Posterior tibial tendon transfer in the spastic brain-damaged adult does not lead to valgus flatfoot.

BACKGROUND: We studied the possible development of valgus flat foot after transfer of the posterior tibial tendon to the lateral cuneiform, used for surgical restoration of dorsiflexion in brain-damaged adult patients with spastic equinovarus foot. METHODS: Twenty hemiplegic patients were reviewed with a mean postoperative follow-up of 57.9 months. Weightbearing radiographs, static baropodometry analysis and functional evaluation were used to assess postoperatively outcomes. RESULTS: On the operated side, weightbearing radiographs showed an absence of medial arch collapse and a symmetrical and physiological hindfoot valgus; static baropodometric analysis showed a reduced plantar contact surface with a pes cavus appearance. The surgical procedure yielded good functional results. Nineteen patients were satisfied with the outcome of their surgery. CONCLUSIONS: Our findings support that transfer of the posterior tibial tendon does not lead to valgus flat foot in the spastic brain-damaged adult, and is still a current surgical alternative for management of spastic equinovarus foot.

[Is electrical stimulation with voluntary muscle contraction of physiologic interest in aging women?]. / L'électrostimulation surimposée à la contraction musculaire volontaire présente-t-elle un intérêt physiologique chez les sujets âgés?

OBJECTIVE: To analyze the physiological effects of electrical stimulation with voluntary muscle contraction exercise in postmenopausal women. MATERIALS AND METHODS: Thirty-two females aged 62 to 75 years were randomly assigned to three groups to perform four activity sessions for six weeks: group ME (N =11) climbed up and down stairs, group ES (N =11) practised electrostimulation, and group ME + ES (N = 10) undertook both activities. Physiological adaptations of body composition (lean and fat masses and bone mineral density), muscular strength (isometric and dynamic), vertical jump and posturokinetic activities (balance and gait) were analysed. RESULTS: For the three groups, the isometric strength at angle 100 degrees (average increase right and left legs, ME: 19 N.m; ES: 4.5 N.m; ME + ES: 11.5 N.m), the dynamic strength at speed 60 degrees.s(-1) (average increase right and left leg, ME: 15 N.m; ES: 14 N.m; ME+ES: 18.5 N.m) and the vertical jump (ME: 23 mm; ES: 16 mm; ME + ES: 34 mm) increased contrary in the body composition and posturokinetic activities. Nevertheless, the group ME + ES adapted differently on some parameters of bone mineral density (P < 0.05) and dynamic strength (P < 0.01) in relation to the groups ES and ME. CONCLUSION: Electrostimulation with voluntary muscle contraction exercise could induce different physiologic adaptations compared with electrostimulation or voluntary muscle contraction exercise alone.

Effects of brisk walking on static and dynamic balance, locomotion, body composition, and aerobic capacity in ageing healthy active men.

This work analyses the short-term physiological and neurophysiological effects of a brisk walking programme in ageing, healthy, active men. Twenty-one men 63 to 72 years of age were recruited and separated into 2 groups. One group performed a walking programme (WP) (n = 11) and another served as control (C) group (n = 10). The walking programme lasted for twelve weeks and included five sessions per week. Several parameters were assessed before and after the programme for the WP group. The same tests were performed (separated by twelve weeks) in group C. During each assessment, the subjects were put through static and dynamic balance tests, spatio-temporal gait analysis, body composition measurements and determination of aerobic capacity and bone mineral density. The statistic analysis showed a significant improvement in dynamic balance performance, especially in lateral sway when the subjects kept their eyes open, an increase of VO(2) max and loss of fat mass in the WP group. However, no alterations appeared in spatiotemporal gait characteristics, static balance performance, lean mass or bone mineral density (total body and hip). According to these results, this walking programme may have positive effects on preventing ageing subjects from falling.

Neuromuscular effects of three training methods in ageing women.

AIM: The present study aimed to compare the effects of 3 strength development methods on muscular mass and muscular strength in healthy ageing women. METHODS: Thirty-two healthy women, 62 to 75 years old were randomised into 3 groups. The 3 groups performed 4 sessions a week of strength development for 6 weeks. The 1(st) group (SC) climbed up and down 300 stairs per session. The 2(nd) group (ES) followed an electrostimulation programme on the quadriceps muscles. The 3(rd) group (SC+ES) combined stair climbing with electrostimulation. Before and after the 3 programmes, the muscular mass of the leg was assessed using a biphotonic absorptiometry machine. Isometric (angle 20 degrees and 100 degrees ) and isokinetic (60 degrees /s and 240 degrees /s) knee extension torque was measured using an isokinetic dynamometer. RESULTS: None of the programmes changed the muscular mass. All 3 groups increased isometric (angle 20 degrees, p<0.001; angle 100 degrees, p<0.003) and isokinetic (60 degrees /s, p<0.0001; 240 degrees /s, p<0.0001) knee extension torque. None of the programmes appeared more efficient than the others for muscular mass or muscular strength. CONCLUSION: Six weeks of activity (SC, ES or SC+ES) improved the isometric and dynamic muscular strength in ageing healthy women. However, this period was too short to change the muscular mass. None of the activities presented a real advantage over the others in ageing women.

