Strength and Leverage

[brobear]

The California Grizzly - bear in mind - from the collections of the Bancroft library:

This animal - the biggest and fiercest of the genus - inhabits the mountainous parts of the Missouri region, the forested banks of the Yellowstone River and of the Little Missouri, and the great Rocky Mountain range. It is much bigger, stronger, and faster than the biggest Brown Bear. It often weighs from 800 to 900 pounds. Its muscular strength is so great that it can easily kill the biggest bison. Its fur is used for making muffs and shawl trim, and its pelt sells for twenty to fifty dollars.

[brobear]

wildfact.com/forum/attachment.php?aid=207

Here is a portion of that site information: quote - Muscle mass is similar between the prime bear and the six­year subadult bear, with average muscle mass percentage levels differing at a rate of 1.38±0.24%. The muscle mass of the three year old bear was relatively low due to its low total weight, and the muscle mass of the oldest specimen concurred with the relatively high amounts of Ib fibres: the densest muscle fibres discovered in mammalian and reptilian bodies so far. Thus, the expected muscle weight of the post­prime aged bear should exceed that of the prime bear, even though the muscle volume is slightly higher in the prime aged bear. The maximum percentage of Ib fibres in the post­prime bear slightly, by 0.9%, exceeds the maximum percentage of IIa/x and IIb fibres in the prime bear, thus producing this result. Muscle density is far­exceeding within the oldest specimen also due to the over­accumulation of dense Ib fibers. In conclusion, no significant evidence provided any leads towards increased muscle strength deterioration or muscle mass deterioration in post­prime brown bears, yet evidence had been found of increased muscle volume deterioration in post­prime brown bears as. The brown bears who were experimented on were shortly released back into their respective locations within Yellowstone National Park after the study commenced. These findings suggest that brown bears, if not all bear species as a whole, are able to retain their muscle mass and maximum muscle strength well past their prime years, unlike most other animals.

[brobear]

Posted by Polar - In other words, post-prime brown bears (most likely all bears) can continue to gain muscle mass and maximum force without much muscle volume due to them being able to gain dense slow-twitch Ib fibers much easier, again, due to higher ERL levels.

Prime brown bears are able to gain muscle volume, but not as a fast rate as muscle mass or maximum force, that's why they look so huge and bulk at lower weights. At equal sizes/dimensions, the post-prime brown bear would most likely be much MUCH heavier than the prime brown bear due to, again, denser Ib fibres.

Fast-twitch fibers (IIa/x and IIb fibers) are larger in volume at the same mass than slow-twitch fibers (Ia and Ib fibers), and they produce the most change in force within the shortest time, not the absolute most force. IIa fibers contract forces very fast within the first second of activation, and IIb fibers, being even larger in volume within the same mass as IIa fibers, contact the same forces at an average speed 40% faster than IIa fibers.

Slow-twitch fibers actually have two functions: one for endurance/stamina, and one for a gradual contraction of brute force. Ia fibers are the former and Ib fibers are the latter. Ia fibers contract at maximum force depending on how many of those fibers the person has (hence, why a great marathon runner's muscles ache after a 2-hour marathon, and why a sprinter's muscles ache after about 40 seconds, if accounting for the same cardiovascular/respiratory endurance levels and weight: they each have an individual percentage of these Ia fibers.) Usually, the maximum force of Ia endurance-type fibers is 20% of the force displayed in either IIa/x or IIb fibers.

[brobear]

Posted by Polar - On the other hand, Ib brute strength-type fibers, at the same mass as either of IIa/x or IIb fibers, produce approximately 80% more force than the two fibers at maximum contraction, albeit at a much much slower rate, at approx. 13 (have to look back at the article: I found new research on muscle fibers about two years ago, but sadly didn't save it under my Google Drive) seconds for max force.

People think that greater fast-twitch fiber levels (bigger muscles) will lead to an increased maximum amount of force output. No, it will only lead to an increased amount of force output within the shortest amount of time. That's how the "fast-twitch fibers are stronger than slow-twitch fibers" myth originated, because of the confusion between power (maximum force output within shortest amount of time) and strength (maximum force output overall at any time.) Really, at the same volume, a muscle composed of Ib fibers will be humongously stronger at maximum contraction than a muscle composed of either IIa/x or IIb fibers, however, the IIa/x muscle will contract more force than the Ib muscle for the first one second, and IIb muscle will contract more force than the IIa/x muscle before one second and much more force than the Ib muscle during that same time period. It's all about the rate/time of contraction.

