyography variance explained by muscle synergies (sets of co-activated muscles that can be recruited by a single signal) was calculated by the total variance accounted (tVAF). Three measures were used to evaluate complexity of neuromuscular control: (a) the number of synergies required for tVAF > 90%, (b) tVAF as a function of the number of muscle synergies, and (c) the dynamic motor control index (Walk-DMC). Impairment of ankle and knee joints was determined by the Haemophilia Joint Health Score (HJHS).

RESULTS

The same number of the muscle synergies was found for each group (P > 0.05). For both walking velocities tested, tVAF1 was higher in PHWA (P < 0.05). The Walk-DMC of PWHA was lower than that of the CG for both walking velocities (P < 0.05). For PWHA, no significant correlation was found between HJHS (sum knee and ankle) and Walk-DMC index (r = -0.32, P = 0.28).

CONCLUSIONS

These results indicate differences between PWHA and CG in the neuromuscular control of gait. The Walk-DMC and tVAF1 may be useful measures to assess changes in neuromuscular control in response to treatment.

Assessment of haemophilic arthropathy through balance analysis: a promising tool

The purpose of this study was to develop a tool able to distinguish between subjects who have haemophilic arthropathy in lower limbs and those who do not by analyzing the centre of pressure displacement. The second objective was to assess the possible different responses of haemophiliacs and healthy subjects by creating a classifier that could distinguish between both groups. Fifty-four haemophilic patients (28 with and 26 without arthropathy) and 23 healthy subjects took part voluntarily in the study. A force plate was used to measure postural stability. A total of 276 centre of pressure displacement parameters were calculated under different conditions: unipedal/bipedal balance with eyes open/closed. These parameters were used to design a Quadratic Discriminant Analysis classifier. The arthropathy versus non-arthropathy classifier had an overall accuracy of 97.5% when only 10 features were used in its design. Similarly, the haemophiliac versus non-haemophiliac classifier had an overall accuracy of 97.2% when only 7 features were used. In conclusion, an objective haemophilic arthropathy in lower limbs evaluation system was developed by analyzing centre of pressure displacement signals. The haemophiliac vs. non-haemophiliac classifier designed was also able to corroborate the existing differences in postural control between haemophilic patients (with and without arthropathy) and healthy subjects.

Posturographic and ankle muscle activation characteristics in patients with haemophilia

INTRODUCTION

The objective of this work was to examine the interrelations of posturographic and surface EMG (SEMG) characteristics of ankle muscles in patients with haemophilia while standing naturally.

METHODS

Surface EMG of five bilaterally recorded ankle muscles was conducted in 24 patients with haemophilia (PwH, age: 42 [11] years, mean [SD], 22 A, 2 B, 21 severe, 3 moderate) with median (quartiles) WFH orthopaedic joint score of 30 (20/39) points and 24 non-haemophilic controls (Con, age: 42 [12]). Force plate (IBS) signals were captured simultaneously during bipedal stance with eyes open. Load proportion of the left and right sides as well as heel and forefoot were calculated via four independent pressure transducers. Overall, weight distribution (WD) indices are reported with higher results representing a poorer WD.

RESULTS

Analyses of WD showed large differences between groups (PwH: 10.2 [5.4], Con: 5.2 [2.9], P < 0.001, d = 1.15). After clustering PwH, large effects (P = 0.02, η_p ²  > 0.16) were found for amplitude ratios of the lateral gastrocnemius (LG) muscle. In PwH, the degree of joint alteration of the right lower limb was associated with load proportion of the left side (ρ > 0.64, P = 0.001).

CONCLUSION

Patients with greater dysbalance showed higher forefoot loads and appeared to compensate their altered joint situations with considerably higher amplitude ratios of LG. Further studies should investigate whether therapeutic interventions could alter postural alignment and muscle activation and how these can influence patients' joint function and symptoms.

Programmed Sports Therapy (PST) in People with Haemophilia (PwH) "Sports Therapy Model for Rare Diseases"

Sports and exercise therapy becomes more and more integrated in the treatment plan of different diseases. Although the benefits of this therapy are of high quality evidence, e.g. in cardiovascular diseases, no concepts of sports therapy are available as a treatment option for rare diseases.

