The Effect of Angled Hammers on Wrist Motion

This research investigated the range of wrist motion characteristics associated with the ergonomic principle of “bending the tool and not the wrist” as applied to the hammer. It is thought that bending the tool reduces wrist motion, which has been shown in the literature to be a risk factor in hand/wrist disorders, such as carpal tunnel syndrome, tenosynovitis, etc. Bent hammer handles resulted in a tradeoff in beginning and ending positions of the wrist throughout a hammering stroke. Bending the hammer handle to 20 or 40 deg. resulted in significantly less ulnar deviation than a straight hammer, but also increased radial deviation. Overall, the angular deviation from neutral position in the radial/ulnar plane was significantly less for the 20 and 40 deg. hammers than for the straight hammer. This research suggests that angled hammer handles in the range of 20 to 40 degrees could possibly decrease the incidence of hand/wrist disorders caused by the use of hammers.

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Effects of Handle Angle and Work Orientation on Hammering: I. Wrist Motion and Hammering Performance

Human Factors The Journal of the Human Factors and Ergonomics Society ◽

10.1177/001872088903100404 ◽

1989 ◽

Vol 31 (4) ◽

pp. 397-411 ◽

Cited By ~ 32

Author(s):

Richard W. Schoenmarklin ◽

William S. Marras

Keyword(s):

Risk Factor ◽

Ulnar Deviation ◽

Trade Off ◽

Wrist Motion ◽

Starting Position ◽

Impact Position ◽

Novice Users ◽

Tunnel Syndrome ◽

Motion Characteristics ◽

The Impact

This research investigated the range of wrist motion characteristics associated with the ergonomic principle of “bending the tool and not the wrist” as applied to the hammer. It is thought that bending the tool reduces angular wrist motion, which has been shown in the literature to be a risk factor in hand/wrist disorders such as carpal tunnel syndrome and tenosynovitis. Hammer handles angled at 0 (straight), 20, and 40 deg were investigated in this study. For novices, hammer handles bent at 20 and 40 deg resulted in less total ulnar deviation than straight hammers. However, there was a trade-off in beginning and ending positions of the wrist in that the angled hammers reduced ulnar deviation at the impact position but increased radial deviation at the starting position of a hammer stroke. Handle angle did not significantly affect hammering performance. Wrist motion was affected minimally by hammering orientation, but hammering performance was significantly worse in the wall orientation compared with the bench orientation. This research suggests that for novice users, hammers with handles bent in the range of 20 to 40 deg could possibly decrease the incidence of hand/wrist disorders caused by hammering.

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Arthritis as a risk factor for carpal tunnel syndrome: a meta-analysis

Scandinavian Journal of Rheumatology ◽

10.3109/03009742.2015.1114141 ◽

2016 ◽

Vol 45 (5) ◽

pp. 339-346 ◽

Cited By ~ 22

Author(s):

R Shiri

Keyword(s):

Risk Factor ◽

Carpal Tunnel Syndrome ◽

Carpal Tunnel ◽

Meta Analysis ◽

Tunnel Syndrome

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Smoking as risk factor for carpal tunnel syndrome: A birth cohort study

Muscle & Nerve ◽

10.1002/mus.26627 ◽

2019 ◽

Vol 60 (3) ◽

pp. 299-304

Author(s):

Sina Hulkkonen ◽

Juha Auvinen ◽

Jouko Miettunen ◽

Jaro Karppinen ◽

Jorma Ryhänen

Keyword(s):

Risk Factor ◽

Cohort Study ◽

Carpal Tunnel Syndrome ◽

Birth Cohort ◽

Carpal Tunnel ◽

Birth Cohort Study ◽

Tunnel Syndrome

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Elevated Tissue Polypeptide Antigen as a Risk Factor for Carpal Tunnel Syndrome in Haemodialyzed Patients

Nephron ◽

10.1159/000185133 ◽

1988 ◽

Vol 50 (1) ◽

pp. 83-84 ◽

Cited By ~ 3

Author(s):

Gerd Walz ◽

Ulrich Kunzendorf ◽

Anke Schwarz ◽

Renate Bauer ◽

Frieder Keller ◽

...

Keyword(s):

Risk Factor ◽

Carpal Tunnel Syndrome ◽

Carpal Tunnel ◽

Tissue Polypeptide Antigen ◽

Tunnel Syndrome

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Correlation of Segmental Carpal Tunnel Pressures with Changes in Hand and Wrist Positions in Patients with Carpal Tunnel Syndrome and Controls

Journal of Hand Surgery (European Volume) ◽

10.1016/s0266-7681(98)80009-0 ◽

1998 ◽

Vol 23 (5) ◽

pp. 598-602 ◽

Cited By ~ 45

Author(s):

R. LUCHETTI ◽

R. SCHOENHUBER ◽

P. NATHAN

Keyword(s):

Carpal Tunnel Syndrome ◽

Carpal Tunnel ◽

Nerve Conduction ◽

Nerve Conduction Studies ◽

Distal Margin ◽

Neutral Position ◽

Threshold Levels ◽

Tunnel Syndrome ◽

And Control

We investigated pressures at 1 cm intervals along the carpal tunnel in 39 patients with carpal tunnel syndrome (CTS) and 12 controls. Pressures were measured for relaxed and gripping hand positions in combination with neutral, extended, and flexed wrist positions. Patient pressures exceeded control pressures, were below the previously reported 30 mmHg threshold for four of five locations in the relaxed neutral position and were typically greater in extension than in flexion. In the neutral position, both patient and control pressures were slightly above threshold levels just distal to the tunnel. Maximum intratunnel pressures were generally found in the central part of the tunnel and minimum pressures in the distal tunnel. Gripping hand pressures in the tunnel were lowest with the wrist flexed. In both controls and CTS patients, only in the neutral wrist and relaxed hand positions were pressures highest at the point where nerve conduction studies have indicated the nerve is most likely to be compromised (in the midpalm just distal to the distal margin of the carpal tunnel).

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Student Section

Canadian Journal of Occupational Therapy ◽

10.1177/000841747704400312 ◽

1977 ◽

Vol 44 (3) ◽

pp. 144-144

Author(s):

Rosemary Weiss

Keyword(s):

Carpal Tunnel Syndrome ◽

Median Nerve ◽

Carpal Tunnel ◽

Clinical Picture ◽

Neutral Position ◽

Wrist Movement ◽

Tunnel Syndrome ◽

Median Artery

A closer look at splinting for carpal tunnel syndrome (CTS) is necessary, since it is suggested that there are two types of CTS. 1) neural CTS, with a typical clinical picture of injury of the median nerve and, 2) vascular CTS where the early dominant symptoms are ischemic due to compression of a) a persisting median artery and, b) the radial and ulnar arteries Preventing wrist movement and excessive gripping during the day, alleviates compression of the radial, ulnar and possibly persisting median artery, and the median nerve. Thus, a release phenomenon does not occur at night. It is suggested that the wrist be splinted in a functional splint during the day, and a resting splint during the night, supporting the wrist in both cases, in a neutral position.

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