A revision of maximal oxygen consumption and exercise capacity at altitude 70 years after the first climb of Mount Everest.

On the 70th anniversary of the first climb of Mount Everest by Edmund Hillary and Tensing Norgay, we discuss the physiological bases of climbing Everest with or without supplementary oxygen. After summarizing the data of the 1953 expedition and the effects of oxygen administration, we analyse the reasons why Reinhold Messner and Peter Habeler succeeded without supplementary oxygen in 1978. The consequences of this climb for physiology are briefly discussed. An overall analysis of maximal oxygen consumption ( V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ ) at altitude follows. In this section, we discuss the reasons for the non-linear fall of V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ at altitude, we support the statement that it is a mirror image of the oxygen equilibrium curve, and we propose an analogue of Hill's model of the oxygen equilibrium curve to analyse the V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ fall. In the following section, we discuss the role of the ventilatory and pulmonary resistances to oxygen flow in limiting V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ , which becomes progressively greater while moving toward higher altitudes. On top of Everest, these resistances provide most of the V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ limitation, and the oxygen equilibrium curve and the respiratory system provide linear responses. This phenomenon is more accentuated in athletes with elevated V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ , due to exercise-induced arterial hypoxaemia. The large differences in V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ that we observe at sea level disappear at altitude. There is no need for a very high V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ at sea level to climb the highest peaks on Earth.

Clinical outcomes of challenging out-of-hospital hypothermia management: A retrospective assessment of DOKEI protocol.

BACKGROUND: Accidental hypothermia (AH) is a major cause of death in mountainous areas globally, and the second highest of mountaineering deaths in Japan, accounting for 37 % in Hokkaido. Managing AH is a significant challenge, particularly when adverse weather complicates the application of recommended rewarming and rapid transfer. To address this, the Hokkaido Police Organization (DOKEI) AH protocol was applied in Hokkaido's remote areas from 2011 to 2022, integrating high-temperature active external rewarming (HT-AER) with on-site sustained treatment. METHODS: This study retrospectively analyzed the rescue reports and hospital records of hypothermia patients treated postprotocol, excluding patients with cold exposure, undetectable vital signs at rescue, and inadequate documentation. Protocol adherence and outcomes-hypothermia stage, cardiocirculatory collapse, survival, and neurological status-were assessed. RESULTS: Among the 60 protocol-treated patients (19-74 years, 85 % male), 14 had stage 2 hypothermia, and 3 had stage 3 hypothermia. HT-AER was applied in 96.7 % of the patients. A total of 98.3 % of patients improved before handover without cardiac arrest (CA) or extracorporeal life support (ECLS). Comparatively, ten preprotocol patients (18-60 years, 70 % male) had two CAs, one fatal and six with no improvement. CONCLUSION: The DOKEI AH protocol demonstrates feasibility in managing stages 1-3 hypothermia, enhancing survival and neurological recovery, and can offer a vital option in challenging AH rescue scenarios.

Measuring critical force in sport climbers: a validation study of the 4 min all-out test on finger flexors.

PURPOSE: The critical force (CF) concept, differentiating steady and non-steady state conditions, extends the critical power paradigm for sport climbing. This study aimed to validate CF for finger flexors derived from the 4 min all-out test as a boundary for the highest sustainable work intensity in sport climbers. METHODS: Twelve participants underwent multiple laboratory visits. Initially, they performed the 4 min intermittent contraction all-out test for CF determination. Subsequent verification visits involved finger-flexor contractions at various intensities, including CF, CF -2 kg, CF -4 kg, and CF -6 kg, lasting for 720 s or until failure, while monitoring muscle-oxygen dynamics of forearm muscles. RESULTS: CF, determined from the mean force of last three contractions, was measured at 20.1 ± 5.7 kg, while the end-force at 16.8 ± 5.2 kg. In the verification trials, the mean time to failure at CF was 440 ± 140 s, with only one participant completing the 720 s task. When the load was continuously lowered (-2 kg, -4 kg, and -6 kg), a greater number of participants (38%, 69%, and 92%, respectively) successfully completed the 720 s task. Changes of muscle-oxygen dynamics showed a high variability and could not clearly distinguish between exhaustive and non-exhaustive trials. CONCLUSIONS: CF, based on the mean force of the last three contractions, failed to reliably predict the highest sustainable work rate. In contrast, determining CF as the end-force of the last three contractions exhibited a stronger link to sustainable work. Caution is advised in interpreting forearm muscle-oxygen dynamics, lacking sensitivity for nuanced metabolic responses during climbing-related tasks.

