I think it will be tastefully okay for me to reproduce a cropped colourised image of Igor's hands as example. He was right-sided and his hand was found sticking above the snow. There are unbroken contusions, erythema there, but when people fight they typically break the skin of the knuckles and there's some bleeding. Yet not a single knuckle is affected and his leading knuckle isn't as bad as the others. Only one hand is affected, yet it's commonly suggested he'd been fighting with both hands, as if for his life.
How would they injure their knuckles though? Any theory needs to explain that, imo.
I expect it's common for people who aren't experienced fighters to only throw punches with their dominant hand. Yuri's knuckles on his right hand were injured, was he right handed too? Rustem had bruised knuckles on both hands, Zinaida had a large bruise from a baton shaped object, Igor's ankle injuries suggest he'd been tied up, several of them had injuries to their faces consistent with being punched. I'm a bit surprised Zinaida had injuries on her knuckles though, without meaning to be sexist I doubt a girl could punch that hard.
None of the victims found near the den had injured knuckles, if anything I'd expect them to have more injured hands from digging out the den, if there wasn't a fight.
How they came by their injuries is largely irrelevant. What matters most is why they pitched where they did and why they left, and without taking what they needed to survive when facing near certain death otherwise, and, with the risk of explosives in forests, I'm suggesting we now have a logical starting point for why they pitched up there.
It's only to be expected that when 9 people, instead of being able to huddle together to conserve their energy and get through the night in freezing temperatures and high winds, are instead forced to expend all their energy until completely exhausted, that they will collect a series of injuries along the way as opposed to being found frozen to death without a mark on them.
The nature of the injuries tends to throw up wild interpretations, which the pathologist did not suggest or make part of his conclusion. For example mention of a deformed neck is often taken to mean broken. Deformed is not the same as fracture. It could, for example, be due to a history of malnutrition, or a previous problem with vertebrae and healing. Aleksander's younger ID photo's appear to show a potential problem with his jaw too.
People also suggest a loose hyoid bone must indicate foul play, but every bone is held in position by tissues, the skeleton is not one contiguous array of self-supporting framework, so when the connective tissues, tendons, muscles, all attaching to bone has rotted away, as happened with Lyuda's oral cavity, the lingual bone will have little support left. The pathologist does not suggest this indicated murder, he does not even mention it in his conclusions, and he does not state it was fractured, as with the case of Jeffrey Epstein.
Typical resus fractures are focused on exactly the same ribs as two hikers had broken. The problem is a pathologist only sees the ones where open fractures penetrate the heart or lungs, whereas an orthopaedic will see thousands more examples of people who survive with the same injuries, and out of that be aware of a greater variety of ways they come by such injuries.
Igor using his legs to grip trees during climbing and reaching to cut branches would cause marks around his ankles. Elderly people who are bedridden get the same from crossing their ankles in bed. Had he been restrained by his ankles then surely his wrists would need restraint too and show similar marks.
Igor's knuckles could either be from a brief skirmish, perhaps with Yuri K, or a consequence of that hand being most exposed to the elements for several weeks above snow. There are medical conditions which can affect the knuckles without breaking the skin, particularly herpes-related, which can flare up when someone's immune system is under stress in a cold environment, in the same way holiday skiiers go down with cold sores. I myself get flare-ups of a condition called erythema multiforme which affects my knuckles, making it appear I've been in a fight, though both hands are affected.
The other two were found face/side down and appear to have been crawling. I can't see Rustem fighting like a UFC pro anymore than I can Zina to be honest. They may have adopted a technique of using their fists, in order to save their fingers from frostbite, and drawn their hands either to the side, or down their chest to their navel, while pushing up the snow with their feet, where the lower half of their body takes the greatest weight due to the slope, because that is how people sometimes crawl.