The effects of exercise training in patients with peripheral vascular disease - a review

Patients with peripheral vascular disease (PVD) suffer from the symptom of intermittent claudication and are therefore intolerant to walking. Exercise training has been shown to be a beneficial treatment for patients with PVD. Therefore studies have aimed to assess the efficacy of exercise training programmes. This review summarises the data on the efficacy of exercise training programmes in patients with PVD. Recommendations are made for the mode, duration, frequency and intensity of exercise training programmes. A systematic review of Medline, Pubmed and Science Direct was done of studies on exercise training and patients with PVD, particularly those using randomised controlled trials. Exercise training improves walking tolerance in patients with PVD. The common mode of training in patients with PVD in the past decade has been walking on a treadmill; however recently an upper-limb cycle ergometry programme proved to be as effective as lower-limb cycle ergometry in improving walking tolerance in patients with PVD. As weight-bearing walking programmes are uncomfortable for patients with PVD, this is an important development in exercise prescription for these patients. Most successful exercise programmes have been 3-6 months in duration for a period of 30 minutes to 1 hour, 2-3 times per week. However, 1 study showed that a shorter period (6 weeks) was of sufficient duration to improve functional capacity in patients with PVD. This is helpful for practitioners as exercise programmes of 3 or 6 months can be daunting for a patient to embark on. Finally, patients should exercise to maximal claudication pain in order to elicit the best training response. South African Journal of Sports Medicine Vol. 18 (4) 2006: pp. 116-12

Peripheral arterial disease and intermittent claudication: Efficacy of short-term upper body strength training, dynamic exercise training, and advice to exercise at home

Objective. To compare the effect of two training programmes and advice to exercise at home on physiological adaptations in patients with peripheral arterial disease (PAD).Design. 30 patients with a typical history of PAD and intermittent claudication were randomised to either an upper body strength training programme (UBST), a dynamic (walking, cycling, circuit) conventional exercise rehabilitation programme (CER), or advice to ‘walk as much as possible at home’ (CONT). Before and after intervention groupsperformed a standard graded treadmill exercise test (GTET) and a 6-minute walk test (SMWT) to determine peak physiological parameters and walking distances. Maximal walking distance (MWD), pain-free walking distance (PFWD), peak oxygen uptake (VO2) , heart rate and perceived pain were measured.Results. MWD on the GTET increased significantly in the CER group compared with the CONT and UBST groups (93.9±79% v. 7.0±19.8% v. 7.3±46%; CER v. UBST v. CONT p=0.003). Similarly, peak VO2 increased with CER compared with the CONT and UBST groups (28.4±20 v. –6.2±15 v. –1.0±21%; CER v. UBST v. CONT p=0.004). During the SMWT the CER and UBST groups improved in PFWD compared with the CONT group (37±47% v. 27±71% v. –30±29%; CER v. UBST v. CONT p=0.03), and perceived pain decreased in the CER group compared with the UBST group (–24±39% v. 27±48%; CER v. UBST p=0.01).Conclusion. CER improves physiological parameters and walking distances more than UBST does. CER is effective within 6 weeks. Verbal encouragement to exercise is an ineffective form of managemen

Factors predicting walking intolerance in patients with peripheral arterial disease(PAD) and intermittent claudication

Objective. To determine which physiological variables conduce to walking intolerance in patients with peripheral arterial disease (PAD). Design. The physiological response to a graded treadmill exercise test (GTT) in patients with PAD was characterised. Setting. Patients were recruited from the Department of Vascular Surgery, Groote Schuur Hospital, Cape Town. Subjects. Thirty-one patients diagnosed with PAD were included in the study. Outcome measures. During a GTT, peak oxygen consumption (VO2peak), peak minute ventilation (VEpeak), peak heart rate and peak venous lactate concentrations were measured and compared with those from a comparison group. Anklebrachial index (ABI) was measured at rest and after exercise. During the GTT, maximum walking distance (MWD) and pain-free walking distance (PFWD) were measured to determine walking tolerance. Results. Peak venous lactate concentrations did not correlate significantly with either PFWD (r=–0.08; p=0.3) or MWD (r=–0.03; p=0.4). Resting ABI did not correlate with either MWD (r=0.09; p=0.64) or PFWD (r=–0.19; p=0.29). Subjects terminated exercise at significantly (

