The Postural Control in Patients After Total Hip Replacement
Condition: Total Hip Replacement
Study type: Interventional

Summary: 
      Total hip replacement (THR) is the procedure which can improve the quality of life in
      patients with osteoarthritis. However, deficits in static stability and impairment of the
      lower limb efficiency can be observed even several months after procedure. The aim of this
      study was to investigate the static balance of the standing position in patients treated by
      THR.
    

Detailed description: 
      The balance platform and one leg standing test (OLS) were used to assess the static balance.
      The postural balance tests were performed on the Metitur Good Balance platform. Static
      balance tests on balance platform were performed in several position with different foot
      placement like: normal standing with eyes open (NS EO) and eyes closed (NS EC) position,
      tandem position (TP), second form of tandem position (2TP) and one leg standing position
      (1L). Participants were asked to maintain the motionless upright position with both arms at
      their sides and eyes staring at a target in front of them.

      During the normal standing (NS) position the patient stood on the platform barefoot with the
      feet placed parallelly (symmetric position of feet) with a 20 cm distance between them. The
      length of the trials with EO and EC was 30 seconds each.

      In TP (tandem position) the width of base of support was narrowed down significantly,
      therefore test lasted only 10 s. During the test in TP one foot was placed directly in the
      front of the other (on the line) and the heel of the front foot was touched the toes of the
      rear foot. Tests were performed tests in TP with the left foot in front (TLF) and with right
      foot in front (TRF) separately. In THR group the placement of the operated limb in the front
      stance was called the TOF test, while the placement of the non operated limb in the front
      stance was called the TNF test. The results obtained in TOF position and TNF position were
      compared with tandem control index (TC - mean of results obtained from control group in TLF
      and TRF positions).

      In 2TP alternately left or right foot was places in front of the other, but the feet were
      placed on both sides of the line dividing platform to two parts (line was tangent to the
      medial edge of feet). The length of exercise was 20 s. Analogically to the tandem test,
      patients were examined with the operated (2TOF) and non operated limb (2 TNF) in the front.
      Results were compared to the second tandem control index (2TC) representing the mean results
      of the control group as was described above.

      When testing one leg standing position on the balance platform, the patients were asked to
      raise one foot half the level of the calf of the supporting leg but not touching the stance
      limb. The trial lasted for 5 s. The test was stopped when the subject used his arms (touched
      the handrail) or used the raised foot (touched the floor). Usually after 2 failed attempts or
      fear of falling down procedure was stopped and results was not recording. The results of the
      patients after THR when standing on the operated (1 O) and non operated (1 N) leg were
      compared to the index denoting the mean results of the control group (1 C).

      During the static tests we analyzed the mean velocity of sway of the center of feet pressure
      (COP) in the frontal plane (X, mm/s) and in the sagittal plane (Y, mm/s) and the value of the
      middle of spectrum in the same planes. The spectrum is characterised by two co-dependent
      variables such as frequency (Hz) and the excursion (mm).

      During the one-leg standing test (OLS) the time of maintain this position by the patients was
      measured. The placement of the limbs was the same as in the case of the balance platform
      test. Subjects performed 3 trials on each lower limb. Time ended when subject either: loosed
      balance and touched raised foot the floor, moved supporting leg on the ground, a significant
      loss of balance or a maximum of 60 s had elapsed. Results achieved by the subjects after THR
      on both operated (OLS-O) and non operated limbs (OLS-N) were compared with the index of the
      control group (OLS-C: mean result of the tests performed on the left and right legs).
    

Intervention name(s): Static Posturography; One-leg standing test (OLS)
Intervention type(s): Other; Other
Intervention description(s): The balance platform (Good Balance by Metitur) and one leg standing test (OLS) were used to assess the static balance. OLS test was performed on left and right foot separately. The static posturography was performed with several various positions of feet. Position : normal standing with eyes open and eyes closed - an upright standing with feet placed parallel 20 cm apart for 30 s. Position: tandem - a stance with one foot placed ahead of the other for 10 s. Position: second form of tandem - a stance with one foot placed ahead of the other with feet placed on both sides of the line dividing platform to two parts for 20s. Position: one leg standing: stance on the one leg for 5 s.; During the one-leg standing test (OLS) the time of maintain this position by the patients was measured. The placement of the limbs was the same as in the case of the balance platform test. Subjects performed 3 trials on each lower limb. Time ended when subject either: loosed balance and touched raised foot the floor, moved supporting leg on the ground, a significant loss of balance or a maximum of 60 s had elapsed. Results achieved by the subjects after THR on both operated (OLS-O) and non operated limbs (OLS-N) were compared with the index of the control group (OLS-C: mean result of the tests performed on the left and right legs).
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Diagnostic
Keywords: total hip replacement; static disbalance