Identification of feigned maximal shoulder external rotation effort.
OBJECTIVE
To examine the efficiency of the difference between the isokinetic eccentric to concentric strength ratios at high and low velocities (DEC) for identifying feigned maximal shoulder external rotation effort.


BACKGROUND
Previous studies have indicated that the DEC is a powerful identifier of feigned maximal effort. However comparison of maximal versus feigned maximal shoulder external rotation effort has not been undertaken. Due to the high prevalence of rotational shoulder disorders and their chronic ramifications in terms of occupational disability such a study is of specific interest.


METHODS
Maximal and feigned maximal shoulder external rotation isokinetic efforts were compared.


METHODS
Functional evaluation unit at an occupational rehabilitation centre.


METHODS
Seventeen healthy male volunteers aged between 20 and 40 years old.


METHODS
Concentric and eccentric isokinetic tests at 30 degrees /s and 120 degrees /s in maximal and feigned maximal experimental conditions. DEC was calculated by subtracting the 30 degrees /s eccentric/concentric peak torque ratios from the 120 degrees /s ones for both experimental conditions.


RESULTS
A case-by-case analysis revealed that the DEC scores derived from the feigned effort were significantly greater than their maximal counterparts in all cases, leading to a cut-off value (0.81) which could distinguish between maximal and feigned performances.


CONCLUSIONS
The findings indicate that the DEC is highly effective in identifying feigned shoulder external rotation effort in normal subjects.
Chaler
Joaquim
J
Department of Physical Medicine and Rehabilitation, Mútua Egara, Terrassa, Spain. 27522jcv@comb.es
Dvir
Zeevi
Z
Díaz
Urko
U
Quintana
Salvador
S
Abril
Angels
A
Unyó
Carme
C
Garreta
Roser
R
D000328:Adult; D008192:Deception; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology; D053581:Muscle Strength Dynamometer; D018908:Muscle Weakness / Q000175:diagnosis*; D010808:Physical Examination / Q000379:methods*; D012399:Rotation; D012785:Shoulder Joint / Q000502:physiology*; D019415:Torque