Masahiko Wakasa

Foot Pressure Pattern and its Correlation With Knee Range of Motion Limitations for Individuals With Medial Knee Osteoarthritis

OBJECTIVE To determine the foot pressure pattern of individuals with medial knee osteoarthritis (OA) and to analyze its relation with knee flexion/extension range of motion. DESIGN Descriptive. SETTING Rehabilitation center. PARTICIPANTS Individuals with unilateral, painful medial knee OA (n=50; mean age, 75y; OA group) were enrolled as subjects, and young, healthy persons (n=50; mean age, 28y; young group) and elderly persons (n=44; mean age, 74y; elderly group) without any pain, deformity, or apparent OA changes in either knee were enrolled as controls. INTERVENTION Walking 10m at a comfortable speed. MAIN OUTCOME MEASURES Partial foot pressures as percentages of body weight (%PFP), anteroposterior length of the center of pressure (COP) path as a percentage of foot length (%Long), transverse width of the COP path as a percentage of foot width (%Trans), knee flexion/extension range of motion (in the OA group). RESULTS The %PFP values for the heel and hallux, %Long, and %Trans were all significantly lower in the OA group than in controls (P<.001, all). Within the OA group, a limited range of knee extension was significantly associated with a short %Long (P<.001) but not with %Trans. CONCLUSIONS Individuals with medial knee OA exhibited low pressure on the heel and hallux and short %Long of the COP path, and limitation of knee extension was associated with shortness of %Long. The shortness of %Long in the OA group likely resulted from insufficient knee extension during the heel-contact phase associated with low pressure on the heel. %Long is a useful parameter in gait analysis by using a foot pressure measurement system.

The Time-dependent Changes in EMG Recorded from the Medial Gastrocnemius of Young and Elderly Amputees.

[Purpose] Dysfunction of lower extremity muscles is one risk factor of falls for amputee patients. However, the change in muscle activity pattern and balance ability of amputees who have no experience in standing with prosthesis during the period from prosthesis fitting to regaining the ability to walk has never been studied. Therefore, the objectives of the present study were to elucidate changes over time in the muscle activity pattern and walking speed from first prosthesis fitting to hospital discharge. We also investigated the differences of muscle activity during standing between younger and elderly amputee patients. [Methods] Electromyography measurements were performed on the gastrocnemius of the intact leg during standing. The test subjects were asked to shift their center of gravity forward. [Results] Two unique patterns of gastrocnemius activities were observed over time. In a younger patient, the amount of muscular activity of the gastrocnemius gradually increased over time. In an elderly patient, however, the amount of muscular activity of gastrocnemius gradually decreased over time. [Conclusion] The time-dependent changes in gastrocnemius muscle activities are indicative postural control ability. Therefore, understanding the time-dependent changes in muscle activities during rehabilitation and the differences of postural control between younger and elderly patients would contribute to the development of effective rehabilitation programs for each patient.

Relationship between mobility and arousal level after waking up

Background and Purpose:Falling is an unexpected event for older adults, but few studies have investigated falls related to arousal levels and mobility immediately after waking up in the morning. Therefore, the purpose of this study was to clarify the possible relationship of arousal level and mobility with falls in the early morning hours. Methods:We investigated both arousal levels and mobility of 14 community-dwelling older adults after waking up, from 4:00 AM until 2:00 PM. Mobility and arousal levels were evaluated through the following tests: Timed Up and Go, Functional Reach, postural sway, and critical frequency of fusion. Baseline of mobility and arousal levels were measured before sleep and after 5 hours of sleep. Immediately after waking up, each participants mobility and arousal levels were remeasured and then also remeasured 2 hours later, 6 hours later, and 10 hours later, respectively. Stanford Sleepiness Scale was also chosen to measure the internal state of subjective sleepiness and it was measured 7 times at 2-hour intervals after the participants woke up from sleep. Results:Significant differences were found between before sleep and after awakening in the score of Timed Up and Go test and Stanford Sleepiness Scale. The speed of Timed Up and Go test after awaking was slower than that before sleep. The Stanford Sleepiness Scale showed high states of sleepiness. Conclusion:We found that the decrease in arousal level in the early morning may affect mobility. The awareness of the degree of arousal levels may increase fall prevention in older adults in the early morning hours.

Residual effects of zolpidem, triazolam, rilmazafone and placebo in healthy elderly subjects: a randomized double-blind study.