I will post more on real-life uses of fast-twitch IIa/x and IIb fibers and slow-twitch Ib fibers later.

[brobear]

THE BEAR - History of a Fallen King - Michel Pastoureau - 2007.
The brown bear appears first of all as a powerful and massive creature that could reach a ( bipedal ) height of eight or nine feet and a weight of 600, 800, or even 1,000 pounds. Those are, of course, record figures, at least in Europe, but it is likely that ancient and medieval bears were heavier than their present-day descendants. The bear is fattest in late autumn, when it begins hibernation. Its heavy look and clumsy appearance are accentuated by a short, thick neck of extraordinary strength and a very broad chest. Neck and chest contrast with a relatively small head and modest hindquarters. The animal's primary strength is located in the muscles of the neck, shoulders, arms, and chest. It resembles a stocky wrestler with a disproportionately large upper body. This is confirmed by anatomic analysis of its musculature, which reveals very powerful brachial, dorsal, and pectoral muscles. They are what enable the bear to carry or haul loads heavier than itself, to move gigantic blocks of stone, to break huge tree trunks, to kill a man or a large animal - cattle or wild game - with a single blow of a paw.   
 
            

[brobear]

( in my own words )... The grizzly is very likely the strongest living animal of his size. The measuring of animal strength is not an exact science. The strength of a silver-back gorilla has never been measured, but I'm sure that he has enormous physical strength. However, The grizzly is even stronger. The grizzly pictured appears to have an over-sized head. Actually, his head is normal in size. It is his massive neck that gives this appearance.
 

[brobear]

mytakeontv.wordpress.com/2009/05/16/exploring-grizzly-bears-with-casey-anderson/

What is something that you learned in spending the year with Grizzlies that has affected your daily life going forward?
Insight from Brutus: if it is physically possible, then it is done. If not, it isn’t. After weighing a boulder in at one ton, we used a tractor to lift it to place a piece of salmon under it. Soon after, Brutus caught the scent of the salmon and walked to the boulder. In one swift move, he pushed the boulder to the side and happily devoured the salmon. It dawned on me as I stood next to my friend: he doesn’t worry much; he is not handicapped by his mind. If his body isn’t capable of doing it, then that is his only limitation. He does not sit there and contemplate, or make excuses; he just does all he can. Then goes and takes a nap in the sunshine. How great would it be if we could all live that way?

[brobear]

Great Bear Almanac by Gary Brown.
Shoulder Hump ( Brown Bear ).
Brown bears have a shoulder hump between their shoulders that is covered with long hair and is normally a reliable means of species identification. The long hair often accentuates the hump when the "hackles" are raised. This distinguishing feature is a distinctive mass of muscle that provides the brown bears with their exceptional digging ability and the powerful striking force of the forepaws.

[brobear]

jeb.biologists.org/content/jexbio/215/12/2081.full.pdf
SUMMARY
Hibernating bears retain most of their skeletal muscle strength despite drastically reduced weight-bearing activity. Regular neural
activation of muscles is a potential mechanism by which muscle atrophy could be limited. However, both mechanical loading and
neural activity are usually necessary to maintain muscle size. An alternative mechanism is that the signaling pathways related to
the regulation of muscle size could be altered so that neither mechanical nor neural inputs are needed for retaining strength. More
specifically, we hypothesized that muscles in hibernating bears are resistant to a severe reduction in neural activation. To test this
hypothesis, we unilaterally transected the common peroneal nerve, which innervates ankle flexor muscles, in hibernating and
summer-active brown bears (Ursus arctos). In hibernating bears, the long digital extensor (LDE) and cranial tibial (CT)
musculotendon masses on the denervated side decreased after 11weeks post-surgery by 18±11 and 25±10%, respectively,
compared with those in the intact side. In contrast, decreases in musculotendon masses of summer-active bears after denervation
were 61±4 and 58±5% in the LDE and CT, respectively, and significantly different from those of hibernating bears. The decrease
due to denervation in summer-active bears was comparable to that occurring in other mammals. Whole-muscle cross-sectional
areas (CSAs) measured from ultrasound images and myofiber CSAs measured from biopsies decreased similarly to
musculotendon mass. Thus, hibernating bears alter skeletal muscle catabolic pathways regulated by neural activity, and
exploration of these pathways may offer potential solutions for disuse atrophy of muscles.

