Is self-image, in reference to the gravitational vertical, altered in adolescent idiopathic scoliosis? A multicenter, single-blind, case-control study.

PURPOSE: Adolescent idiopathic scoliosis (AIS) is associated with perturbation of orthostatic postural control. In humans, orthostatic postural control is organized around the gravitational vertical (GV). Perception of the GV involves a bottom-up process (central integration of multisensorial information) and a top-down process that uses cognitive mechanisms relying on body image. This study hypothesized that AIS would be associated with an erroneous central representation of verticality. The objective was to demonstrate an altered top-down process of sense of verticality in AIS. METHODS: This multicenter, single-blind, case-control study evaluated 63 adolescent girls with AIS divided into two groups (major AIS (n = 31) and minor AIS (n = 32)) and 30 matched non-scoliotic adolescents. Participants scored their perception of trunk appearance in an upright position using a pictographic scale. The outcome measure was the difference between perception score and real trunk deformity. RESULTS: Participants with major AIS presented with misperception of their trunk appearance in an upright position when compared with those with minor AIS or controls. CONCLUSION: Adolescents with major AIS underestimate their trunk deformity in an upright position. This suggests an altered representation of body image, affecting top-down control of sense of verticality.

Immediate effects of talocrural and subtalar joint mobilization on balance in the elderly.

BACKGROUND AND PURPOSE: The aim of the present study was to evaluate the immediate effects of therapeutic mobilization of the talocrural and subtalar joints on ankle mobility and postural control in elderly subjects. METHODS: Nineteen subjects (83.1 ± 6 years, 159 ± 1 cm; 56.1 ± 9.7 kg - mean ± standard deviation) participated in this study. The centre of pressure (COP) displacements along the anterior-posterior and medial-lateral axes was recorded in static and dynamic conditions on a force platform before and after therapeutic mobilization of the feet and ankles without blinding the subjects. RESULTS: In static conditions, the sway area is reduced contrarily to dynamic conditions where the sway area is increased. In the two experimental sessions, subjects showed comparable COP displacements and the total length of the oscillations. Results demonstrated a significant improvement immediately after mobilization for ankle range of motion in dorsal flexion (right +4.7°; left +3.2°) and plantar flexion (right 5.2°; left +4.2°). CONCLUSION: These results suggested that postural control is improved in static conditions and decreased in dynamic conditions. Therapeutic mobilization of feet and ankles in the elderly provides an immediate improvement in joint range of movement in dorsal and plantar flexion.

Effects of a 6-week plyometric training program on performances in pubescent swimmers.

This study examined in pubescent swimmers the effects on front crawl performances of a 6-week plyometric training (PT) in addition to the habitual swimming program. Swimmers were assigned to a control group (n = 11, age: 14.1 ± 0.2 years; G(CONT)) and a combined swimming and plyometric group (n = 12, age: 14.3 ± 0.2 years; GSP), both groups swimming 5.5 h · wk(-1) during a 6-week preseason training block. In the GSP, PT consisted of long, lateral high and depth jumps before swimming training 2 times per week. Pre and posttests were performed by jump tests (squat jump [SJ], countermovement jump [CMJ]) and swim tests: a gliding task, 400- and 50-m front crawl with a diving start (V400 and V50, m · s(-1)), and 2 tests with a water start without push-off on the wall (25 m in front crawl and 25 m only with kicks). Results showed improvement only for GSP for jump tests (Δ = 4.67 ± 3.49 cm; Δ = 3.24 ± 3.17 cm; for CMJ and SJ, respectively; p < 0.05) and front crawl tests (Δ = 0.04 ± 0.04 m · s(-1); Δ = 0.04 ± 0.05 m · s(-1); for V50 and V400, respectively; p < 0.05). Significant correlations were found for GSP between improvements in SJ and V50 (R = 0.73, p < 0.05). Results suggested a positive effect of PT on specific swimming tasks such as dive or turn but not in kicking propulsion. Because of the practical setup of the PT and the relevancy of successful starts and turns in swimming performances, it is strongly suggested to incorporate PT in pubescent swimmers' training and control it by jump performances.

Comparison of maximal and spontaneous speeds during walking on dry land and water.

The aim of this study was to quantify spontaneous and maximal speeds on dry land and in water, in four modalities of walking [forward (F), backward (B) and lateral walking (L)], with chest immersion level. Lateral walking was studied with the upper limbs of the subject alongside the body with hands placed on the lateral face of the thighs (L1) and upper limbs tightened behind the back with the hands joined (L2). 16 males (age 22.8+/-1.8 years, height 178.1+/-6.1cm, body mass 73.5+/-6.6 kg) and 15 females (age 22.8+/-2.1 years, height 171.5+/-5.8 cm, body mass 69.2+/-9.3 kg) were evaluated using the four modalities of walking on dry land and in water. The speed increments between spontaneous and maximal speeds on dry land for F, B and L1 and L2 were 60.2%, 60.9%, 64.3% and 65.3% for males and 47.3%, 48.3%, 44.5% and 53.1% for females. In the water, these variation values for F, B, L1 and L2 for males were 44.6%, 26.1%, 48.8%, and 42.1%. The values for females were 31.7%, 21.6%, 32.8%, and 34.6%. Spontaneous and maximal speeds of walking were substantially reduced in water with the chest immersed, compared to speeds on dry land for the four modalities and the two genders. These findings may be used by therapists who utilize the various modalities of walking in aquatherapy.

An electromyographic study of human gait both in water and on dry ground.

The purpose of the present study was to define the degree of muscular activation while walking in water in order to aid rehabilitation therapists in their choice of exercises for daily clinical practice in aquatherapy. This study compares the electromyographic (EMG) activity of the rectus femoris, the soleus of the right lower limb and the contra-lateral lumbar erector spinae, during gait in water and on dry ground. The study was carried out on a group of seven healthy female subjects without past rachidian pathology. EMG recordings in water were taken with immersion to the umbilicus at "comfortable" speed. A total of five recordings were made at this speed, in water and on dry ground, with a one-minute rest between recordings. Integrated EMG results, averaged on eight gait cycles, show, for all the subjects, more erector spinae activity in water than on the ground (p<0.01). Soleus activity is greater during gait on dry ground for the whole group (p<0.01). For four subjects, the electromyographic (EMG) activity of the rectus femoris over the entire cycle is greater than that exhibited on dry ground. In the two experimental situations, no differences have been found either on amplitudinal peaks or on the shape of the patterns. The speed and gait cycle length are reduced in water (60% and 25%). Walking in water at an umbilical level increases the activity of the erector spinae and activates the rectus femoris to levels near to or higher than walking on dry ground. These data should be taken into account by the physiotherapist when designing a rehabilitation programme.