Hazards in the development of Carpal Tunnel Syndrome

The factors which have been most widely accepted as occupational hazards in the development of CTS include repetitive or sustained flexion of the wrist or contraction of the muscles whose tendons pass through the carpal tunnel, especially when doing forceful work (Zakaria et al. 2002; Palmer

et al. 2007; WSIB, 2008). This type of work has been found to cause inflammation of tendons which can alter the space within the carpal tunnel, and to apply external pressure and thus

compress the median nerve (Zakaria et al. 2002). Vibration and mechanical pressure have also been associated with an increased risk of developing CTS (Zakaria et al. 2002; Palmer et al.2007; WSIB, 2008). Awkward postures at the wrist can increase pressure in the carpal tunnel, or directly compress the median nerve, which may lead to the development of CTS (Zakaria et al.2002).Vibration is oscillatory motion. The extent of oscillatory motion defines the magnitude and the repetition rate of cycles of oscillation determines frequency of vibrations. (page 3)

Figure showing categorization of type of oscillatory motions(page 4).

Human vibration is a multidisciplinary subjects involving discipline from engineering, ergonomics, mathematics, medicine, physics, physiology, psychology and statistics page 3

The motions experienced in an off road vehicle are highly dependent on both the terrain and the manner in which the vehicle is driven. A standard tractor 498-503

Handbook of human vibration by M J griffin ed

Vibration is concerned with oscillatory motion of the body and the forces associated with them. Those bodies which possess mass and elasticity are capable of vibration. So ,most engineering machines and structures experience vibrations and their design generally requires considerations of their oscillatory behaviour

These oscillatory systems can be characterised broadly as linear or nonlinear. There are two general classes of vibration – free and forced vibration. Free vibration takes place when system oscillate under action of forces inherent in the system itself and when external inpressed forces are absent. The system under free vibration will vibrate at one or more of its natural frequencies

Vibration that takes place under excitation of external force is known as forced vibration. When excition is oscillatory system is forced to vibrate at excitation frequency. If frequency of external excitation coincides with natural frequency of system, resonance is produced and as a result large oscillation may results. Theory of vibration and application by willam Thomson page no 5., 4th edition.

Farming is an occupation exposed to whole body vibration

(WBV), mechanical shock, awkward postures and heavy manual

lifting, which are all accepted as low back pain (LBP) risk factors

(Bovenzi et al., 2006; European Union, 2006; Hoy et al., 2005; Lis

et al., 2007; Okunribido et al., 2006b).

Since daily occupational driving is likely to include both WBVs

as well as mechanical shocks it is difficult to distinguish between

the adverse health effects of these factors (Hoy et al., 2005; Waters et al., 2007).

While many studies have examined occupational WBV exposure

(Bovenzi et al., 2006; Hoy et al., 2005; Johanning et al., 2006;

Okunribido et al., 2006a, 2007; Rehn et al., 2005), research into

occupational mechanical shocks and their effects on the human

body have not been as comprehensive. Although the European

Union (2006) has set a daily vibration dose value (VDV) of 9.1 m/

s1.75 as an action limit (AL) and 21.0 m/s1.75 as a maximum

permissible limit (MPL) risk to the health and safety of an operator

is probably greater when such exposure includes transient

mechanical shocks (European Union, 2006; Sandover, 1998;Waters

et al., 2007).

The International Organization for Standardization (ISO) 2631-1

standard (ISO, 1997) advocates use of the vibration dose value (VDV

m/s1.75) as a method for evaluating WBV particularly when the crest

factor exceeds 9.0, indicating the presence of mechanical shock.

However, the ISO 2631-5 (2004) standard has now been introduced

as a guideline for a more direct evaluation of exposure to

mechanical shock which is are thought to cause adverse loading on

the lumbar disc and lumbar vertebral endplates. Adverse health

effects from a combination of both mechanical shock and vibration exposure are thought to include an increased risk of structural and neurological injury to the lumbar spine (Hoy et al., 2005; Bovenziet al., 2006). Disturbance to the nutrition pathways of spinal articular segments, leading to increased degenerative and pathological processes in the lumbar spine are also speculated (Hadjipavlou et al., 2008).

Peripheral nerves are often mechanically damaged in occupational hazards. Acute trauma victims are easily identifiable but gradual development of sign symtoms of peripheral nerves dysfunction can be overlooked in aworker until impaired function affect productivity and safety. Repeated mechanical injury resulting from external forces may cause subacute or chronic syndromes of nerve dysfunction. Compression of nerve within a ligamentous bony canal stretching and subsequent ischemic injury by squeezing of a nerve betwwen muscle edges during repetitive motions are mechanism for injury . changes in design and modification in the design of ahand operated tools or afdaptation in work procedure may prevent further damage and permit recovery.