[brobear]

by Blaire Van Valkenburgh - First posted by grraahh - shaggygod.proboards.com/

SPEED AND STRENGTH


All bears have a large head with small ears followed by massive shoulders and a short back and | tail, all of which are supported on thick limbs and broad paws. Compared with big cats, bears have longer snouts and shorter, stiffer backs. Relative to large dogs, bears have bulky legs and much more spreading feet. Unlike these other carnivores, and more like humans, bears walk on the soles of their hindfeet, with their ankle joint positioned just above the ground. This condition is called plantigrade, and differs from the digitigrade posture of cats and dogs, in which the “soles” of the feet are elevated, along with the ankle, and only the toes touch the ground. To understand why bears are built so differendy from cats and dogs, it is essential to explain the benefits of digitigrade feet.

Running around on your toes in a digitigrade posture is advantageous if speed is important. Speed is the product of stride length and stride frequency. Raising the ankle adds length to the part of the limb that determines stride length, that is from the shoulder or hip to the point of contact with the ground. Longer limbs take bigger strides, and digitigrade posture is therefore typical of mammals designed to run. Digitigrade animals also tend to have relatively long bones, or metapodials, making up the sole of the foot, adding further to total limb length. In addition, their limb muscles are much thicker close to the hip or shoulder joint, and taper towards the toes as long, elastic tendons. This construction reduces muscle mass near the ankles and feet, where the limb travels farthest during locomotion, and thus reduces inertial effects.

A The skeletons of a bear and a domestic dog illustrate the difference between plantigrade and digitigrade postures. The dog is digitigrade, standing on its toes with the soles of its feet (metapodials) off the ground. By contrast, the soles of the bear's hindfeet are flat to the ground, as in humans, giving it a plantigrade posture.

If one imagines the additional energy required to walk or run with ankle weights or heavy shoes, then the drawbacks of heavy feet become clear. There are yet further benefits to runners in having long tendinous muscle attachments. Tendons are elastic and act as energy-saving springs when running. They are stretched as the limb is flexed under the weight of the animal and then rebound, propelling the body forward and upward. So, digitigrade posture, long metapodials, and compact muscles with stretchy tendons are typical of carnivores built for speed.

Bears are clearly not built for speed. Although their forefeet are semi-digitigrade, their hind-feet are plantigrade. Moreover, their metapodials are short and their muscles thick throughout the length of the limb. In many ways, bears are built more like badgers than other similar-sized carnivores, such as tigers, and it shows in their speed. The top speed recorded for both black and brown bears is 50 kilometers (30 miles) per hour, whereas the range for the fully digitigrade lion and wolf is 55 to 65 kilometers (35 to 40 miles) per hour.

If bears are not built for speed, then what does the combination of massive limbs, plantigrade hindfeet, cumbersome paws, and a short back provide? Strength and mobility of limb movement are the answers. The stout limbs of bears are capable of producing large forces over a much greater range of motion than those of dogs or even cats. Bears use these capabilities when digging for food or shelter, fishing for salmon, climbing to escape danger, and battling with members of their own species as well as other predators. Imagine a wolf trying to perform a bear hug or climb a tree. Dogs have forfeited these abilities in favor of speed. Cats are more like bears in their range of possible movements, but lack strength. Bears may not be able to outrun danger, but can successfully defend themselves through brute force.

[brobear]

From Polar.... I do not know about the denser muscles, where is that study? Some individual muscle fiber types are denser than others, but a bear's muscle is no denser than that of a tiger's, and by that logic should be no denser than that of a human's. This goes for all bear species as well.

Polar bears have greater pulling strength at weight parity due to thicker forelimbs (like big cats), especially in the biceps areas. Not to mention the polar bear has a greater humerus/radius ratio than any other extant bear, giving it a leverage advantage. For pound-for-pound strength between brown and polar bears, it's a toss up, IMO.

*From me ( brobear ).... Polar; about post #29. You first posted the study somewhere at: wildfact.com/forum/
What topic were you on when you were talking about bears retaining their strength when past their prime?

