Institute for Work & Health Research Update: Upper Extremity Disorders and the Workplace David Rempel, MD, MPH, FACOEM Division of Occupational and Environmental Medicine University of California, San Francisco Ergonomics Program Center for Occupational and Environmental Health University of California, Berkeley 1 4 Overview ACOEM Guidelines Patient symptom reporting Trigger finger CTS controversies Repetitive, forceful hand activities Computer work 2 5 Trigger Finger Steroid Injections Non-diabetics Steriod: 86% effective (1-2) Diabetic Steroid: 63% effective Placebo: 53% effective NS Baumgarten, et al, JBJS, 27; 89:264 3 6 David Rempel WOHC 29 1
Trigger Finger Injection 2 mg methyprednisolone & lidocaine Not at prox finger crease palmar to MCP Not subcutaneous in sheath CTS Vitamin B6 (Pyridoxine) Not justified unless patient demonstrates B6 deficiency Well controlled studies demonstrate no effect Amadio 1985, Stransky 1989, Spooner 1993 7 1 CTS Provocative Tests CTS NSAIDs sensitivity specificity Phalens 61-88 % 8-84 % Tinel 14-74 % 35-94 % Monofilament 82 % 86 % Carpal compression 82 % 99 % At 4 weeks: no difference in symptom severity between NSAIDs, diuretic, or placebo Chang MH Neurology,1998 Tetro et al. J Hand Surg 1998 Koris et al. 199 8 11 CTS treatment - Update CTS Exercises Vitamin B6 NSAIDs Pregnancy Activity modification PM wrist splint Steroid Injection Surgery Tendon gliding mixed to no value Baysal et al., 26 Akalin et al., 22 9 12 David Rempel WOHC 29 2
CTS - Pregnancy Sx in third trimester 2% have CTS sx Splints ( steriod injection) 86% improve postpartum CTS Steroid Injections 77% Initial relief 25 5 % sustained (3-12 mo) relief Best candidates Numbness intermittent itt t No motor weakness/atrophy <2 ms prolongation of DSL/DML Improvement confirms diagnosis 13 Dammers 1999, 24, 26; Hui 26; Akelman 24; Demirci 22; Ucan 26 16 CTS PM Splinting Neutral wrist ( to extension) Effective up to 3 months Manente et al., 21 O Connor et al., 23 Premoselli et al., 26 CTS Steroid Injection 2-6 mg methyprednisolone & lidocaine 14 17 CTS Ultrasound CTS Surgery min/day X -2 days Positive outcomes in best studies [Fail splinting and refuse injection] Ebenbichler et al., 1998 Bahktiary et al., 24 (no control) [Grundberg 1983] Nerve Conduction Study Normal values vary Median wrist, ulnar wrist, ulnar elbow Negative test does not exclude CTS Positive Steriod Injection Response [ MRI or Ultrasound ] 18 David Rempel WOHC 29 3
CTS - Surgery Plant Cutter in Nursery Open Endoscopic Mini open Mini open Pillar pain with Open More complications with Endoscopic and Mini Early RTW: Endoscopic and Mini open No difference at 6 months Selection: depends on hand surgeon s experience and patient preference Before www.me.berkeley.edu/ergo/ After 19 22 CTS Work Risk Factors CTS & Tendonitis: Dental Hygiene Repeated forceful griping > 1 kg force [Repetition less important] (Roquelaure, 1997; 28) Vibration (Palmer 27) Computer use (Gerr 22; Anderson 23; Atroshi 27) Force (N) 5 4 3 2 1 Peak Thumb Pinch Force (N) Students Dentists 3DB 3ML 14DL 14MB 19DB 19ML 3DL 3MB Tooth area [Dong H et al. J Period 26] 2 23 Workplace Interventions to decrease grip force Nursery work Dental hygiene (Hui, 26; 26) Overhead drilling (Rempel, 28) Periodontal Curettes Decrease Pinch Force Instrument Design Tip sharpness Barrel Width Surface texture Tool weight [Hui D et al. JADA 26] 21 24 David Rempel WOHC 29 4