Simulations of the human heat balance during Mount Everest summit attempts in spring and winter.

The majority of research dealing with the impacts of the Himalayan climate on human physiology focuses on low air temperature, high wind speed, and low air pressure and oxygen content, potentially leading to hypothermia and hypoxia. Only a few studies describe the influence of the weather conditions in the Himalayas on the body's ability to maintain thermal balance. The aim of the present research is to trace the heat exchange between humans and their surroundings during a typical, 6-day summit attempt of Mount Everest in the spring and winter seasons. Additionally, an emergency night outdoors without tent protection is considered. Daily variation of the heat balance components were calculated by the MENEX_HA model using meteorological data collected at automatic weather stations installed during a National Geographic expedition in 2019-2020. The data represent the hourly values of the measured meteorological parameters. The research shows that in spite of extreme environmental conditions in the sub-summit zone of Mount Everest during the spring weather window, it is possible to keep heat equilibrium of the climbers' body. This can be achieved by the use of appropriate clothing and by regulating activity level. In winter, extreme environmental conditions in the sub-summit zone make it impossible to maintain heat equilibrium and lead to hypothermia. The emergency night in the sub-peak zone leads to gradual cooling of the body which in winter can cause severe hypothermia of the climber's body. At altitudes < 7000 m, climbers should consider using clothing that allows variation of insulation and active regulation of their fit around the body.

Myoelectric manifestations of fatigue of the finger flexor muscles and endurance capacity in experienced versus intermediate climbers during suspension tasks.

Climbing is a physically demanding discipline, placing significant loads on the finger flexors. Notwithstanding the documented greater endurance capacity of experienced climbers, the mechanisms explaining these training-induced adaptations remain unknown. We therefore investigate whether two non-competing strategies - muscle adaptation and alternate muscle recruitment - may explain the disparity in endurance capacity in participants with different climbing experience. We analysed high-density surface electromyograms (EMGs) from 38 Advanced and Intermediate climbers, during suspension exercises over three different depths (15, 20, 30 mm) using a half-crimp grip position. From the spatial distribution of changes in MeDian Frequency and Root Mean Square values until failure, we assessed how much and how diffusely the myoelectric manifestations of fatigue took place. Advanced climbers exhibited greater endurance, as evidenced by significantly longer failure time (p < 0.009) and lower changes in MDF values (p < 0.013) for the three grip depths. These changes were confined to a small skin region (nearly 25% of the grid size), centred at variable locations across participants. Moreover, lower MDF changes were significantly associated with longer suspension times. Collectively, our results suggest that muscle adaptation rather than load sharing between and within muscles is more likely to explain the improved endurance in experienced climbers.

Acute mountain sickness on Jade Mountain: Results from the real-world practice (2018-2019).

Acute mountain sickness (AMS) is initiated in response to a hypoxic and hypobaric environment at a high altitude. The precise prevalence of AMS in Jade Mountain climbers remained largely unknown, particularly data obtained from real medical consultations. An overnight stay at the Pai-Yun Lodge (3402 m) is usually required before an ascent of the Jade Mountain. Since 2004, a Pai-Yun Clinic has been established in the Pai-Yun Lodge. The Pai-Yun Clinic provided regular and emergency medical service every weekend. We conducted a retrospective study by using medical records from the Pai-Yun Clinic between 2018 and 2019. A total of 1021 patients were enrolled, with 56.2 % males. Different age groups were 3.2 %, 54.5 %, 37.9 %, and 4.4 % in <20, 20-39, 40-59, and ≥60 years, respectively. There were 582 (57.0 %) patients diagnosed to have AMS (230 [39.5 %] were mild type and 352 [60.5 %] were severe type). The factors associated with AMS development included young age, absence of climbing history (>3000 m) within the last 3 months, first climbing (>3000 m) experience, taking preventive medication, low oxygen saturation, and a high Lake Louise AMS score (LLAMSS). The factors associated with AMS severity included absence of taking preventive medication, low oxygen saturation, and a high LLAMSS. Approximately 15 % of Jade Mountain climbers needed medical service, of which 60 % had AMS. 60 % of patients with AMS must require oxygen supply or medication prescription. Oxygen saturation measure and LLAMSS evaluation are reasonable tools to predict the occurrence and severity of AMS on Jade Mountain.