[brobear]

From Frank321....
The author makes an effort to show the tremendous quality of muscle and skeletal frame of the ursines. We need to look at bear behavior to find out why bears need such muscles, rather than making the assertion based on accounts at first, in order to show that this is what bears are designed for. We'll use the diet of American black, brown, and polar bears to recognize these adaptions.

Ursus americanus (Omnivorous)

Honey, beetles, ants, roots, twigs, buds, and on rare occasion, meat, including young elk.

Ursus arctos (Omnivorous)

Peaches, apples, apricots, salmon, elk, musk ox, occasionally bison, sedge, and other vegetation.

Ursus maritimus (Mostly Carnivorous)

Ringed seal, bearded seal, beluga whale, walrus, narwhal, and rare vegetation.

While it might seem obvious which one of these is the most impressive in regards to strength optimization based on diet, things are actually the exact opposite. To understand this, let's review the basic properties of leverage for a quick moment; the longer a lever, the less the strength or weight allowed on the lever, although the greater the speed at the end of a lever.

As we can see, strength optomization in regards to ursines is the exact opposite from impressness in diet; black bears have the best leverage for strength, and polar bears the worst. At least, in terms of limb length anyway. So now, the question why must be asked. We will find this answer by looking at the habitat of each ursine. Black bears can be found in areas such as forests; generally with a lot of trees. Brown bears are more closely associated with areas such as the bottom of river valleys, and fields of sedge. Polar bears are found in more remote areas and circumpolar regions. It seems that, in areas that are more condensed such as forests, and have many rocks and the like we will find animals with shorter limbs, if not relative to their families. This can be seen with the felidae, in which the lion has the longest limbs of the Pantherinae living in open fields, whereas jaguars have relatively the shortest living in condensed forests with rivers and boulders. This would mean that, to flip over heavy boulders and swim through powerful currents and the like, while still maintaining the strength to climb trees, animals who live in forests will generally have shorter limbs. Whereas, in more open areas, where such things are irrelevant, and speed really matters we will have animals with longer limbs being adapted for speed.

Now that we have looked at the diet of bears, and how this influences leverage (strength and speed), we will look at their threats and predators and how this influences their behavior to threats and how it affects them as in regards to evolving to deal with them.
Black bears are generally not very large relative to the apex predators the coexist with. For example, in what is now a part of the old USSR Siberian tigers will prey on them. They aren't well adapted to deal with these massive cats and are generally the submissive ones, the book Mammas of the Soviet Union supports this with accounts of tiger-Asiatic black bear interaction.

They do have defenses. Asiatic black bears are better climbers than Siberian tigers due to having claws better adapted to do so; they escape the threat of a tiger generally by climbing, and because of this are less likely to be preyed on by them (although it has happened.) This is supported by once again, the book Mammals of the Soviet Union.

So now how does the Manchurian brown bear evolve to deal with a predator which it can't climb from to escape, and is too fast to outrun. It evolves to deal with it in a confrontation; brown bears have evolved thick, loose fur around their necks to protect them from tiger bites, and their thick fur on their torso and limbs gives them good protection against the claws of tigers and other ursines. They have also evolved into bulkier animals which are more heavy-set (will be discussed more in section 2.2 and 3.0.)

Grizzly bears coexisted with Machairdontinae felids during the Pleistocene; it's likely grizzlies didn't evolve to deal with these felines due to the fact they wouldn't prey on them because they needed larger prey and would perhaps have difficulty catching them as well.

In the following sub-sections, we will look at the anatomy of bears, and for section 2.3 brown bears respectively. This will allow us to make connections to the neuromuscular evolution which we made earlier.
We will start out with the chest of ursines and compare them with felids. The lion will be the first animal we start out with - the book Into Africa [pg. 41] by Dr. Craig Packer gives the chest girth estimate for a Serengetti lion, it writes- His chest girth is 48 inches. His weight must therefor be be about 350 pounds, fairly average for a Serengetti male.

