Not quite Heliskiing here – the helicopter just happened to pass when the filming started. The snow was layered and crusted by the sun but still soft enough for the skis to pivot. The skiing demonstrated both here and in the video clip is a “two footed pivot” with both skis being used as a single pivoting platform. Everything is being “pulled inwards” – despite appearances nothing is being pushed to the outside. 
When using a pivot the skis are kept below the skier on the mountain and the unweighting from the end of the previous turn is exploited – instead of using pressure and the inside edge or base of the outside ski to drive the turn it’s the lightness and active (inwards) swing of both skis while remaining on their uphill edges that is being exploited. This only works when snow remains soft enough for the skis to overcome the snow or when the skier is airborne! 
Running Evolution
For a long time I’ve worked on techniques and fundamentals of movement that cross over from one sport to another. Running is one of the key activities where this cross over plays a major part. Today it appears that I’ve finally cracked a problem that has plagued me for several years particularly with respect to “barefoot running – or in this case in minimalist trail running shoes with no significant cushioning. The spine and hip actions in common with the two activities are clearly documented here: http://skiinstruction.blogspot.fr/p/chiskiing.html so I won’t go into any of that. The issue that has constantly troubled me is the problem of stress on the calf muscles. Zero drop (no difference in height between forefoot and heel) shoes with significant cushioning actually stops the problem and all the calf muscle trauma and pains – but it appears there has actually been a very subtle proprioception issue behind the problem that cushioning was only hiding. Although I’ve been trying to mainly foot strike just in front of the heel (midfoot really), it seems that there has been a small amount of dropping the forefoot to the ground first. This slightly early contact of the forefoot with the ground – that I’ve not been aware of – causes the calf muscle to contract so that is is not relaxed enough and this is probably immediately followed by a sharp eccentric contraction – (muscle extending while under contraction). It seems that years of running and walking with artificially raised heels has probably created a tendency to drop the forefoot lower so as to compensate for the heel. When the artificial heel is removed then the foot still functions this way – leading to a confused proprioception. To help to address this issue I ran to a cadence of 90 – which is 180 steps per minute. The idea was to shorten the stride and focus on holding the forefoot up and never reaching ahead – while running on minimalist trail shoes. The high “optimal” cadence encourages this shortened “many steps” stride. To help to maintain the correct cadence I used psytrance music at 90 bpm downloaded free from the internet http://www.ektoplazm.com/ – just look for 90 bpm tracks and make a compilation. Interestingly I ran the 10k a few minutes slower than my previous run due to not being used to the short stride and high cadence – in rain, slush, mud and on tarmac – but without the feeling of stress on the calves that even cushioned shoes would have. Normally with minimalist trail shoes – which are quite hard underfoot to give good ground feel – I’d be feeling significant pains and muscle fatigue at around 7 km in the absence of a great deal of conditioning.