Influence of eye closing on the cardiovascular response to stand test on stable and unstable platforms.

UNLABELLED: Check if the stimulation of the leg muscles and neuro-sensorial system during stand test influence the cardiovascular response to stand test pre and post a 7 d HDT (4 subjects). METHODS: After 20 min supine, the subject stood for 10 min, and closed the eyes for 1 min. Then he stayed 2 min stand up on ant-posterior or lateral unstable platform and closed the eyes for 30 sec. The cerebral and lower limb flow were assessed by Doppler (skin fixed sensors) and also the cerebral to femoral flow ratio (CFR). RESULTS: All 4 subjects were tolerant, CFR increased similarly pre and post HDT. Post HDT eye closing increased leg muscle activity, and femoral flow increased more than pre HDT, on ant-post unstable platform. The trace of the body foot pressure point was much longer post HDT on the ant-post platform. CONCLUSION: Post HDT neuro-sensorial disadaptation may contribute to reduce the orthostatic tolerance at least in absence of visual references.

Comparison between three strength development methods on body composition in healthy elderly women.

The effects of three strength development methods (during 6 weeks) were assessed on the body composition in 32 women, 62 to 75 years old and randomised in 3 groups. The first group (SC) has climbed and come down 300 stairs per session. The second group (ES) followed an electrostimulation programme on quadriceps muscles. The third group (SC+ES) has combined the stairs climbing with electrostimulation. Body composition and bone mineral density (BMD) was assessed using Absorptiometry machine before and after the programmes. None of the programmes has increased significantly BMD. Nevertheless, the SC+ES group BMD enhanced more on the trochanter (p<0,05) and the two legs (p<0,05) than the SC and ES groups BMD (interaction group/time). The combined activity (SC+ES) would deserve to be tested on a longer period.

Cholesterol reduction and increased cardiovascular fitness following a 12 weeks brisk walking.

The effects of a walking training programme were assesed on 10 healthy, active men aged 63-69 years. Serum lipids, pulse and blood pressure, maximum oxygen consumption (VO2 max) and anthropometric parameters, were measured before and after this programme. There was a significant fall in LDL (p<0.02) and mean diastolic BP (p<0.005). In spite of the subjects's initial good level of fitness there was still an 8% rise in the mean VO2 max of the group. There was also a significant loss of body fat (P<0.01). These positive physiological effects suggest that brisk walking can be considered as a a useful activity for improving the fitness and general health in this age-range.

Are there differences in postural regulation according to the level of competition in judoists?

The aim of this work was to study the posturokinetic capacities and use of visual information by judoists according to their level of competition. Twenty male judoists aged between 16 and 19 took part. They were separated into two groups: those that competed at regional level and those that competed at national and international level. Static balance was measured on a force platform. No difference was seen between the two groups. However, it seems that visual information is more important to the higher level judoists. Perhaps the level of competition influences the sensory canals involved in balance.

Spectral analysis of adult dancers' sways: sex and interaction vision-proprioception.

In subjects of both sexes with or without dance training, dependence on vision and proprioception for postural control was studied by destabilizing these cues on a free seesaw. Fast Fourier transform processing allowed spectral frequency analysis of the platform sways recorded by an accelerometer. Two frequency bands of the total spectral energy were used: the lower (0 - 2 Hz) and the higher (2 - 20 Hz) frequency bands. Dancers were significantly less dependent on vision but use more proprioception than untrained subjects. Professional dance training appears to shift sensorimotor dominance from vision to proprioception, and this evolution seems more marked for males than females. Female and male dancers had similar dynamic performances, but for males, the better neuromuscular coordination may be associated with biomechanical factors.

Specificity of the monocular crescents of the visual field in postural control.

Postural reactions elicited by monocular visual stimulation in the temporal crescent of the visual field were studied in adult subjects in dynamic balance on a rocking platform. Circular translation of a visual scene was induced in the temporal crescent by the rotation of membrane prisms placed laterally to the stimulated eye. In anteroposterior balance, postural reactions are identical whichever eyes is stimulated: ventral extension of the body when the visual scene moves upwards and dorsal extension when it moves downwards. In lateral balance, postural reactions vary with the stimulated eye: extension of the right side of the body when the right eye is stimulated by an upward displacement of the visual scene, extension of the left side when the left eye is stimulated. This difference, which contrasts with the similarity of reactions elicited by the stimulation of either para-foveal fields, suggests that the most peripheral part of the nasal retina has a specific role in head and body stabilisation.