Towards Automatic Object Detection and Activity Recognition in Indoor Climbing.

Rock climbing has propelled from niche sport to mainstream free-time activity and Olympic sport. Moreover, climbing can be studied as an example of a high-stakes perception-action task. However, understanding what constitutes an expert climber is not simple or straightforward. As a dynamic and high-risk activity, climbing requires a precise interplay between cognition, perception, and precise action execution. While prior research has predominantly focused on the movement aspect of climbing (i.e., skeletal posture and individual limb movements), recent studies have also examined the climber's visual attention and its links to their performance. To associate the climber's attention with their actions, however, has traditionally required frame-by-frame manual coding of the recorded eye-tracking videos. To overcome this challenge and automatically contextualize the analysis of eye movements in indoor climbing, we present deep learning-driven (YOLOv5) hold detection that facilitates automatic grasp recognition. To demonstrate the framework, we examined the expert climber's eye movements and egocentric perspective acquired from eye-tracking glasses (SMI and Tobii Glasses 2). Using the framework, we observed that the expert climber's grasping duration was positively correlated with total fixation duration (r = 0.807) and fixation count (r = 0.864); however, it was negatively correlated with the fixation rate (r = -0.402) and saccade rate (r = -0.344). The findings indicate the moments of cognitive processing and visual search that occurred during decision making and route prospecting. Our work contributes to research on eye-body performance and coordination in high-stakes contexts, and informs the sport science and expands the applications, e.g., in training optimization, injury prevention, and coaching.

Assessing the Impact of Neuromuscular Electrical Stimulation-Based Fingerboard Training versus Conventional Fingerboard Training on Finger Flexor Endurance in Intermediate to Advanced Sports Climbers: A Randomized Controlled Study.

Competitive climbers engage in highly structured training regimens to achieve peak performance levels, with efficient time management as a critical aspect. Neuromuscular electrical stimulation (NMES) training can close the gap between time-efficient conditioning training and achieving optimal prerequisites for peak climbing-specific performances. Therefore, we examined potential neuromuscular adaptations resulting from the NMFES intervention by analyzing the efficacy of twice-weekly NMES-supported fingerboard (hang board) training compared with thrice-weekly conventional fingerboard training over 7 training weeks in enhancing climbing-specific endurance among intermediate to advanced climbers. Participants were randomly divided into the NMES and control groups. Eighteen participants completed the study (14 male, 4 female; mean age: 25.7 ± 5.3 years; mean climbing experience: 6.4 ± 3.4 years). Endurance was assessed by measuring the maximal time athletes could support their body weight (hanging to exhaustion) on a 20 mm-deep ledge at three intervals: pre-, in-between- (after 4 weeks of training), and post-training (after 7 weeks of training). The findings revealed that despite the lower training volume in the NMES group, no significant differences were observed between the NMES and control groups in climbing-specific endurance. Both groups exhibited notable improvements in endurance, particularly after the in-between test. Consequently, a twice-weekly NMES-supported fingerboard training regimen demonstrated non-inferiority to a thrice-weekly conventional training routine. Incorporating NMES into fingerboard workouts could offer time-saving benefits.

Contributions of Griffith Pugh to Success on Mt. Everest and His Impact on the Advancement of Altitude and Environmental Physiology.