During the last eighteen years, we analyzed the situation as well as necessity, and developed a model, contents and the concept of the “Programmed Sports Therapy (PST)” for the treatment of PwH (people with haemophilia) as our model of rare disease. Many studies have shown that motoric skills are depressed in PwH, and that this gap to healthy people increases during age. The only way to reduce this progression is an appropriate therapy, adapted to the necessities of PwH. In haemophilia, in particular, physio- and sports therapy treatments should go hand in hand, the first in the acute phase after bleeding, the second later, after the acute phase has finished. One model, which considers all the different challenges, can be the cogwheel model presented here. Since haemophilia is a rare disease, new training concepts are necessary because classical group therapies are often impossible. PST based on the combination of sports therapy camps together with a supervised autonomous home training helps to directly bring the training to the trainee, in order to enhance key competences and improve the individual situation in PwH, and perhaps in patients with other rare diseases.

The experience and scientific data substantiate the success of “Programmed Sports Therapy (PST)” and even this can be a model for other rare diseases.

RCT of a 6-month programmed sports therapy (PST) in patients with haemophilia - Improvement of physical fitness

Physical fitness is of major importance for patients with haemophilia (PwH) but is highly influenced by bleeding episodes. Although some cohort studies describe an improvement of physical fitness after training intervention, randomized controlled studies (RCT) in PwH are still rare.

AIM

The aim of this study was to prove the enhancement of physical work capacity in PwH by programmed sports therapy (PST).

METHODS

This RCT includes a training period over six months. Sixty-four PwH with moderate (n = 5) to severe (n = 59) haemophilia A (n = 57) and B (n = 7) were randomized into two groups - training intervention group (IG) and control group (CG) by block randomization. Complex strength measurements, joint score, coordination check and a 12-min walking test were carried out before and after training intervention.

RESULTS

Significant differences were tested in M. triceps brachii (Δ+0.62 N kg(-1) ), biceps brachii (Δ+1.25 N kg(-1) ), latissimus dorsi (Δ+0.59 N kg(-1) ), rectus abdominis (Δ+0.51 N kg(-1) ), biceps femoris (right: Δ+0.68 N kg(-1) ; left: Δ+0.59 N kg(-1) ) and the quadriceps femoris (right: Δ+0.71 N kg(-1) ; left: Δ+0.55 N kg(-1) ) after intervention between the two groups (all p ≤ 0.003). Furthermore, an increase in distance (Δ+171.5 m) covered in the 12-min walking test (P = 0.011) was observed. Regarding one-leg stand, a significant improvement (P = 0.037) in the IG (Δ+2.2 s right leg) after intervention could be determined.

CONCLUSION

For the first time, a study with a corresponding number of adult PwH in a RCT-design showed that programmed sport therapy with specific instructions over 6 months has a positive effect on physical performance of PwH, independent of constitution and disease process.

The effects of repetitive haemarthrosis on postural balance in children with haemophilia

Sensory information from visual, vestibular and proprioceptive systems is necessary to control posture and balance. Impairment in proprioception due to repetitive joints bleeding may lead to a deficit in postural balance which, in turn, leads to high joint stress and risk of bleeding recurrence. Despite the increase in attention in this field during the past few years, the data concerning to how bleeds can affect postural control in children with haemophilia (CWH) remain scarce. This study aimed to evaluate the postural balance in CWH. Twenty CWH Haemophilia Group (HG) and 20 age-matched children Control Group (CG) were recruited to this study. A force plate was used to record centre of pressure (COP) displacement under four different postural conditions during quiet standing: eyes open on firm surface, eyes open on foam surface, eyes closed on firm surface and eyes closed on a foam surface. Variables of COP as sway area and mean velocity and in anterior-posterior (y) medio-lateral (x) direction were processed and for each variable sensory, quotients were calculated and compared between groups. No differences were found in visual and vestibular quotients variables between groups. A higher value was found in sway area variable on proprioception quotient in the HG when compared with CG (P = 0.042). CWH with repetitive joint bleed on lower limbs showed differences in postural balance when compared with non-haemophiliac children. The identification of early balance impairments in CWH can help us understand better the effects of bleeds inside joints on postural control and plan a more effective preventive and rehabilitative treatment.