This is the exact estimate made for 350 pound American black bears in Pennsylvania (Alt 1980), from this - . The more massive chested grizzly bear beats both the lion, and its cousin the American black bear in this regard, credits to Ursus arctos for the following (it should be noted these bears would have had a good amount of body fat when captured, due to being caught in fall, rather than spring where they are at their most muscular)-

As a general consensus however, most all species bear seem to have chests larger than hypercarnivores relative to body size including the felidae when considering largest, or most dominant individuals. Evidence of this is shown in the book Black Bear Hunting on pages 18 and 19-

Manitoba's heaviest bear was by a car on the Province's route 11 near Traverse Bay on the southeast end of Lake Winnipeg during the evening of August 30, 2001. The carcass wasn't officially weighed until September 5, according to Department of Conservation Wildlife Technician Trevor Barker at Lac du Bonnet, and it tipped the scales at 856 1/2 pounds then. Based on a loss of fluids before the bruin was weighed, the animal had an estimated live weight of 886.5 pounds... ... The chest girth was 6.5 feet.The right front paw was 5 1/2 inches wide and rear foot was 9 7/8 inches in length.

We can compare the chest girth of this black bear (estimated fluid weight) with other tigers using mathematics. The chest girth of tigers and lions comes from the book Thirty-seven Years of Big Game Shooting in Cooch Behar, the Duars, and Assam (credits to the Bold Champ for finding it, and Ursus arctos for supplying it to Carnivora), the conversions will be made in this chart-

[brobear]

Continued....
183 kilogram tiger, -
2.2^(1/3)=1.300
119+30%=155

200 kg tiger,-
2.01^(1/3)=1.26
130+26%=164

230 kg tiger,-
1.75^(1/3)=1.21
137+21%=165.77

191 kg tiger,-
2.11^(1/3)=1.28
130+28%=166.4

225 kg tiger,-
1.8^(1/3)=1.22
131+22%=159.82

187 kg lion,-
2.2^(1/3)=1.300
147+30%=191.1
Tiger mean=162.2 centimeters (five individuals)

Lion mean=191.1 centimeters (one individual)

Overall feline mean= 167.015 centimeters (six individuals)

[brobear]

Only a particular lion approached the black bear in chest girth, and all tigers didn't come close. We can compare the chest girth of 866.5 pound black bear relative to other brown bears from charts the book California Grizzly and a chart listing seperate chest girths of brown bears (credits to the bold champ, Ursus arctos, and Warsaw for providing this information.)



The book California Grizzly had the estimated bear's median at 250 kilograms (227-270 kilograms) with a chest girth of 180 centimeters, this will be used when calculating this particular bear's chest girth.

225 kilogram grizzly (male),-

1.61^(1/3)=1.21

180+21%=217.8

115 kilogram grizzly (female),

3.5^(1/3)=1.52

105.5+52%=160.6

115 kilogram grizzly (female),

3.5^(1/3)=1.52

96+52%=145.92

85 kilogram grizzly (female),-

4.61^)1/3)=1.67

87.5+67%=146.125

145 kilogram grizzly(female),-

2.8^(1/3)=1.41

112+41%=158

151 kilogram grizzly (female),-

2.67^(1/3)=1.4

114+40%=162.15

150 kilogram grizzly (female),-

2.7^(1/3)=1.4

129+40%=180.6

115 kilogram grizzly (female),-

3.5^(1/3)=1.52

107.9+52%=164.02

112 kilogram grizzly (female),-

3.6^(1/3)=1.53

99.5+53%=152.24

75 kilogram grizzly (male),-

5.37^(1/3)=1.75

103+75%=180.25

145 kilogram grizzly (male),-

2.8^(1/3)=1.41

113+41%=145.23

145 kilogram grizzly (male),-

2.8^(1/3)=1.41

112+41%=157.91

200 kilogram grizzly (male),-

2.01^(1/3)=1.26

155+26%=195.3

200 kilogram grizzly (male),-

2.01^(1/3)=1.26

146+26%=184

100 kilogram grizzly (male),-

4.03^(1/3)=1.6

97+60%=150.3

135 kilogram grizzly (male),-

3.0^(1/3)=1.44

123+44%=177.12

130 kilogram grizzly (male),-

3.1^(1/3)=1.46

100+46%=146

100 kilogram grizzly (male),-

4.03^(1/3)=1.6

126.5+60%=202.5

57 kilogram grizzly (male),-

7.1^(1/3)=1.92

80+92%=154

275 kilogram grizzly (male),-

1.4^(1/3)=1.2

145+12%=162.4

female chest girth mean=158.71 centimeters (eight individuals)

male chest girth mean=172.73 centimeters (12 individuals.)

Black bear mean=198.12 centimeters (one individual.)