Griffith Pugh, MD (1909-1994), was a pioneer in altitude physiology. During World War II, he developed training protocols in Lebanon to improve soldier performance at altitude and in the cold. In 1951 he was chosen to join the British Everest team as a scientist. In preparation, he developed strategies for success on a training expedition on Cho Oyu in 1952. Results from Cho Oyu led to the use of supplemental oxygen at higher flow rates during ascent than used previously (4 L/min vs 2 L/min) and continued use (at a reduced rate of 2 L/min) during descent, enabling increased performance and improved mental acuity. Oxygen was also used during sleep, leading to improved sleep and warmth. Adequate hydration (∼3 L/day) was also stressed, and a more appealing diet led to improved nutrition and condition of the climbers. Improved hygiene practices and acclimatization protocols were also developed. These strategies contributed to the first successful summiting of Mount Everest in 1953. Pugh was then appointed as the lead scientist for a ground-breaking eight-and-a-half-month research expedition where the team was the first to overwinter at high altitude (5800 m) in the Himalayas. This current work summarizes Pugh's scientific contributions as they relate to success on Mount Everest and in inspiring future altitude research by generations of successful researchers.

A Season at the Himalayan Rescue Association Aid Post in Manang.

The Himalayan Rescue Association (HRA) has operated high altitude clinics in Nepal for 50 years, with rising visitor numbers, especially from India, China, and Nepal. New roads have eased access and increased the speed of ascent in some areas. Our aim was to provide a description of the activities, clinical problems, and lecture attendees of the HRA aid post in Manang over one season. We also highlight the evolving challenges of providing healthcare and education in the high Himalayan region. We describe the clinical and educational activities of the HRA aid post in Manang from September 24 to December 1, 2023. Prospective clinical data collection included anonymized patient demographics and diagnoses. Lecture data were taken from the attendee register and by daily manual counts of lecture attendees. We saw 376 patients, 62% of whom were Nepalis. Infectious diseases (42%) and altitude illness (16%) were the most common problems. A total of 846 people from 47 countries attended the daily altitude lectures. Only 5% of attendees were Nepali. Electrical supply interruptions and limitations in medical evacuation options were among the challenges of providing care at a high altitude clinic and preventing altitude illness using educational lectures. Altitude illness remains a common and potentially life-threatening problem, with risks increased by rapid ascent enabled by new road access and by ignorance of risks of altitude among travelers, especially Nepalis. Language barriers in educational outreach call for novel approaches and interventions that will ensure the effectiveness of altitude education.

Severe Hyperthermia in Mountaineering: Coincidence of Heat Stroke and Infection.

Heat illness is a condition that is sometimes seen in those undertaking physical activities. This case report focuses on a female hiker who developed heat stroke during a trek in the Dachstein region of Upper Austria. The patient's presentation was initially unclear and could only be confirmed by the use of a thermometer. This had a significant impact on the medical decision-making process during a complex rescue operation.

Delaying Suspension Syndrome Onset in Aerially Suspended Victims Through Leg Raising.

INTRODUCTION: Suspension syndrome (SS) develops when venous blood pools in extremities of passively suspended individuals, resulting in presyncopal symptoms and potential unconsciousness or death independent of additional injuries. We investigated use of leg raising to delay onset of SS, as it can decrease venous pooling and increase cardiac return and systemic perfusion. METHODS: Participants were suspended in rock climbing harnesses at an indoor climbing wall in a legs-dangling control position or a legs-raised interventional position to compare physiological outcomes between groups. Participants were suspended for a maximum of 45 min. Onset of 2 or more symptoms of SS, such as vertigo, lightheadedness, or nausea, halted suspension immediately. We recorded each participant's heart rate, blood pressure, oxygen saturation, lower leg oxygen saturation, pain rating, and presyncope scores presuspension, midsuspension, and postsuspension, as well as total time suspended. RESULTS: There were 24 participants. There was a significant difference in total time suspended between groups (43.05±6.7 min vs 33.35±9.02 min, p=0.007). There was a significant difference in heart rate between groups overall (p=0.012), and between groups, specifically at the midsuspension time interval (80±11 bpm vs 100±17 bpm, p=0.003). Pain rating was significantly different between groups (p=0.05). Differences in blood pressure, oxygen saturation, lower leg oxygen saturation, and presyncope scores were not significant. CONCLUSION: Leg raising lengthened the time individuals tolerated passive suspension and delayed symptom onset.