The contribution of vision in dynamic spontaneous sways of male classical dancers according to student or professional level.

We investigated the involvement of vision in the regulation of dynamic equilibrium in male children and young adults performing a physical activity requiring a high level of spatial skill: self-induced body sways of ballet dancers on a free unstable platform, 45 professional male dancers (Paris Opera) participated in the study. They included two student groups (beginners and confirmed) and two performer groups (adolescent and adult). They maintained their equilibrium on the platform under different visual and position conditions. The displacement of the seesaw platform were calculated from accelerometer measures. Fast Fourier transform processing of stabilograms allowed spectral frequency analysis. The total spectrum energy and the energies of the three frequency bands (0-0.5 Hz, 0.5-2 Hz, 2-20 Hz) were determined. For all groups, ANOVA indicated that values were higher for eyes-closed than for eyes-open conditions. The visual dependence differed according to age: for 14-year-old students the postural control for dynamic equilibrium was less visually dependent than for 11-year-old students. The 18-year-old dancers, although professional, were more dependent on vision than 14-year-old student dancers. These 18-year-old dancers were still adolescent because they had recently undergone growth acceleration which could disturb their proprioceptive references and internal body representations. Thus, visual input may dominate over the other sensory inputs in the regulation of postural control.

Visual contribution to self-induced body sway frequencies and visual perception of male professional dancers.

We studied the degree of dependence on vision, for postural control and for perception, among male adult dancers and untrained subjects. First, body sways were analyzed on a free seesaw platform. Fast Fourier transform processing allowed spectral frequency analysis of the platform sways recorded by an accelerometer. Secondly, a visual dependence test, the rod and frame test (RFT) was used. Professional dancers were significantly more stable and less dependent on vision for postural control and for perception than untrained subjects. Presumably, professional dance training strengthens the accuracy of proprioceptive inputs and shifts sensorimotor dominance from vision to proprioception. For the dancers, there was interaction between the RFT visual dependence and the visual control of posture: the less visual-dependent they were for the RFT, the more stable they were in dynamic balance conditions.

Lateral dynamic balance reactions to circular translation of the visual field.

Lateral sway of subjects in spontaneous dynamic balance conditions on a seesaw platform was measured during a visual stimulation monocularly produced by a rotating glass covered with a prism membrane. Prism rotation induced the perception of a circular translation of the whole visual field and an ocular pursuit movement. Therefore, the retinal slip that occurs in normal pursuit was cancelled. Strong stereotyped postural reactions were observed in a direction that depended upon both the vertical visual field deviation and the eye stimulated: upper position of the right visual field induced a leftward sway resulting from an extension of the right hemibody; symmetrical reactions occurred for the left stimulation. The results suggest that the postural reactions recorded depend on the isolated oculomotor activity and, in addition, on retinal afferences corresponding to the temporal crescent of the stimulated side, which orientates the postural reaction on the homolateral lower limb muscles.

Unusual vestibular and visual input in human dynamic balance as a motion sickness susceptibility test.

BACKGROUND: Motion sickness (MS) is commonly thought to arise from a sensory conflict. However, few quantitative methods based on this theory are available to detect MS susceptibility. HYPOTHESIS: It was asked whether the standardized unusual stimulation of a single sensory channel under quantified dynamic balance conditions in man could elicit a sensory conflict and therefore trigger motion sickness (MS) METHODS: Vestibular and visual channels were stimulated by galvanic current and rotating prismatic glasses, respectively. The moving platform used to create the requirements for dynamic balance conditions was chosen not only to worsen the malaise but also to obtain an objective measurement of the balance consequences of the stimulations. RESULTS: Both vestibular and visual stimulation, applied separately, elicited MS-like symptoms (in 56% and 73% of subjects, respectively) and stereotyped balance reactions. A relationship was found between subjective MS-like symptoms and objective measurements of dynamic balance performance. Subjects sensitive to unusual vestibular messages differed from the others by a greater increase in the parameters indicating a difficulty of balance whereas subjects sensitive to unusual visual messages were recognized by the strategy they used to balance themselves. CONCLUSIONS: These results demonstrated that a sensory conflict can trigger MS-like symptoms. We conclude that the measured parameters of a global somatomotor activity, such as the dynamic balance task proposed here, could be useful for objectively detecting subjects predisposed to MS, for training them and testing the efficiency of anti-MS drugs.