The effects of exercise training in patients with peripheral vascular disease - a review

Patients with peripheral vascular disease (PVD) suffer from the symptom of intermittent claudication and are therefore intolerant to walking. Exercise training has been shown to be a beneficial treatment for patients with PVD. Therefore studies have aimed to assess the efficacy of exercise training programmes. This review summarises the data on the efficacy of exercise training programmes in patients with PVD. Recommendations are made for the mode, duration, frequency and intensity of exercise training programmes. A systematic review of Medline, Pubmed and Science Direct was done of studies on exercise training and patients with PVD, particularly those using randomised controlled trials. Exercise training improves walking tolerance in patients with PVD. The common mode of training in patients with PVD in the past decade has been walking on a treadmill; however recently an upper-limb cycle ergometry programme proved to be as effective as lower-limb cycle ergometry in improving walking tolerance in patients with PVD. As weight-bearing walking programmes are uncomfortable for patients with PVD, this is an important development in exercise prescription for these patients. Most successful exercise programmes have been 3-6 months in duration for a period of 30 minutes to 1 hour, 2-3 times per week. However, 1 study showed that a shorter period (6 weeks) was of sufficient duration to improve functional capacity in patients with PVD. This is helpful for practitioners as exercise programmes of 3 or 6 months can be daunting for a patient to embark on. Finally, patients should exercise to maximal claudication pain in order to elicit the best training response. South African Journal of Sports Medicine Vol. 18 (4) 2006: pp. 116-12

Familiar and unfamiliar face recognition in crested macaques (Macaca nigra).

Many species use facial features to identify conspecifics, which is necessary to navigate a complex social environment. The fundamental mechanisms underlying face processing are starting to be well understood in a variety of primate species. However, most studies focus on a limited subset of species tested with unfamiliar faces. As well as limiting our understanding of how widely distributed across species these skills are, this also limits our understanding of how primates process faces of individuals they know, and whether social factors (e.g. dominance and social bonds) influence how readily they recognize others. In this study, socially housed crested macaques voluntarily participated in a series of computerized matching-to-sample tasks investigating their ability to discriminate (i) unfamiliar individuals and (ii) members of their own social group. The macaques performed above chance on all tasks. Familiar faces were not easier to discriminate than unfamiliar faces. However, the subjects were better at discriminating higher ranking familiar individuals, but not unfamiliar ones. This suggests that our subjects applied their knowledge of their dominance hierarchies to the pictorial representation of their group mates. Faces of high-ranking individuals garner more social attention, and therefore might be more deeply encoded than other individuals. Our results extend the study of face recognition to a novel species, and consequently provide valuable data for future comparative studies

EquiFACS: the Equine Facial Action Coding System

Although previous studies of horses have investigated their facial expressions in specific contexts, e.g. pain, until now there has been no methodology available that documents all the possible facial movements of the horse and provides a way to record all potential facial configurations. This is essential for an objective description of horse facial expressions across a range of contexts that reflect different emotional states. Facial Action Coding Systems (FACS) provide a systematic methodology of identifying and coding facial expressions on the basis of underlying facial musculature and muscle movement. FACS are anatomically based and document all possible facial movements rather than a configuration of movements associated with a particular situation. Consequently, FACS can be applied as a tool for a wide range of research questions. We developed FACS for the domestic horse (Equus caballus) through anatomical investigation of the underlying musculature and subsequent analysis of naturally occurring behaviour captured on high quality video. Discrete facial movements were identified and described in terms of the underlying muscle contractions, in correspondence with previous FACS systems. The reliability of others to be able to learn this system (EquiFACS) and consistently code behavioural sequences was high—and this included people with no previous experience of horses. A wide range of facial movements were identified, including many that are also seen in primates and other domestic animals (dogs and cats). EquiFACS provides a method that can now be used to document the facial movements associated with different social contexts and thus to address questions relevant to understanding social cognition and comparative psychology, as well as informing current veterinary and animal welfare practices