The Outcome of Walking Cold Patients with Potential Mild Hypothermia to Safety-A Mountain Rescue Case Series.

INTRODUCTION: Some experts recommend that ambulant hypothermic patients should be rewarmed, fed, and not permitted to exercise for 30 min because of concerns that afterdrop can cause cardiac instability. We investigated the outcome of ambulant hypothermic patients in a case series from mountain rescue teams in Great Britain. METHODS: A questionnaire was used to collect information on a series of adult patients with a clinical diagnosis of mild hypothermia. All patients were alert on the AVPU scale and evacuated by walking from the mountain. The outcome measures were survival or a change in management because of medical deterioration during evacuation. RESULTS: A series of 108 eligible cases were reported over a 5-year period. When rescuers arrived on the scene, 98 (91%) patients were stationary, and 10 (9%) were still mobile. Thirty-eight (39%) of the stationary cases were walked immediately off the mountain without any on-scene delay. In the remaining 60 (61%) stationary cases, the decision was taken to delay evacuation to provide food, drinks, and additional clothing. In 3 cases, the use of heat packs indicated an intention to actively rewarm. In cases where the on-scene time was reported, 27 (79%) were known to be mobile again within 20 min. All patients survived, and no adverse medical events occurred in all 108 cases. CONCLUSIONS: In this study, no adverse events occurred because of immediate mobilization, suggesting that in these cases, there appears to be minimal risk of early activity.

Inappropriate Acetazolamide Use for a Hiker Who Developed Acute Kidney Injury.

Prophylactic use of acetazolamide (ACZ) to prevent acute mountain sickness (AMS) is a common practice among high altitude travelers and mountaineers. With its use comes a possible risk of acute kidney injury (AKI). We present a case in which a 56-year-old male hiker in Grand Canyon National Park developed acute exertional rhabdomyolysis and subsequent AKI while taking prophylactic ACZ to prevent AMS. This medication was prescribed despite the hiker encountering only moderate altitude at Grand Canyon with a planned descent within <24 h. The resulting AKI was determined to be the combined result of acute exertional rhabdomyolysis and dehydration/hypovolemia, with the ACZ, a diuretic, as a contributing factor. Medical providers need to recognize the risks/benefits with ACZ use for AMS prophylaxis and avoid prescribing it to individuals whose altitude exposure and activity fall outside the clinical practice guidelines recommended for use.

Acute Coronary Syndrome at Altitude: Diagnostic Dilemma on Aconcagua Using Point-of-Care Ultrasound.

At the Plaza de Mulas medical tent, located at 4300 m (14,100 ft) along the Normal Route to the 6960 m (22,837 ft) summit of Aconcagua in Argentina, a Korean male in his 50s with no known medical conditions presented with lightheadedness and shortness of breath. He had taken sildenafil and acetazolamide that morning without improvement. Vital signs on arrival were notable for oxygen saturations in the high 60s with basilar crackles on lung auscultation, concerning for high altitude pulmonary edema. The patient was started on oxygen via nasal cannula and given dexamethasone. History was limited secondary to language barriers, but on review of systems the patient noted mild chest pressure. Bedside cardiac echocardiogram was performed, which revealed a septal wall motion abnormality. The patient was therefore given aspirin and clopidogrel and was flown to a lower trailhead, where he was met by local Emergency Medical Services. A 12-lead electrocardiogram revealed an anterior ST-elevation myocardial infarction, and the patient was taken emergently to the catheterization lab in Mendoza and underwent stent placement with a full recovery.

Why do we climb mountains? An exploration of features of behavioural addiction in mountaineering and the association with stress-related psychiatric disorders.