Tool diameter & weight Hui D et al. JADA 26 Computer Work Pinch Force 7 8.5 1 11.5 4 35 3 25 2 1 5 Force (N) Pinch F Peak Median Static ( ) Pinch Force 18 21 24 4 35 3 25 2 1 5 rce (N) Pinch For Peak Median Static Systematic Reviews Brewer et al. 26 Gerr et al. 26 IJmker et al. 27 Palmer et al. 27 Verhagen et al. 27 Diameter (mm) Weight (g) 25 28 Overhead Drilling Risk Factors: Computer Use and Upper Extremity Disorders [Gerr et al., 26] Biomechanical Head rotated to side Shoulder flexion Mouse use Keyboard above elbow Non-neutral neutral wrist Telephone use Work Organization -long hours on computer -limited rest breaks -deadline work -extensive overtime -surges in workload -low decision latitude Hand force = 2 kg 26 Psychosocial Other Job pressure -bifocal use Fear of job loss -children at home Low supervisor support -female Low coworker support -thyroid conditions 29 Overhead Drilling Andersen JH et al. 23 1 year Danish prospective study of 948 trade union members Questionnaire and clinical interview Computer use does not pose a severe occupational hazard for developing CTS Hand force = 1 kg [Rempel et al. 27] 27 3 David Rempel WOHC 29 5
Andersen JH et al. 23 Marcus, et al 22 and Gerr et al, 22 Logistic Regression: Incident Case of Possible R CTS (N=173) Personal Characteristics Negative affect.9(.6-1.5) Age 1.1 (.9-1.3) Female 1.6 (1.1-2.4) * BMI 1.1 (.6-2.3) Physical activity 1.1 (.8 1.5) Medical disorder 1.7 (1.-3.1) * Smoking 1.7 (1.2-2.4) * Accident 3.1 (1.5-6.1) * 31 632 computer users followed 3 years Daily diaries and triggered physicals Annual Incidence: 33% Trapezius muscle strain 4% Lateral epicondylitis % DeQuervain s disease 9% Flexor tendonitis.9% Carpal tunnel syndrome (N=3) 34 Andersen JH et al. 23 Neck / Shoulder Hand / Arm Logistic Regression: Incident Case of Possible R CTS (N=173) Psychosocial Work Characteristics High demandsd 13(918) 1.3 (.9-1.8) Low control.9 (.7-1.4) Low social support 1.2 (.9-1.8) Time pressure 1. (.7-1.6) 32 Previous history Female Age Non-white 2 th % height Previous computer use Overweight Children < 6 Previous computer use Female Previous history Age Non-white 2 th % height Overweight Children < 6 35 Andersen JH et al. 23 Marcus, et al 22 and Gerr et al, 22 Final Logistic Regression: Incident Case of Possible R CTS (N=173)(adjusting for personal and psychosocial factors) Keyboard K b d Use U (h/wk) Mouse M Use U (h/wk) Postural Risk Factors Hand / Arm (Adjusted Model) Symptoms Hours keying per week Keyboard wrist rest Keyboard away from edge 4 3 Adj OR 2 1-2.5 2.5-5 '5-1 '1- '-2 >2 4 3 2 1 Adj OR - 2.5- '5-2.5 5 1 '1- '- 2 * * '2-25 '25- >3 3 33 Disorders Hours keying per week Keyboard wrist rest Mouse radial deviation Keyboard away from edge 36 David Rempel WOHC 29 6
Discussion narrow wrist support forearm support A wide forearm support board Reduced neck/shoulder pain Reduced R upper extremity pain Prevented incident neck/shoulder disorders in comparison to ergonomics training alone 37 4 Prospective, Controlled, Multi-month Intervention Studies Intervention Number of Workers Reference Ergonomics training 627 Brisson et al. 1999 Split keyboards 8 Tittranonda et al. 1999 Neck school 79 Kamwendo et al. 1999 Work breaks 42 Swanson et al. 2 Vision, arm support Aaras et al. 21 Mouse 67 Aaras et al. 21 Workstation adjustments 124 Ketola et al. 22 Chairs 192 Amick et al. 23 Rest breaks & exercise 268 Van den Heuvel 23 Job stress management 93 Feuerstein et al. 24 Workstation adjustments 376 Gerr et al. 25 Arm support & trackball 182 Rempel et al. 26 Keyboard Tray Problems Monitor too far away Inadequate knee space no effect positive effect 38 No forearm support wrist extension 41 RCT Customer Service Operators (N=182) [Rempel et al. 26] Forearm Support 1 Morency forearm support board 2 Marble Mouse, Logitech Forearm Support 39 Forearms on desk 42 David Rempel WOHC 29 7
Keyboards and Mice? Selecting a mouse Pronation reduction Renaissance (3M) Intellimouse (MS) 3M Mouse Mouseman (Logitech) Contour Evoluent [Aaras 1999, 21; Conlon 28] 43 Evoluent v2 46 Split Keyboards Questions & Comments? [Tittranonda et al. Am J Ind Med 1999] [Moore et al. 23] 44 47 Selecting a mouse 45 David Rempel WOHC 29 8