Overall bear mean=174.7 centimeters (21 individuals.)

[brobear]

Continued....
Forelimb girth for felids and usrines, is a more complicated matter, as there seems to be a lack of information on bears. However, according to many posters, Royal Leo posted information which showed that black bears are similar to tigers in forelimb girth, and larger than lions relative to size, although grizzlies had larger girths than all of these animals. This information comes from, bcw3, and 221extra (as a note, 221extra hasn't talked about the study, although he has confirmed he did in fact post it.) However, while we will use Royal_Leo's study, I would like to post a pictorial comparison Ursus arctos created in order to show relative arm girth. However, for this actual the study we won't assume the difference in arm girth is as large as that suggested by the pictures, as Royal Leo's study seemed to contradict this according to posters-

It's time to look back at the leverage scenario once more, felines have greater leverage for strength than similar-sized ursines (see chart in section 1.0), due to having shorter limbs, however ursines have slightly larger arm girths relative to body size. What does this mean, and why? To understand this we need to look at the volume. We know that if we want to increase the limb weight of an animal, we must either make it wider, or longer in order to increase volume for weight. In both of these aspects, ursines are superior to felids, as in having wider, although longer limbs. However, there's a catch, how do we know that the forelimbs of ursines aren't fat, which although takes up more space than muscle, is lighter. This was proven in my analysis "Comparitive Relative Strength of Bears and Cats" where it was shown that the far bears pack on in winter is sent to their hips, rather than forequarters ( www.asbweb.org/conferences/2007/425.pdf ).

So now another question must be asked, why not simply gain the greater relative weight in the limbs by increasing volume more so vertical, than horizontal? We must look at the kinetic energy, and leverage for this answer.

The formula for kinetic energy is - KE= 1/2*m*v^2 - so how is this relevant to ursines? We must look back at the basic properties of leverage -
While increasing the length between the end of a lever, and its fulcrum will increase the speed, it will decrease the strength. The reverse is true when decreasing the distance between the fulcrum and the end of a lever, of course.

In this regard, ursines have the leverage advantage in velocity for kinetic energy when concerning limb movement against felids, and it's likely this is the reason for missing out on the greater strength provided by simply increasing limb weight horizontally.

By all accounts, there doesn't seem to be another animal similar in size to ursines which can deliver as devestating a blow, there is evidence to suggest this in the book Black Bear Hunting., Richard P. Smith : pg. 31-32-

Although most black bears limit their predation to young animals, some larger adult males learn to catch and kill animals as large as moose. Most people might scoff the idea of a 300- to 500-pound bear attacking a moose weighing over 1,000 pounds, but it does happen. Predation on adult moose by large male bears has been documented a number of times in Canada.

Ontario bear researcher Dr. Martyn Obbard and his colleagues documented predation of an adult cow moose by an adult male black bear on the Chapleau Game Reserve during May 1992. A report of the incident was published in the volume 108 of the Canadian Field-Naturalist. In the case of the adult moose being killed, the predatory bear was an 18-year-old male weighing about 300 pounds and fitted with a radio collar... One other Canadian province where black bear predation has been documented is Newfoundland. A researcher there, Shane Mahoney, told me he has recorded a number of cases where adult male bears weighing 300 to 350 pounds have killed adult moose and caribou. One instance he mentioned involved an adult moose that was attacked by a large male as it bedded like the one in Ontario. In that situation, the bear killed the moose with a blow to the back from a paw, smashing the spine... A big bear was actually observed killing a cow moose in the water during another case of predation. Mahoney said the water was too deep for the bruin to get much leverage where the moose was originally attacked, but as the moose move toward shore and got into shallow water, odds turned in the bear's favor. Once the bruin was able to get to its feet on the bottom, it brought the cow down with a swatt to the spine.