Sex-linked differences in equilibrium reactions among adolescents performing complex sensorimotor tasks.

Equilibrium reactions were compared between male and female adolescents (prepuberal and puberal), classified into two groups: those who had previously learned complex motor tasks (dance or acrobatics) and those with no particular training. Subjects stood (eyes open or eyes closed) on a free seesaw platform, the displacements of which were calculated from accelerometer measures. They were instructed to maintain a vertical position with their frontal plane either parallel (to measure antero-posterior oscillations) or perpendicular to the axis of the platform (to measure lateral oscillations). Girls had a better stability than boys as shown by the smaller displacement of their center of gravity. Untrained subjects, irrespective of sex, were the least stable. Subjects trained in acrobatics were more stable than dancers. Differences related to sex can be attenuated by physical training involving equilibrium exercises which suggests that moderate sustained training could reduce the incidence of falls in aged persons and in professionally exposed workers.

The effects of maturation on self-induced dynamic body sway frequencies of girls performing acrobatics or classical dance.

We investigated the effects of maturation on the dynamic body sways of healthy girls. Prepubertal and postpubertal girls practising professional physical activities requiring a good ability to maintain equilibrium (acrobats and dancers) were asked to stand on a free seesaw platform and the results compared to those for untrained age-matched girls. This platform (stabilometer) allows self-induced body sways. Stabilograms were obtained by a double integration of the angular acceleration from the recordings of the platform sways made with an accelerometer. Fast Fourier transform processing of stabilograms allowed spectral frequency analysis. The total spectrum energy and the energies of three frequency bands (0-0.5 Hz, 0.5-2 Hz, 2-20 Hz) were determined. ANOVA showed that, for all groups of different equilibrium activity and independent of visual input, prepubertal girls had higher energy values than postpubertal girls in the 0- to 0.5-Hz band whereas the opposite was true for 0.5- to 2-Hz band. Ballet dancers were more dependent than acrobats on visual inputs for the regulation of their postural control but were less dependent than untrained girls at both ages. Maturation seemed to shift body sways towards higher frequencies and the utilization of the cues of postural control was different according to the type of equilibrium activity practised by the subjects.

Anteroposterior dynamic balance reactions induced by circular translation of the visual field.

The anteroposterior sway of subjects under conditions of spontaneous dynamic balance on a wobbly platform was measured during visual stimulation by a visual target executing a circular trajectory in the frontal plane. The target was either a component of the whole moving visual scene or moving on a stationary background. With the former stimulation, obtained through the use of rotating prismatic glasses, every point of the visual field appeared to describe a circular trajectory around its real position so that the whole visual field appeared to be circularly translated, undistorted, inducing a binocular pursuit movement. Under these conditions, stereotyped anteroposterior dynamic balance reactions synchronous with the position of the stimulus were elicited. The latter stimulation consisted of pursuing a luminous target describing a trajectory similar to that of the fixation point seen through the rotating prisms on the same, this time stable, visual background. Although pursuit eye movements were comparable, as demonstrated by electro-oculographic recordings, no stereotyped equilibration reaction was induced. It is concluded that the translatory motion of the background image on the retina in the latter experiments contributed to the body's stability as well as to the perception of a stable environment.

[Effects of captopril on the cerebral blood flow in the hypertensive aged subjects]. / Effets du captopril sur le débit sanguin cérébral du sujet âgé hypertendu.

Cerebral blood flow (CBF) was measured in 13 subjects (4 men and 9 women, mean age +/- SD = 63 +/- 7) with moderate, uncomplicated and untreated hypertension and 11 normotensive subjects (6 men and 5 women, mean age +/- SD = 66 +/- 5). A second CBF measurement was performed in hypertensive subjects after a 60 days randomized double blind treatment with either captopril, 75 mg a day (n = 8) or placebo (n = 5). CBF was quantified using the 133Xe inhalation technic and 16 stationary detectors by hemisphere. Comparison of CBF values between hypertensive subjects before treatment and normotensive subjects demonstrated a decrease of CBF in the hypertensive group (49 +/- 9 vs 72 +/- 14 ml/100 g/min; p < 0.001). After the trial the results in the captopril group showed a significant fall in systolic (p < 0.001) and diastolic (p < 0.05) blood pressure and a significant increase in CBF (60 +/- 14 vs 49 +/- 11 ml/100 g/min; p < 0.05). In the placebo group there was no change in blood pressure and CBF (Table). [Table; see text] Our results demonstrate a decrease in CBF of uncomplicated and untreated elderly hypertensive subjects. This decrease is reversible under chronic treatment with captopril.