Combined influence of expertise and fatigue on riding strategy and horse­rider coupling during the time course of endurance races.

REASONS FOR PERFORMING STUDY: The relationship between the biomechanical horse­rider interaction and endurance race performance requires further investigation. OBJECTIVES: To characterise, both quantitatively and qualitatively, elite and advanced horse­rider dyads on the basis of the biomechanical horse­rider interaction during endurance races. STUDY DESIGN: Five elite and 5 advanced horse­rider dyads were recorded during CEI*/CEI** endurance races using 2 synchronised triaxial accelerometers each placed close to horse and rider centres of mass. METHODS: For each horse­rider dyad, analyses focused on the vertical displacements of horse and rider per stride. This allowed quantification of the proportional use of each gait and riding technique per loop. The quality of the biomechanical horse­rider interaction was examined through the relative phases (RP) of their respective vertical displacement minima. Instantaneous speed and rider heart rates were recorded using a global positioning system device/heart rate monitor. RESULTS: All dyads predominantly used 2 riding techniques per gait. The 2-point trot proportion was limited in both groups (11%). Throughout the race, the advanced horse­rider dyads showed a global stability in speed, in the proportion of 4 combinations of gait and riding techniques and in mean RP. However, the elite horse­rider dyads initially had higher mean RP values (P<0.01), and from mid-race to the end an increasing proportion of sitting canter, with associated increases in racing speed (P<0.001) and in mean heart rate (P<0.01). Intradyad RP variability in 2-point canter increased in both groups (P<0.01). CONCLUSIONS: Accelerometers are a valuable tool to follow the quantitative and qualitative trends of the biomechanical horse­rider interaction during international endurance races. The overall results emphasise the influence of the level of expertise on the adopted gait and riding techniques, thus influencing the racing speed. It remains to be established whether fatigue and/or strategy underlie our observations.

[Apotemnophilia as a contemporary frame for psychological suffering]. / Apotemnophilie: une mise en forme contemporaine de la souffrance psychique?

UNLABELLED: The word <> was created in 1977. It was first used to describe an extreme paraphilia concerning both the search for amputees as sexual partners, and the fantasies and wishes to be amputated linked to a sexual arousal. CLINICAL FINDINGS: More recently, the number of self-demand amputations appears to have raised. Some amputations of healthy legs have even been performed in hospital settings, raising important ethical issues. A new category of trouble has been described: the Body Integrity Identity Disorder (BIID). Criterias for its diagnosis have been developed and submitted to DSM V task force. According to clinicians who support the existence of BIID, this disorder is not a paraphilia, don't overlap with other psychiatric disorders and could be in some ways compared to transexualism. The patient's health would therefore require the amputation of healthy limbs in order to <> themselves and to help them to become <> according to their <>. Still according to those clinicians, psychiatric symptoms would be either a consequence of the shame resulting from this condition, or a consequence of the doctor's refusal to perform these amputations. An ever growing <> litterature on the web support this opinion, but the scientific litterature is still very scarce. LITERATURE FINDINGS: In this paper, we analyse available scientific datas. This review does not support the existence of BIID as a discrete nor a specific condition. CASE-REPORT: In a second part of this paper, we describe the case of a young woman who started asking for above-the-knee leg amputation after a minor knee trauma, while complaining for pain and leg rigidity. Her medical state worsened, probably because of repeated self-inflicted lesions and food restriction, leading to a severe undernutrition and life-threatening hypokaliemia. After some time, her medical state required amputation. This surgery did not resolve her psychological suffering. She never talked about amputation as a way to achieve herself. She did not meet the criterias for BIID. We consider her trouble as an association of a factitious disorder with a borderline personality disorder. DISCUSSION: In the last part of this paper, we discuss the <> scientific litterature about apotemnophilia and BIID. We support the idea that BIID can be considered as a culture-bound syndrome, a contemporary frame for psychological suffering. We think that BIID does not have neither intrinsic nor unequivocal psychopathological meaning. It is a <> (Elliott), a common pathway for the expression of very different kinds of psychological suffering. CONCLUSION: Apotemnophilia and BIID are raising important ethical and practical issues for psychiatrists: their opinion will probably be requested by patients and surgical teams having to deal with patient asking for healthy limbs amputation.