[brobear]

Continued....
To start out with this chapter, I would like to look at the length of a ursine and felid's back, on average (credits to Taipan), and the following table is from largest to smallest in meters-

lower-upper
Tiger 2.20 3.30
Lion 2.00 2.80
Cougar 1.00 2.00
Leopard 0.90 1.90
Jaguar 1.00 1.80
Cheetah 1.00 1.50
Snow Leopard 1.00 1.30
Lynx 0.80 1.30
Asian Golden Cat 0.73 1.10
Serval 0.67 1.00
Bobcat 0.65 1.00
Clouded Leopard 0.60 1.00
Ocelot 0.55 1.00
African Golden Cat 0.72 0.95
Chinese Desert Cat 0.68 0.94
Caracal 0.60 0.90
Fishing Cat 0.72 0.86
Margay 0.45 0.80
Jaguarundi 0.60 0.77
Jungle Cat 0.60 0.75
Wild Cat 0.50 0.75
Pampas Cat 0.56 0.70
Geoffrey's Cat 0.45 0.70
Pallas Cat 0.50 0.65
Bay Cat 0.50 0.60
Iriomote Cat 0.50 0.60
Andean Mountain Cat 0.48 0.60
Leopard Cat 0.44 0.60
Sand Cat 0.45 0.57
Litle Spotted Cat 0.40 0.55
Flat-headed Cat 0.40 0.55
Marbled Cat 0.45 0.53
Black-footed Cat 0.40 0.50
Kodkod 0.38 0.48
Rusty-Spotted Cat 0.40 0.45

[brobear]

Continued....
Now to compare it to that of ursines, the book The Great Bear Almanac by Gary Brown, lists the length of ursines on page 64, I will make a list giving these lengths-
American black bear 4-6 feet, brown bear 7-10 feet, polar bear 8-8.4 feet, Asiatic black bear 5-7 feet, giant panda 5-6 feet, sloth bear 5-6 feet, sun bear 3-4.5 feet, spectacled bear 4-7 feet.
Relative to ursines, felids seem to have much longer backs. So once more, the question must be asked, what does this mean? It shows bears are more powerfully built in their back; looking back at the properties of leverage once more, we know that shorter levers allow more weight to be placed on a lever, the shorter back of a ursid allows the spinal cord to hold greater amounts of muscle than felids.

This is shown in the height of the back of the families, where much smaller ursids can have backs as high as those of the largest felines as shown by this source (http://www.americanbear.org/Size.htm)-
The height of a bear is measured from the bottom of its paw, flat on the ground, to the highest point of the shoulders. An adult male American black bear will measure between 2½ and 3 feet tall. This is approximately the same height as a Siberian tiger.

[brobear]

Continued....
Since limb bones are placed vertical however, unlike the spinal cord, leverage to support more amounts of muscle in this area is irrelevant. However, there must be an advantage to having a longer backs, or else evolution would supply all quadrupeds with shorter backs. There is; having a longer back increases stride length in quadrupeds, and stride length is directly correlated with speed since speed is stride length*frequency. This means, at least in the back felids are better adapted for speed than ursines, and suggests so overall as well.

This also suggests ursines once again, have an adaption for producing tremendous force in their paw swipes, since delivering a paw swipe contracts the muscles in an animal's back, and more amounts of muscle allows greater force to accelerate with, and force and acceleration are directly correlated. We know this via Newton's second.

Now, for the abudctor muscles. Earlier in this thread it was shown that all (or the majority of) the fat that bears gain during fall is sent to the hips. This seems to be supported by images as well. Felines on the other hand, would presumeably have more muscle than fat in this area due to having relatively less fat than bears throughout the full cycle of seasons (perhaps except the Siberian tiger, although this animal might have fat sent to other areas other than the hips, needing its hindquarters as springs to leap onto prey.)

Information on the abductor muscles of both animals, however is quite limited and we'll have to wait until more data arises until we can make a more comprehensive comparison.

[brobear]

Shoulder Hump****

This section will be given to the brown bear amongst ursines soley. We'll start out with a quote from the Great Bear Almanac, by Gary Brown on page 77-
Brown bears have a hump between their shoulders that is covered with long hairs and is normally a reliable means of species identification. The long hair often accentuates the hump when "the hackles" are raised. This distinguishing feature is a distinctive mass of muscle that provides the brown bears with their digging ability and the powerful striking force of the forepaws.

Once again, another part of brown bear anatomy (although other bears have similar features which shows why they can accomplish similar feats) which allows for tremendous striking force of the paws. However, this extra muscle also allows extra strength, as have other features such as the shortened back, greater amount of muscle in the limbs of bears, and leverage advantage in paw striking.