With current hypnotic agents, next-day residual effects are a common problem. The purpose of the present study was to evaluate the residual effects of the commercially available hypnotics - zolpidem, triazolam, and rilmazafone - on the physical and cognitive functions of healthy elderly people in the early morning and the day following drug administration. In this study, the next-day residual effects of zolpidem, triazolam, and rilmazafone, following bedtime dosing in elderly subjects, were evaluated. Women (n = 11) and men (n = 2) aged 60-70 years received a single dose (at 23:00) of one of these, zolpidem 5 mg, triazolam 0.125 mg, rilmazafone 1 mg and placebo in a randomized, double-blind, crossover design. Measures of objective parameters and psychomotor performances (Timed up and Go test, Functional Reach Test, body sway test, critical flicker fusion test, simple discrimination reaction test, short-term memory test) and subjective ratings were obtained at 04:00, 07:00, and the next time of the day. All hypnotics were generally well tolerated; there were no serious adverse side effects and no subjects discontinued the evaluations. Compared to placebo, zolpidem and rilmazafone had good results on the Functional Reach Test. Although subjective assessments tended to be poor in the early morning, rilmazafone significantly improved the body sway test in the other hypnotics. A single dose of zolpidem 5 mg and triazolam 0.125 mg did not have any next-day residual effects on healthy elderly subjects. Residual effects appeared to be related to the compounds half-life and the dose used. Rilmazafone 1 mg exhibited steadiness in static and dynamic balance and seemed to be more favorable for the elderly with early morning awakening.

Foot pressure pattern, hindfoot deformities, and their associations with foot pain in individuals with advanced medial knee osteoarthritis

This survey clarified foot pressure patterns and hindfoot deformities in individuals with advanced knee osteoarthritis (OA) and analyzed their associations with foot pain. Sixty-four individuals with unilateral knee OA who underwent total knee arthroplasty (TKA) were divided into the following groups: no foot pain (n=26; men:women, 4:22; mean age, 73.7 years), foot pain resolved after TKA (12; 2:10; 75.8), and foot pain remaining after TKA (26; 4:22; 74.7). Elderly individuals without pain or deformity in either knee (54; 10:44; 74.3) were controls. Navicular height ratio of the medial longitudinal arch, leg-heel angle, and partial foot pressure as the percentage of body weight (%PFP) were calculated.%PFPs of the medial and lateral heel regions before TKA were significantly lower for the no foot pain group than for controls. One year after TKA, %PFP improved significantly. In the foot pain resolved group, before TKA, the leg-heel angle was significantly higher, and%PFPs of the medial and lateral heel regions and navicular height ratio before TKA were significantly lower than those of controls. One year after TKA, all parameters improved significantly. In the foot pain remaining group, similar abnormalities were observed before TKA; however, significant improvement was only observed for%PFP of the medial heel region 1year after TKA. More than half of the patients with advanced knee OA had foot pain. This improved in approximately one-third, 1year after TKA. Hindfoot deformities are probably associated with foot pain in individuals with advanced knee OA.

Ultrasonographic Morphologic Changes of the Central Aponeurosis of the Rectus Femoris Muscle in Individuals With Knee Osteoarthritis.

Abstract The aim of this study was to clarify the morphologic characteristics of central aponeurosis (CA) of the rectus femoris (RF) muscle in individuals with medial knee osteoarthritis (OA). Forty legs in 26 individuals with medial knee OA (OA group), 41 legs in 21 elderly individuals (elderly group), and 40 legs in 20 young individuals (young group) were investigated. We measured the following 4 parameters: (1) ratio of CA length, expressed as the percentage of RF length; (2) CA morphologic type (curved, straight, S-shaped, or irregular); (3) CA direction, defined as the direction of the line from the anterior to posterior ends of the CA (lateral or medial); and (4) intercondylar distance (ICD). Ratio of CA length in the OA group was significantly smaller than that in the other 2 groups. The curved CA type was significantly more frequent in the young group than in the other 2 groups. The irregular type was observed in only 7 legs in the OA group. In the young group, CA direction was classified as medial in all cases. Laterally directed CA was observed only in the OA and elderly groups. Within the OA group, ICD in laterally directed CA was significantly larger than that in medially directed CA. Central aponeurosis observed in the RF muscle in individuals with medial knee OA is shorter and sometimes shows an irregular shape. Laterally directed CA is associated with increased ICD in knee OA. Attention should be given to the tendon-aponeurosis complex in individuals with medial knee OA.

Foot Pressure Pattern During Walking in Individuals with Anterior Cruciate Ligament Injury.

BACKGROUND We evaluated foot pressure distribution during walking in individuals with anterior cruciate ligament (ACL) injury. METHODS Our study included 24 ACL-deficient patients and 22 healthy young adults as controls. The former group was divided into the dominant-side ACL-deficient group (n = 17) and the nondominant-side ACL-deficient group (n = 7). The following parameters were calculated from the path of the center of pressure (COP) on a foot pressure distribution system: percentage of COP (%COP; the ratio of anteroposterior COP path length to foot length), percentage of COP locus area (%CLA; the ratio of the area encompassed by the COP path and a line between the start and end points of the COP path to foot area), and the value of maximum amplitude of COP (MACOP; the maximum perpendicular length from the COP path to a line between the start and end points of the COP). RESULTS In the nondominant-side ACL-deficient group, %COP (P = .026), %CLA (P = .001), and MACOP (P =.012) on the injured side were significantly lower than those in the nondominant leg side of the control group. No significant differences were found between the dominant-side ACL-deficient group and the control group. CONCLUSIONS Shortening of the COP trace in the nondominant-side ACL-deficient group may be associated with knee flexion during walking at heel contact. Because the parameters used herein can be obtained easily, repetitively, and quantitatively, they should be used in evaluating the gait of patients with ACL-deficient knees.