Common knowledge implies that individuals engaging in outdoor sports and especially in regular and extreme mountaineering are exceptionally healthy and hardened. Physical activity in outdoor environments has a positive effect on physical and mental health. However, regular and/or extreme mountaineering might share similarities with behavioural addictions and could thus also have a negative impact on health. In this cross-sectional web-based questionnaire study, we collected data on exercise and mountaineering addiction (Exercise Addiction Inventory; original and adapted version for mountaineering; Exercise Dependence Scale adapted version for mountaineering). Further surveyed parameters included mountaineering habits, Risk-Taking Inventory, Sensation-Seeking/Emotion Regulation/Agency Scale (SEAS), resilience, self-perceived stress, physical activity in metabolic units and mental health. Comparisons were performed between individuals with symptoms of addiction to mountaineering (MA) and individuals without symptoms of addiction to mountaineering or sports in general (CO) using non-parametric analyses. We analysed data from 335 participants, n = 88 thereof with addiction to mountaineering (MA) and n = 247 control participants (CO). The MA group scored significantly higher with regards to self-perceived stress (p < 0.001) and included a significantly higher number of individuals affected by symptoms of depression (p < 0.001), symptoms of anxiety (p < 0.001), symptoms of eating disorders (p < 0.001), alcohol abuse or dependence (p < 0.001), illicit drug abuse (p = 0.050), or current and history of psychiatric disorders (p < 0.001). Individuals with MA showed higher values in all SEAS subscales as well as increased risk-taking (p < 0.001). Regular and extreme mountaineering can display features of a behavioural addiction and is associated with psychiatric disorders. Behavioural addiction in mountaineering is associated with higher levels of sensation-seeking, emotion regulation, and agency, as well as increased risk-taking.

Differences in the effects of a startle stimulus on rate of force development between resistance-trained rock climbers and untrained individuals: Evidence for reticulospinal adaptations?

The aim of the present cross-sectional study was to determine if chronic rock climbing and climbing-specific resistance training (RT) would modify the reticulospinal tract (RST) efficacy. Sixteen healthy, elite level climbers (CL; n = 16, 5 F; 29.8 ± 6.7 years) with 12 ± 7 years of climbing and climbing-specific RT experience and 15 healthy recreationally active participants (CON; n = 15, 4 F; 24.6 ± 5.9 years), volunteered for the study. We quantified RST efficacy by comparing the effects of a startle stimulus over reaction time (Rtime ) and measured rate of force development (RFD) and surface electromyography (sEMG) in representative muscles during powerful hand grip contractions. Both groups performed two Rtime tasks while performing rapid, powerful gripping with the right hand (Task 1) or during 3-s-long maximal voluntary right hand grip contractions in response to an imperative visual signal alone (V), or combined with a auditory-non startle stimulus (A) or/and startling auditory stimulus (S). We also tested the reproducibility of these responses on two separate days in CON. Intersession reliability ranged from 0.34 to 0.96 for all variables. The CL versus CON was 37% stronger (p = 0.003). The S stimulus decreased Rtime and increased RFD and sEMG in both groups during both tasks (all p < 0.001). Rtime was similar between groups in all conditions. However, CL had a greater RFD from 50 to 100 ms compared with CON only after the S stimulus in both tasks (p < 0.05, d = 0.85-0.96). The data tentatively suggest that chronic rock climbing and climbing-specific RT might improve RST efficacy, by increasing RST input to the α-motoneurons.

Mechanisms underlying superior memory of skilled climbers in indoor bouldering.

INTRODUCTION: Bouldering is an Olympic climbing discipline that encompasses short climbing sequences, referred to as boulders, set up on low-height bouldering walls. Memory plays a critical role in bouldering, as it allows climbers to develop climbing strategies, to mentally rehearse climbing movements, and to recall climbing holds of boulders. This study extends previous research on memory in climbing and bouldering with the purpose to elucidate potential mechanisms underlying superior memory abilities of skilled climbers. METHODS: Sixty climbers with intermediate (n = 20), advanced (n = 20), or elite (n = 20) skill levels were tasked to memorise the climbing holds and movements of a boulder, set up on a spray wall and demonstrated by a bouldering expert. RESULTS: Findings revealed a positive relation between the participants' bouldering skills and sport-specific movement knowledge and both, the number of climbing holds and movements they were able to memorise following a two-minute rehearsal period. CONCLUSION: Consistent with previous research, bouldering expertise is positively associated with the ability to memorise domain-specific information. Superior memory abilities among skilled climbers appear to be associated with climbing-specific movement knowledge, coupled with better mental visualisation and increased attentional focus towards functional aspects of boulders.