Other ursines such as the black bear and polar bear, have this feature abridged, and felines lack it entirely. How large can the shoulder hump get however? Let's find out how high first, this source mentions how the bear's height is measured and than gives it (http://internationalhunte.../InteriorBearAnatomy.html)-

The brown bear is 3-5 feet, from the bottom of the paw to the highest point at the shoulder. We can subtract this height from the limb length of Ursus arctos in the chart shown in section 1.0 to find the height of the shoulder hump. Ursus arctos's forelimb length is 2.857, subtracting this from three and five feet gives us a range of .143-2.143 feet. I would assume that only the largest bears would of roughly half a ton in weight would have a shoulder hump of two feet, whereas only the smallest would be within the range of .143 of a foot. However, since maximums and minimals don't particularly show averages, we will search for the average height of the grizzly, this source (http://www.bearinfosite.com/brown_grizzly_bear.htm ) gives an average- The adult bear is generally 3 1/2 feet tall when on all fours.

[brobear]

Continued.... Now, to minus the limb length, 3.5-2.857=0.643. This should mean that the brown bear's shoulder hump is about 6 inches tall, at average (or at least, when the hump is erect, which it will be in some phases of running or digging.) Now, to find out how wide. While I don't have any evidence of this, pictures seem to clearly show a brown bear's shoulder hump is noticeably wider than it is high.
So when we calculate how wide the shoulder hump of a brown bear is, we will use the term "at least wider than", since the shoulder hump of a brown bear is wider than it is tall. Now than, we know the shoulder hump of an average brown bear is at least wider than six inches, but what is the actual circumference of the hump? Having a hump at least wider than six inches, we can use pi to find out (note that we will use pi to the hundred-millionth unit.) 6*pi=18.84955592153876. However, since the shoulder hump is only half a circle, due to meeting with the back before completion, we must divide this by two- 18.84955592153876/2=9.42477796. So we now know that the shoulder hump of an average brown bear should at least have a circumference greater than 9.42477796 inches. Now, another question must be asked, what is the area of a an average brown bear's shoulder hump? We can find this by multiplying pi by the radius squared. So, pi*3^2= 28.27433385. However, since once more the shoulder hump of a brown bear is only half a circle we must once more, divide by two, so 28.27433385/2=14.137166925.

Now the important phase, I would like to find out the weight of a brown bear's shoulder hump. The area of an average brown bear's shoulder hump is greater than 14.137166925 inches, or 1.17809724375 feet. How much area will this many feet of a brown bear weight. We will be using the grizzly bear in this scenario, since brown bear size is extremely fluctuating. This source (http://www.defenders.org/...wildlife/grizzly_bear.php ) says the average grizzly is 6-7 in length, and gives a median of 575 pounds. Now, to give an approximation of the weight of a grizzly bear's shoulder hump, we will divide the average weight of the bear by its average length. We aren't done yet however, we must also take into account a bear's fore- and hind limbs, as these make up some of the bear's weight as well, rather than just the torso. To account for the bear's hind and forelimbs, we will multiply the forelimb length and hind limb lengths given by the chart in the "Neuromuscular evolution" thread by two, and add them together, than add them to the bear's torso length. 2.857*2= 5.714, 2.802*2= 5.604, 5.714+5.604= 11.318. So, now we will add this length to the range of the bear's torso length, 11.318+6= 17.318, 11.318+7= 18.318. Now, we will divide the bear's weight by this length to find out how much weight a bear gains when it gains a foot in length, 575/17.318= 33.20244839667398082919505716595, 575/18= 31.944444444444443. So, every other foot added onto a bear should give it a gain of 33.20244839667398082919505716595-31.944444444444443 pounds. Now, to find our estimation for the shoulder hump weight we can stimply add on 17.809724375% of the weight our ranges gave us for per square foot of a grizzly bear.
So, 33.20244839667398082919505716595+17.067652520105092%= 38.8693269, and 31.944444444444443 +17.067652520105092%= 37.3966112. However, it should be noted since seven feet was the upper weight range in length for a bear, we're likely talking about a bear closer to 625 pounds with the shoulder hump weight estimate, and since the shoulder hump of a bear lacks bones, in order to optimize muscle attachment, the overall weight will also likely (although not necessarily so, because bears for the most part, have all muscle in their shoulder hump, whereas the hips of a bear will show less weight per square foot due to the fact that's where the fat of a ursine is, and fat weighs less than muscle) be on the lower end of the estimation.

Now, we can make a chart listing the statistics of a brown bear's shoulder hump.