The Association of Grip Strength With Severity and Duration of Parkinson's: A Cross-Sectional Study.

BACKGROUND: Weakness is reported in Parkinson's but always unadjusted for recognized factors that influence muscle strength such as participants' age, gender, and body size. This may obscure the true association of Parkinson's with muscle strength. OBJECTIVE: To evaluate the relationship between grip strength, Parkinson's severity, and duration adjusting for these factors. METHODS: Age, gender, height, weight, grip strength, Unified Parkinson's Disease Rating Score (UPDRS) motor score, Hoehn and Yahr (H&Y) stage, disease duration, number of comorbidities and medications, Barthel score, Mini Mental State Examination (MMSE) score, and Malnutrition Universal Screening Tool (MUST) score were recorded. RESULTS: Fifty-seven of 79 (72%) people with Parkinson's resident in one town were recruited. Age, gender, height, and Parkinson's severity were the most significant determinants of grip strength. Each unit increase in UPDRS motor score and H&Y stage was associated with lower grip strength in univariate linear regression analyses adjusted for gender: -0.3 kg strength (95% confidence interval = -0.51, -0.09), P = .006 for each additional UPDRS point, and -3.87 kg strength (95% confidence interval = -6.54, -1.21), P = .005 for each additional H&Y stage. Disease duration was not associated with grip strength. In multivariate regression, Parkinson's severity remained strongly associated with grip strength (UPDRS score P = .09; H&Y stage P = .04). CONCLUSIONS: This is the first demonstration that increasing severity of Parkinson's was associated with weaker grip after adjustment for known influences on muscle strength. Participants' age, gender, and body size also had a significant impact on strength. Adjustment of reported values for all these factors is essential to allow accurate reporting of grip strength values in intervention trials and comparison between different groups.

Psychometric properties of 3 functional mobility tests for people with Parkinson disease.

BACKGROUND: Standardized outcome measures with high clinical utility are of paramount importance for clinical practice. OBJECTIVE: The purpose of this study was to examine interrater and intrarater reliability, construct validity, discriminant ability, and smallest detectable differences of the sit-to-stand test (STS), Timed "Up & Go" Test (TUG), and bed mobility test for people with Parkinson disease (PD). DESIGN: A cross-sectional, psychometric evaluation study was conducted. METHODS: A group of individuals with PD (PD group) and a group of individuals who were healthy (control group) were recruited through local PD groups and assessed in a movement laboratory in their "on" phase. Measurements of time to perform one STS, TUG, and bed mobility test were collected based on video recordings of that single performance. RESULTS: Thirty-eight individuals with PD (Hoehn and Yahr stages I-IV) and 19 age-matched control participants were recruited. Intraclass correlation coefficients for interrater and intrarater reliability for the PD group ranged from .95 to .99. Bland-Altman plots showed mean differences close to zero and narrow confidence intervals. Construct validity was established by means of moderate to good Spearman rho correlation coefficients with part III of the Unified Parkinson's Disease Rating Scale and the Hoehn and Yahr stage (range=.51-.63). Timings of all tests discriminated participants in the PD group from those in the control group and participants in the PD group in Hoehn and Yahr stages I and II from those in Hoehn and Yahr stages III and IV but did not discriminate "nonfallers" or those with single falls from repeat "fallers" or "nonfreezers" from "freezers." Applicable smallest detectable differences were established. LIMITATIONS: The results are not generalizable to people in the late stage of PD (Hoehn and Yahr stage IV: n=3). CONCLUSIONS: Timings of video recordings of 3 functional mobility tests with high clinical utility showed good psychometric properties for community-dwelling, ambulatory people with PD.

Slow Down and Concentrate: Time for a Paradigm Shift in Fall Prevention among People with Parkinson's Disease?

Introduction. We know little about how environmental challenges beyond home exacerbate difficulty moving, leading to falls among people with Parkinson's (PwP). Aims. To survey falls beyond home, identifying challenges amenable to behaviour change. Methods. We distributed 380 questionnaires to PwP in Southern England, asking participants to count and describe falls beyond home in the previous 12 months. Results. Among 255 responses, 136 PwP (diagnosed a median 8 years) reported falling beyond home. They described 249 falls in detail, commonly falling forward after tripping in streets. Single fallers (one fall in 12 months) commonly missed their footing, walking, or changing position and recovered to standing alone or with unfamiliar help. Repeat fallers (median falls, two) commonly felt shaken or embarrassed and sought medical advice. Very frequent fallers (falling at least monthly; median falls beyond home, six) commonly fell backward, in shops and after collapse but often recovered to standing alone. Conclusion. Even independently active PwP who do not fall at home may fall beyond home, often after tripping. Falling beyond home may result in psychological and/or physical trauma (embarrassment if observed by strangers and/or injury if falling backwards onto a hard surface). Prevention requires vigilance and preparedness: slowing down and concentrating on a single task might effectively prevent falling.

Impaired bed mobility and disordered sleep in Parkinson's disease.

The contribution of impaired mobility to disordered sleep in Parkinson's disease (PD) remains uncertain. We evaluated the sleep of 38 people with PD and observed their turning strategies. Most reported difficulty maintaining sleep and difficulty turning. Those who hip-hitched rated themselves more disabled and those who sat up had more severe PD than those who used support. Using multiple strategies was associated with sleep disturbance. As the ability to turn deteriorates, we recommend patients identify the single strategy least disruptive to sleep. Research must address whether improving mobility improves sleep quality.

Strategies used by people with Parkinson's disease who report difficulty turning.

PURPOSE: Difficulty turning (DT) is common in Parkinson's disease (PD). We set out to answer the questions: (1) do people who do and do not report DT differ in postural stability, heel strike, the use of support and step count when performing functional turns during everyday tasks, (2) is the structured observation of functional tasks an ecologically valid way of assessing an individual's ability to turn and (3) does a history of DT predict freezing and/or falls. METHOD: At home, 75 people (median age 75 years; PD duration 7 years) answered questions about DT, freezing and falls and completed a standard 180 degrees turn test and an everyday task necessitating spontaneous turns, later rated from video by blinded assessors. RESULTS: Forty-two people reported DT, of whom 86% reported frequent freezing and/or falls. Twenty-six people with DT and 15 without completed the functional task. Greater proportions of the former appeared Unstable (12 vs 1; P = 0.014), lacked Heel Strike (25 vs 9; P = 0.006) and Used Support (7 vs 0; P = 0.035): the former took more Turning Steps (medians 6 vs 4; P = 0.001). The 95% limits of agreement between step counts (functional vs standard turns) ran from -6.3 to 3.6 steps. Of 49 people with a history of freezing and/or falls, 36 (73%) reported frequent DT. CONCLUSIONS: People who report DT turn differently to those who report no problems. Standard turn tests poorly reflect step count during real-life turning, whereas unobtrusive structured observation reveals the turning strategies people use, so can guide rehabilitation. Reported DT is a sensitive indicator of freezing and/or falling, both indicators for physiotherapy.