James K. Richardson

Unipedal stance testing as an indicator of fall risk among older outpatients

OBJECTIVE To test the hypothesis that a decreased unipedal stance time (UST) is associated with a history of falling among older persons. DESIGN Fifty-three subjects underwent a standardized history and physical examination and three trials of timed unipedal stance. SETTING The electroneuromyography laboratories of tertiary care Veterans Administration and university hospitals. SUBJECTS Ambulatory outpatients 50 years and older referred for electrodiagnostic studies. OUTCOME MEASURES UST and fall histories during the previous year. RESULTS Twenty subjects (38%) reported falling. Compared with the subjects who had not fallen, those who fell had a significantly shorter UST (9.6 [SD 11.6] vs 31.3 [SD 16.3] seconds, using the longest of the three trials, p < .00001). An abnormal UST (<30sec) was associated with an increased risk of having fallen on univariate analysis and in a regression model (odds ratio 108; 95% confidence interval 3.8, >100; p < .007). The sensitivity of an abnormal UST in the regression model was 91% and the specificity 75%. When UST was considered age was not a predictor of a history of falls. CONCLUSIONS UST of <30sec in an older ambulatory outpatient population is associated with a history of falling, while a UST of > or = 30sec is associated with a low risk of falling.

The Relationship between Electromyographically Documented Peripheral Neuropatny and Falls

Objective: To determine if the presence of an electromyographically demonstrated peripheral polyneuropathy involving the lower extremities is associated with falls.

Factors Associated With Falls in Older Patients With Diffuse Polyneuropathy

OBJECTIVES: To identify clinical factors associated with falls by older persons with polyneuropathy (PN).

Falls and gait characteristics among older persons with peripheral neuropathy

DeMott TK, Richardson JK, Thies SB, Ashton-Miller JA: Falls and gait characteristics among older persons with peripheral neuropathy. Am J Phys Med Rehabil 2007;86:125–132. Objective:To prospectively determine the frequency and circumstances of falls in older persons with peripheral neuropathy and to identify gait characteristics on smooth and irregular surfaces associated with falls in this same population. Design:This was a descriptive and observational study of a prospective group cohort. Spatial and temporal gait measures on smooth and irregular surfaces, as well as basic demographic and clinical data, were obtained in 20 older persons with peripheral neuropathy. Falls and fall-related injuries were then prospectively determined for 1 yr. Results:Thirteen of 20 (65%) subjects fell, and 6 of 20 (30%) subjects sustained a fall-related injury during the year of observation. Of the 76 reported falls, 69 (90.8%) were associated with a surface abnormality (irregular or slick). Gait measures on the smooth surface did not distinguish between fall groups. On the irregular surface, however, step-time variability tended to be higher for those subjects who fell than for those who did not (89 ± 29 vs. 64 ± 26 msecs, respectively; P = 0.077) and for those who were injured from a fall compared with those who were not injured (101 ± 21 vs. 71 ± 29 msecs, respectively; P = 0.038). Conclusions:Older patients with peripheral neuropathy have a high rate of falls, and these falls are often associated with walking on irregular surfaces. Gait analysis on an irregular surface may be superior to that on a smooth surface for detecting fall risk in this patient population.

Moderate peripheral neuropathy impairs weight transfer and unipedal balance in the elderly

OBJECTIVE To quantitatively assess the performance of elderly with and without moderate, electrodiagnostically confirmed peripheral neuropathy (PN) on tasks of weight shifting and maintenance of unipedal balance. PATIENTS AND METHODS A case control study with PN subjects selected from a computerized data bank of all patients who had undergone electrodiagnostic studies at a university-based referral center. Control subjects of similar age and same gender were selected from the same source. Clinical examination included neurological and gross motor components. Quantitative evaluation included testing while the subjects stood with a force plate under each foot. Center of reaction (CR) excursions and ground reaction forces were quantified in: (1) six trials as subjects transferred their weight from bipedal stance to unipedal stance, on command, and attempted to maintain it for at least 3 seconds; and (2) in two additional trials in which subjects held unipedal stance for as long as possible. RESULTS No subjects in either group had difficulty with level gait, a 180-degree turn, or required examiner assistance during an eyes-closed Romberg test. Biomechanical testing revealed that although the PN group used the same time to transfer their weight onto one foot as the C group, they achieved a significantly (1) lower rate of success in reliably maintaining 3 seconds of unipedal stance (.12 vs .58, p = .021), and (2) shorter mean maximum unipedal stance time (3.8 vs 32.3sec, p < .001). Furthermore, the PN group experienced greater difficulty in maintaining unipedal stance, as evidenced by significantly greater fluctuations in their ground reaction forces. CONCLUSIONS The demonstrated impairment in reliability of unipedal stance in elderly with PN likely contributes to their known high rate of falls. Furthermore, unipedal stance testing serves to sharpen the physical examination by verifying the functional significance of impaired distal sensation-a common finding in the elderly.