American journal of occupation medicine 4:661-681 (1983) classical syndromes in occupational medicine .

Peripheral nerve entrapment syndrome and ergonomic factors

Robert g feldmann, MD < rose Goldmann, MD and W Monroe Keysirling , Ph D

It was found that arm

angle in driving posture has a substantial in#uence on the dynamic behavior of tWhen a driver sits on a vehicle seat, s/he chooses a positioning of the seat to operate the

pedals easily. The seat may be moved backwards or forwards according to the stature of a driver in order to operate the pedals without difficulty. The spacing between the steering

wheel and the body then becomes small. The driver has to bend the arm considerably tohe human

body while driving. It is not clear whether the vibration of arms and legs

is an important factor or not for ride comfort. However, when a driver operates the pedals and

the steering wheel, it is important to reduce the vibration from arms and legs in an emergency.

When the vibration of arms and legs increases, the steering wheel and pedals cannot be operated

to prevent an accident. It is therefore desirable to clarify the vibrational characteristics of the

system comprising the human body and the seat, steering wheel and pedals. The transmissibility and the resonance frequency vary with body parts. It is desirable to

reduce the vibration experienced by arms and legs in order to operate the steering wheel and

pedals the arm angle was

observed to have a primary in#uence on the upper arm, the lower arm, the thigh, and the

shin accelerations. It became clear that resonance frequency and peak value for body

parts were di!erent . The standard deviations of both the peak acceleration ratio for upper arm and the

resonance frequency for shin and thigh were large. The following can be said as a result:

there is considerable variability concerning the vibration characteristics of upper arm,

shin and thigh

Journal of Sound and <ibration (2000) 236(1), 1}21

doi:10.1006/jsvi.2000.2862, available online at http://www.idealibrary.com on

RESEARCH ON VIBRATION CHARACTERISTICS

BETWEEN HUMAN BODY AND SEAT, STEERING WHEEL,

AND PEDALS (EFFECTS OF SEAT POSITION ON RIDE

COMFORT)

S. NISHIYAMA AND N. UESUGI

Hiroshima City Industrial ¹echnology Institute, 8-24 Senda-machi 3-Chome, Naka-Ku, Hiroshima City

730-0052, Japan

T. TAKESHIMA AND Y. KANO

Delta Kogyo Company ¸td. 1-14 Shinchi Fuchu-cho, Aki-gun, Hiroshima 735-8501, Japan

AND

H. TOGII

Kuroishi Iron=orks Corporation ¸td. 2-20 Minami Myoujin, Kaita-cho, Aki-gun, Hiroshima 736-0055,

Japan

(Received 28 January 1999, and in ,nal form 10 January 2000)

Excessive exposure to hand-transmitted vibration

can induce disturbances in finger blood flow,

and in neurological and motor functions of the hand

and arm. It has been estimated that 1.7–3.6% of the

workers in the European countries and USA are

exposed to potentially harmful hand-transmitted vibration.

Vascular disorders and joint abnormalities caused

by hand-transmitted vibration are compensated occupational

diseases in 13% of total occupational diseases in

Croatia (Kacian, 1997). These disorders are also

included in an European list of recognized occupational

diseases (ISO 5349-2001). The term ‘‘hand-arm vibration

syndrome’’ (HAVS) is commonly used to refear to

the complex of peripheral vascular, neurological and

musculoskeletal disorders associated with exposure to

hand-transmitted vibration. Even operators on

jobs that seem easy, such as tractor driver, can be

exposed to unexpected vibration. Specially unexpected

are vibration transmitted from the steering wheel to the

driver’s hands. This vibration was already recognized as

a problem (Goglia and Gospodari!c, 2002

During an ordinary working day the driver spends

approximately 6.5 h in effective work. The effective

work consists of two dominant operations during which

the tractor is either idling or at full load.

vibration acceleration level transmitted from the

steering wheel to the driver’s hands will produce finger

blanching in 10% of exposed persons after less than 2

years. Therefore, it is necessary that persons who are

responsible for occupational health and safety take

preventive measures. It is presumed that vibration

hazards are reduced when continuous vibration exposures

over long period are avoided. Therefore, work

schedules should be arranged to include vibration-free

periods.

