Effects of strengthening the hip flexor muscles on walking ability and the locomotive syndrome rank test: An intervention study.

BACKGROUND: Locomotive syndrome is a state in which locomotive function is decreased due to musculoskeletal diseases. To extend a healthy lifespan, it is important to prevent falls and locomotive syndrome development accompanying aging by slowing the decline in walking ability. However, it is unclear whether hip flexor muscle strengthening improves walking ability and locomotive syndrome. This study aimed to examine the effect of hip flexor muscle strengthening on walking ability and the locomotive syndrome rank test. METHODS: Forty participants were enrolled. Before hip flexor muscle strengthening, maximum muscle strength on the exercised side was measured, and gait analysis and the two-step test were performed simultaneously. Participants were divided into a healthy group and a locomotive syndrome group based on the two-step test and were given hip flexor muscle training at least three days a week for six weeks. After completing the training, maximum muscle strength was measured and gait analysis was performed for all participants. The difference between the two-step test conducted pre- and post-training in the locomotive syndrome group was statistically analyzed. RESULTS: Twenty-two and 14 participants were included in the healthy and the locomotive syndrome groups, respectively. Hip flexion strength on the exercised side increased from 1.68 to 1.95 Nm/kg (p < 0.0001) and 1.04 to 1.21 Nm/kg (p = 0.0031) in the healthy and the locomotive syndrome groups, respectively. Step length, stride length and walking speed measured by gait analysis also increased in both groups. Consequently, the two-step test score improved from 1.17 to 1.30 (p = 0.0002) and the stage of locomotive syndrome improved in 9 participants (p = 0.041). CONCLUSIONS: Strengthening of the hip flexor muscles improved walking ability and the stage of locomotive syndrome. Therefore, strengthening of the hip flexor muscles is important for the prevention and improvement of locomotive syndrome.

Postural control before and after cerebrospinal fluid shunt surgery in idiopathic normal pressure hydrocephalus.

OBJECTIVES: This study aimed to confirm whether cerebrospinal fluid (CSF) shunting for idiopathic normal-pressure hydrocephalus (iNPH) improves postural instability, and to investigate the relationship between postural control and gait ability. PATIENTS AND METHODS: Twenty-three iNPH patients and 18 age-matched healthy controls (HC) were examined using the timed up and go (TUG) test and a force platform for calculating the center of pressure (COP) trajectory during voluntary multidirectional leaning and quiescent standing. We determined the patients' TUG values and COP trajectories before and after shunt surgery. RESULTS: Postural sway was greater in iNPH patients before shunt surgery and the TUG value was lower in iNPH patients before shunt surgery than in HC. Voluntary COP movements were significantly improved in iNPH patients at 1 week post-surgery, but no significant changes in quiescent standing were found between pre- and post-surgery. Significant correlations were found between the TUG value and voluntary COP movements in iNPH patients before and after surgery, but no significant correlations were observed between the TUG value and quiescent standing. CONCLUSION: Our results indicate that CSF shunting in iNPH patients may improve voluntary postural control and reduce the risk of falling. Impaired voluntary COP control in iNPH patients may reflect the underlying pathophysiological mechanisms of balance disturbance in iNPH.

The effect of CSF drainage on ambulatory center of mass movement in idiopathic normal pressure hydrocephalus.

BACKGROUND: Although gait and balance disturbances are core symptoms of idiopathic normal pressure hydrocephalus (iNPH), the ambulatory center of mass (COM) movements in patients with iNPH remain unclear. We aimed to clarify the ambulatory COM movements using an accelerometer on the patients' lower torsos and to investigate the changes in COM movement after cerebrospinal fluid tap tests (TT) and shunt surgeries (SS). METHODS: Twenty-three patients with iNPH and 18 age-matched healthy controls (HCs) were recruited. A triaxial accelerometer was fixed with a belt onto each participant's torso at the L3 vertebra level. We assessed each patient's 10-m gait before TT, 3 days after TT, and 1 week after SS. RESULTS: Compared to the HCs, the patients exhibited decreased gait velocities, increased step numbers, and increased step times. Their movement trajectory amplitudes (i.e., the COM movements) were increased in the medial/lateral direction and decreased in the vertical direction. They also exhibited greater variability (measured as coefficients of variation) in step time and movement trajectory amplitude in both the medial/lateral and vertical directions. The patients' gait parameters were significantly improved after TT and SS. SIGNIFICANCE: Our results suggest that iNPH-associated gait disturbances could cause abnormal ambulatory COM movements and that these disturbances are mitigated by TT and SS.

Postural instability differences between idiopathic normal pressure hydrocephalus and Parkinson's disease.

OBJECTIVES: We investigated the differences in postural control disability between idiopathic normal pressure hydrocephalus (iNPH) and Parkinson's disease (PD). PATIENTS AND METHODS: Twenty-seven iNPH patients, 20 PD patients, and 20 healthy controls (HCs) were examined using the Timed Up and Go test (TUG) and a force platform for recording the center of pressure (COP) trajectory during quiescent standing and voluntary multidirectional leaning (forward, backward, right, and left for 10 s each). RESULTS: In the leaning task, postural control in PD patients was impaired during forward and backward leaning, whereas postural control in iNPH patients was impaired in all directions. In particular, postural control during right and left leaning was significantly worse in iNPH patients than in PD patients. No significant difference was observed between iNPH and PD patients in TUG and postural sway during quiescent standing. CONCLUSION: Our results showed that the characteristics of impaired voluntary COP control in iNPH and PD patients might reflect pathophysiological differences in postural instability for each disease. In particular, postural instability during right and left leaning in iNPH patients may be responsible for wider steps and a higher risk of falling.