Social use of facial expressions in hylobatids

Non-human primates use various communicative means in interactions with others. While primate gestures are commonly considered to be intentionally and flexibly used signals, facial expressions are often referred to as inflexible, automatic expressions of affective internal states. To explore whether and how non-human primates use facial expressions in specific communicative interactions, we studied five species of small apes (gibbons) by employing a newly established Facial Action Coding System for hylobatid species (GibbonFACS). We found that, despite individuals often being in close proximity to each other, in social (as opposed to non-social contexts) the duration of facial expressions was significantly longer when gibbons were facing another individual compared to non-facing situations. Social contexts included grooming, agonistic interactions and play, whereas non-social contexts included resting and self-grooming. Additionally, gibbons used facial expressions while facing another individual more often in social contexts than non-social contexts where facial expressions were produced regardless of the attentional state of the partner. Also, facial expressions were more likely ‘responded to’ by the partner’s facial expressions when facing another individual than non-facing. Taken together, our results indicate that gibbons use their facial expressions differentially depending on the social context and are able to use them in a directed way in communicative interactions with other conspecifics

Dogs and humans respond to emotionally competent stimuli by producing different facial actions

The commonality of facial expressions of emotion has been studied in different species since Darwin, with most of the research focusing on closely related primate species. However, it is unclear to what extent there exists common facial expression in species more phylogenetically distant, but sharing a need for common interspecific emotional understanding. Here we used the objective, anatomically-based tools, FACS and DogFACS (Facial Action Coding Systems), to quantify and compare human and domestic dog facial expressions in response to emotionally-competent stimuli associated with different categories of emotional arousal. We sought to answer two questions: Firstly, do dogs display specific discriminatory facial movements in response to different categories of emotional stimuli? Secondly, do dogs display similar facial movements to humans when reacting in emotionally comparable contexts? We found that dogs displayed distinctive facial actions depending on the category of stimuli. However, dogs produced different facial movements to humans in comparable states of emotional arousal. These results refute the commonality of emotional expression across mammals, since dogs do not display human-like facial expressions. Given the unique interspecific relationship between dogs and humans, two highly social but evolutionarily distant species sharing a common environment, these findings give new insight into the origin of emotion expression

Paedomorphic facial expressions give dogs a selective advantage

How wolves were first domesticated is unknown. One hypothesis suggests that wolves underwent a process of self-domestication by tolerating human presence and taking advantage of scavenging possibilities. The puppy-like physical and behavioural traits seen in dogs are thought to have evolved later, as a byproduct of selection against aggression. Using speed of selection from rehoming shelters as a proxy for artificial selection, we tested whether paedomorphic features give dogs a selective advantage in their current environment. Dogs who exhibited facial expressions that enhance their neonatal appearance were preferentially selected by humans. Thus, early domestication of wolves may have occurred not only as wolf populations became tamer, but also as they exploited human preferences for paedomorphic characteristics. These findings, therefore, add to our understanding of early dog domestication as a complex co-evolutionary process

Primate modularity and evolution: first anatomical network analysis of primate head and neck musculoskeletal system

Network theory is increasingly being used to study morphological modularity and integration. Anatomical network analysis (AnNA) is a framework for quantitatively characterizing the topological organization of anatomical structures and providing an operational way to compare structural integration and modularity. Here we apply AnNA for the first time to study the macroevolution of the musculoskeletal system of the head and neck in primates and their closest living relatives, paying special attention to the evolution of structures associated with facial and vocal communication. We show that well-defined left and right facial modules are plesiomorphic for primates, while anthropoids consistently have asymmetrical facial modules that include structures of both sides, a change likely related to the ability to display more complex, asymmetrical facial expressions. However, no clear trends in network organization were found regarding the evolution of structures related to speech. Remarkably, the increase in the number of head and neck muscles – and thus of musculoskeletal structures – in human evolution led to a decrease in network density and complexity in humans