Applied Ergonomics 34 (2003) 45–49

Hand-transmitted vibration from the steering wheel to drivers of a

small four-wheel drive tractor

V. Gogliaa,*, Z. Gospodari!cb, S. Ko$suti!cb, D. Filipovi!cb

a Faculty of Forestry University of Zagreb, Sveto$simunska 25, 10 000 Zagreb, Croatia

b Faculty of Agronomy University of Zagreb, Sveto$simunska 25, 10 000 Zagreb, Croatia

Received 1 February 2002; accepted 16 September 2002

Each tissue mass has its own natural frequency. Smaller structures tend to resonate at higher frequencies and larger masses tend to resonate at lower frequencies. When the body comes in contact with a mechanical source of vibration the tissues of the body become displaced from their resting position. In the work setting there are basically three types of vibration that are significant to the worker. These include whole body vibration, segmental vibration and resonance. The most common form of whole body vibration is vehicular vibration. In this case vibration enters the body through the buttocks and the feet and to a lesser extent the hands.

All physical systems have their own natural frequency. When tissues of the body are exposed to sources of vibration corresponding to their natural frequency these tissues go into reso . When the muscles of the body are exposed to vibration, they react by exhibiting a protective reflex. The reflex causes the muscles to contract and shorten resulting in an increase in energy consumption. These sustained static muscle contractions result in a rapid fatiguing of the muscle. Fatigued muscles are much more susceptible to injury. The most significant effect is the contraction of the muscles that line the walls of the small blood vessels. These muscles serve to regulate blood flow by constricting and dilating the vessel size. Blood flow is cut off to the affected body part resulting in numbness and tingling. The worker consequently looses sensation and motor control.

11th International Research/Expert Conference

”Trends in the Development of Machinery and Associated Technology”

TMT 2007, Hammamet, Tunisia, 05-09 September, 2007.

CORRELATIONS BETWEEN MECHANICAL VIBRATIONS AND HUMAN HEALTH nance.

Few environmental studies conducted to-date confi rm

that the highest levels of vibration measured at the seats

of agricultural tractors remain mainly within the range of

low frequencies (1-10 Hz), equivalent to the resonance

frequencies for various human body organs [6, 7, 18, 20].

Mechanical vibration with the above-mentioned characteristics

may cause serious disorders in the functioning of

these organs or systems,

The conducted studies of mechanical vibration exerting

a general effect on the whole body occurring on the

seats of agricultural tractors showed that the highest acceleration

values are emitted during agricultural work activities

performed with an elevated operation velocity, along a

hard surface and unequal surfaces.

PRELIMINARY RECOGNITION OF WHOLE BODY VIBRATION RISK

IN PRIVATE FARMERS’ WORKING ENVIRONMENT

Leszek Solecki

Department of Physical Occupational Hazards, Institute of Agricultural Medicine, Lublin, Poland

Solecki L: Preliminary recognition of whole body vibration risk in private farmers’ working

environment. Ann Agric Environ Med 2007, 14, 299-304.

demonstrated vibration-induced disruption of retrograde axoplasmic transport after only two 5-hr long periods of vibration, as well as structural changes to endothelial cells after a single 4-hr exposure to vibration [Curry et al. 2002; Yan et al. 2005].

Curry BD, Bain JLW, Yan J-G, Zhang L-L, Yamaguchi M, Matloub HS, Riley DA [2002]. Vibration injury damages arterial endothelial cells. Muscle Nerve 25(4):527–534.

Yan J-G, Matloub HS, Sanger JR, Zhang L-L, Riley DA [2005]. Vibration-induced disruption of retrograde axoplasmic transport in peripheral nerve. Muscle Nerve 32(4):521–526.

The present study demonstrates the effect on NCV after prolonged vibration and, more importantly, displays the ability of the rat tail nerve to recover from 7-day exposure but not 14-day exposure. Vibration for 14 days causes a decrease in NCV that does not return to normal after a recovery period of 60 days. Vibration for 7 days also causes a significant decrease in NCV, but the injury, although still significant, shows some recovery 30 days post-vibration (group D) and complete recovery 60 days following vibration

VIBRATION-INDUCED NERVE INJURY AND RECOVERY IN A RAT TAIL MODEL

Michael A. Loffredo,1 Dennis Kao,1 Ji-Geng Yan,1 Lin-Ling Zhang,1and Hani S. Matloub1

1Department of Plastic Surgery, Medical College of Wisconsin, Milwaukee, WI

Danny A. Riley,2

2Department of Cell Biology, Neurobiology, and Anatomy,

Proceedings of the Second American C onference on H uman V ibration

Chicago, IL June 4–6, 2008

Driving during the 5 years preceding the onset of symptoms seemed to increase the risk of back pain, whereas earlier exposure did not.

Spine:

January 1992

Original Article: PDF Only

Self-Reported Back Pain in Fork-Lift Truck and Freight-Container Tractor Drivers Exposed to Whole-Body Vibration.