A Comparison of Gait Characteristics Between Older Women with and Without Peripheral Neuropathy in Standard and Challenging Environments

Objectives: To compare gait patterns in older women with and without peripheral neuropathy (PN) in standard (smooth surface, normal lighting) and challenging environments (CE) (irregular surface, low lighting).

Pilot Evaluation of a Novel Clinical Test of Reaction Time in National Collegiate Athletic Association Division I Football Players

CONTEXT Evidence suggests that concussion prolongs reaction time (RT). We have developed a simple, reliable clinical tool for measuring reaction time that may be of value in the assessment of concussion in athletes. OBJECTIVE To compare baseline values of clinical RT (RT(clin)) obtained using the new clinical reaction time apparatus with computerized RT (RT(comp)) obtained using a validated computerized neuropsychological test battery. DESIGN Cross-sectional study. SETTING Data were collected during a National Collegiate Athletic Association Division I collegiate football teams preparticipation physical examination session. PATIENTS OR OTHER PARTICIPANTS Ninety-four Division I collegiate football players. MAIN OUTCOME MEASURE(S) The RT(clin) was measured using a 1.3-m measuring stick embedded in a weighted rubber disk that was released and caught as quickly as possible. The RT(comp) was measured using the simple RT component of CogState Sport. RESULTS For the 68 athletes whose CogState Sport tests passed the programs integrity check, RT(clin) and RT(comp) were correlated (r = 0.445, P < .001). Overall, mean RT(clin) was shorter and less variable than mean RT(comp) (203 +/- 20 milliseconds versus 268 +/- 44 milliseconds; P < .001). When RT(clin) and RT(comp) were compared between those athletes with (n = 68) and those without (n = 26) valid CogState Sport test sessions, mean RT(clin) was similar (202 +/- 19 milliseconds versus 207 +/- 23 milliseconds; P = .390), but mean RT(comp) was different (258 +/- 35 milliseconds versus 290 +/- 55 milliseconds; P = .009). CONCLUSIONS The RT(clin) was positively correlated with RT(comp) and yielded more consistent reaction time values during baseline testing. Given that RT(clin) is easy to measure using simple, inexpensive equipment, further prospective study is warranted to determine its clinical utility in the assessment of concussion in athletes.

Interventions improve gait regularity in patients with peripheral neuropathy while walking on an irregular surface under low light

Objectives: To determine which, if any, of three inexpensive interventions improve gait regularity in patients with peripheral neuropathy (PN) while walking on an irregular surface under low‐light conditions.

Peripheral neuropathy: An often-overlooked cause of falls in the elderly

Preview Peripheral neuropathy affects about one in five older persons, yet it is often not recognized as a cause of falls. Why do patients with peripheral neuropathy fall? The authors, who have studied this subject extensively, describe specific impairments, explain simple clinical techniques to identify functionally significant nerve dysfunction, and suggest ways to help patients prevent further falls.

Gender, body mass and age as risk factors for ulnar mononeuropathy at the elbow

Factors that predispose patients to ulnar mononeuropathy at the elbow (UME) are poorly defined. We compared 112 electrodiagnostic reports which met criteria for definite or probable UME to 104 reports which excluded UME. Male gender was strongly associated with definite (OR = 6.9, 95% CI = 2.4–20.4; P < 0.001) and all UME (OR = 2.2, 95% CI = 1.2–4.1; P = 0.010) after controlling for age and body mass index (BMI). Among men, UME was associated with increasing age (P = 0.008) but not a decreased BMI. Women, however, demonstrated an association between decreased BMI and UME (OR = 2.3, 95% CI = 1.3–4.2 for BMI ≤22.0 versus >22.0). These findings, in conjunction with gender differences in ulnar motor nerve parameters among UME subjects and controls, suggest that the pathophysiology of UME differs with gender.