Ankle muscle activation in people with haemophilia

Since normative surface EMG (SEMG) values for muscles acting at the knee joint are available for people with haemophilia, increasing interest is noticeable for other joints affected by haemophilic arthropathy. Adequate activity of shank muscles is an important key for appropriate postural control. The aim of this study was to determine differences in muscle activation patterns of lower leg muscles between people with and without haemophilia during upright standing. SEMG of tibialis anterior (TA), fibularis longus (FL), lateral (LG) and medial (MG) heads of gastrocnemius, and soleus (SO) muscles of both sides were recorded in 25 haemophilic patients (H) and 25 non-haemophilic control subjects (C) while standing on even ground. The Gilbert-Score was used to assign sides to major (H-MA) and minor (H-MI) affected ankle joints in H. To normalize the SEMG amplitudes, amplitude ratios (percentage of cumulated activity) were calculated. Compared to controls, TA ratios showed higher and MG reduced levels in both H groups (P < 0.01). In the H-MA subgroup of H, FL also joined the TA behaviour whereas SO had similar activation direction as MG. Although possible descending influences from the knee joints cannot be excluded, this can be interpreted as a compensational mechanism due to the severity of the orthopaedic status of the ankle, which with increasing heaviness is accompanied by reduced plantar flexion capability. However, ankle joint integrity appears to be reduced in H, with TA and MG seeming to play key roles for neuromuscular control of upright posture.

Role of exercise and physical activity on haemophilic arthropathy, fall prevention and osteoporosis

In older men with haemophilia, arthropathy resulting from a lifetime of intra-articular bleeding contributes to the loss of independence and increased morbidity that occurs with age. A regular exercise programme that incorporates aerobics, strength training and balance and flexibility activities is a key component of successful ageing, helping to improve functional mobility and reduce the risk of falls, osteoporosis and osteoporotic fractures. Because of the special challenges associated with haemophilia, which include both the underlying coagulopathy and, in many cases, extensive joint damage, patients beginning an exercise regimen should be referred to appropriately trained physiotherapists (preferably someone associated with a haemophilia treatment centre) for evaluation, education and instruction and follow-up. Various assistive devices may make exercise easier to perform and more comfortable.

Time and frequency analysis of the static balance in young adults with Down syndrome

The main objective of this study is to understand the differences in equilibrium control between normal subjects and those with Down syndrome. A total of 54 subjects participated voluntarily, divided into control group and Down syndrome group. The equilibrium of the subjects was tested under two conditions: bipedal support with eyes open and closed. The signals were analyzed in a time and frequency domain. The statistical parameters selected (i.e., RMS distance, mean velocity, mean frequency and sway area) to analyze the behavior of the center of pressures (CoP) are calculated employing the result of the combination of the time series data in both directions (i.e. resultant distance). In order to calculate the frequency bands produced by the displacements of the CoP, a Fast Fourier Transform of the data was performed. The group with Down syndrome showed poorer static equilibrium control than the control group in the time domain. In the frequency domain, we found differences between the groups in the distribution of energy in the frequency bands analyzed. In addition, we observed the existence of an interaction effect of the group and the condition tested (p<0.001). These findings show that in the absence of visual information, the control group increases the energy at low frequencies, while the group with Down syndrome decreases it. Additionally, the lower amount of energy observed in this band under the 'eyes closed' condition may serve to identify abnormalities in the functioning of the vestibular apparatus of individuals with Down syndrome and/or difficulties experienced by these individuals in extracting relevant information from this route.

Balance dysfunction in adults with haemophilia

The main focus of lower limb physical performance assessment in people with haemophilia (PWH) has usually been on function, muscle strength and joint flexibility. The impact of haemophilic arthropathy on balance and falls risk is relatively under-explored. The aim of this study was to evaluate balance and related performance in PWH compared with age and gender matched healthy controls. It involved a comprehensive suite of clinical and laboratory measures of static and dynamic balance, mobility, strength, physical activity and falls efficacy completed in 20 PWH (mean age 39.4, 100% male) and 20 controls. Fifty percent of PWH reported falls in the past 12 months. Moderate impairment of balance and related measures were identified in PWH compared with the controls, with an average 35% difference between groups. Significant differences were evident between groups on both clinical and laboratory measures, including measures of dynamic bilateral stance balance [limits of stability measures on the laboratory test, functional reach; (P < 0.001); dynamic single leg balance (Step Test, P < 0.001)], gait and mobility (gait speed, step width and turning measures on the laboratory test, timed up and go test; P < 0.001); muscle strength (timed sit to stand, P = 0.002; quadriceps strength, P < 0.001); and activity level and falls efficacy, (P < 0.004). The dynamic clinical and laboratory measures testing similar domains of balance, gait and mobility had moderate correlations (0.310 < r < 0.531, P < 0.01). Moderate impairments in balance, mobility and related measures were identified in PWH, compared with the control group. Clinicians should include assessments of balance and related measures when reviewing adults with haemophilia.