BOSHUIZEN, HENDRIEK C. PhD; BONGERS, PAULIEN M. PhD; HULSHOF, CAREL T. J. MD

Anthropometric evaluation showed abdominal girth and weight to be significantly higher in tractor-driving farmers (P= 0.006 and 0.046, respectively),

Spine:

1 December 1999 - Volume 24 - Issue 23 - p 2506

Clinical Studies

Effect of Whole-Body Vibration on the Low Back: A Study of Tractor-Driving Farmers in North India

Kumar, Adarsh MTech*; Varghese, Mathew MS†; Mohan, Dinesh PhD‡; Mahajan, Puneet PhD‡; Gulati, Praveen MD§; Kale, Shashank MCh∥

The localized decrease in substance P and increased VIP seen following low frequency vibration are compatible with results following peripheral Injury.

Spine:

May 1988

Article: PDF Only

Neuropharmacologic Effects of Vibration on the Dorsal Root Ganglion: An Animal Model.

WEINSTEIN, JAMES DO; POPE, MALCOLM PhD.; SCHMIDT, ROBERT BS; SEROUSSI, RICHARD BS

Based on the measurement results it is quite certain

that the vibration acceleration level transmitted from the

steering wheel to the driver’s hands will produce finger

blanching in 10% of exposed persons after less than 2

years

Applied Ergonomics 34 (2003) 45–49

Hand-transmitted vibration from the steering wheel to drivers of a

small four-wheel drive tractor

V. Gogliaa,*, Z. Gospodari!cb, S. Ko$suti!cb, D. Filipovi!cb

Few environmental studies conducted to-date confi rm

that the highest levels of vibration measured at the seats

of agricultural tractors remain mainly within the range of

low frequencies (1-10 Hz), equivalent to the resonance

frequencies for various human body organs [6, 7, 18, 20]

Solecki L: Whole body vibration in agricultural vehicles – a significant

health risk factor. In: Solecki L (Ed): Physical Hazards in Agriculture,

57-65. Institute of Agricultural Medicine, Lublin 1999 (in Polish).

Solecki L, Choina P, Wasilkowski J, Michalczuk A: Recognition of

risk due to the whole body mechanical vibration in private farmers’ work

environment. [Report from Project No. 2.17/05] for 2005-2006. Institute

of Agricultural Medicine, Lublin 2006 (in Polish)..

Fairley TE: Predicting the discomfort caused by tractor vibration.

Ergonomics 1995, 38, 2091-2106.

Futatsuka M, Maeda S, Inaoka T, Nagano M, Shono M, Miyakita

T: Whole-body vibration and health effects in the agricultural machinery

drivers. Ind Health 1998, 36, 127-132.

Goglia V, Gospodaric Z, Filipovic

Vibration

occurring on the handles of these machines cause

vascular, neurological and musculoskeletal changes, resulting

in vibration-induced white fi nger syndrome

Goglia V, Gospodaric Z, Filipovic D, Djukic I: Infl uence on operator’s

health of hand-transmitted vibrations from handles of a single-axle

tractor. Ann Agric Environ Med 2006, 13, 33-38.

Health effects

to the lower extremity (“white-feet”) related to standing

on vibrating surfaces have been reported in i.e. mining

Eger T, Thompson A, Leduc M et al. Vibration induced white-feet:

overview and field study of vibration exposure and reported symptoms

in workers. Work 2014; 47: 101–110.

Anthropometric evaluation showed abdominal girth and weight to be significantly higher in tractor-driving farmers

Spine:

1 December 1999 - Volume 24 - Issue 23 - p 2506

Clinical Studies

Effect of Whole-Body Vibration on the Low Back: A Study of Tractor-Driving Farmers in North India

Kumar, Adarsh MTech*; Varghese, Mathew MS†; Mohan, Dinesh PhD‡; Mahajan, Puneet PhD‡; Gulati, Praveen MD§; Kale, Shashank MCh∥

decreased nerve conduction velocity, sober ... dose populations such as truck drivers, bus drivers,

heavy equipment operators, foundry workers, farm tractor drivers

The Effects of Whole-body Vibration on Health

HE von Gierke – 1979

Exposure to FTV can lead to vibration white feet/toes resulting in blanching of the toes, and tingling and numbness in the feet and toes. Operators exposed to FootTransmitted Vibration at 40 Hz appear to be at greater risk of experiencing vibration induced injury.

Tammy Eger^{1, 2}, Aaron Thompson^{3, 4}, Mallorie Leduc¹, Kristine Krajnak⁵, Katie Goggins¹, Alison Godwin^{1, 2}, Ron House^{3, 4} Volume 47, Number 1 / 2014 Vibration induced white-feet: Overview and field study of vibration exposure and reported symptoms in workers

JournalWork: A Journal of Prevention, Assessment and Rehabilitation