Many artists have channeled physical and/or mental suffering into their art. Frida Kahlo depicted painful surgeries after a streetcar accident left her with lifelong physical ailments. Though definite diagnoses are elusive, it’s been speculated that Van Gogh suffered from any of a number of conditions – among them epilepsy, lead poisoning and Ménière’s disease. In the 1960s, Sam Francis painted his “Blue Balls” series, which dealt with his hospitalization and convalescence from kidney disease.

Now at the University of New England Art Gallery in Portland we get “Tenacious” (through June 11), a show curated by Tilly Laskey and featuring four Midcoast-based artists. At least two, Karen Jelenfy and James Graham, live with chronic physical ailments. The others, James Bradley Marshall and Ian Trask, do not reveal any obvious health or mental issues in their statements, yet they do talk about art as a way of processing contemporary ills such as environmental crises and, in Marshall’s case, an aversion to the art world’s “gilded cultural status, self-indulgent seriousness and pretentious gravitas.” (Hear, hear!)

For all these artists, art-making is a way of striving toward resolution or acceptance around the issues with which they grapple, working through frustrations or limitations, and searching for meaning amidst a sense of helplessness. The title refers not only to the strength and determination of their response, but also to their artistic practices, which tend to be obsessively repetitive and/or summon enormous emotional and physical will.

Marshall is best known for his sculptures, which look like metal and imply tremendous weight. In actuality, they are quite light and delicate, assembled from paper bags that have been stiffened and hardened with polyvinyl acetate and graphite-infused plaster. While they certainly accomplish what he calls a “gotcha” moment, they also challenge the shaky, fragile foundation of anything we hold as fixed or static: truth, identity, health, life, positions and beliefs, the nature of reality.

“Artist’s Muse,” for example, appears solid and hard. Yet its component bags seem to teeter precariously, especially when we notice that one of them is starting to folk in on itself. We marvel at how the whole thing doesn’t collapse onto the floor.

But the pieces that really knocked me over were Marshall’s “Drawing on Purpose” works, where he has compulsively drawn his pencil in circle after circle to create a series of shiny black discs. Each disc must have taken tens, if not hundreds, of repetitive circular motions, the consistent pressure of which has soaked the paper with graphite and bubbled it into a bas-relief effect. The single-minded resolve of this process knocks the wind out of you. I literally gasped.

Karen Jelenfy’s paintings are a response to our inexorably disappearing glaciers due to global warming. The artist suffers from fibromyalgia and neurological health conditions. It is hard enough not to despair about this depressing phenomenon when one is hale and hearty, but harder still from a position of such physical vulnerability and unpredictability. However, Jelenfy isn’t taking it, as the saying goes, lying down. Mostly abstract, one can nevertheless intuit mountains and rock faces. There is a palpable ferocity to her mark-making and the way she attacks her surfaces with paint and pencil.

I say “attacks” because there’s no other word for it. Her surfaces feel exhausted by the constant exertion of holding up against the energy of her gestures. There is nothing ambivalent about them; they are forceful and confident. The works on paper or unstretched canvas, especially, look like they’re curling in on themselves in self-defense. “Sour Summer” is all frenetic action. You can feel her putting her whole body into each stroke.

There is modest relief in areas of some of Graham’s paintings, particularly those involving thinned-out washes of acrylic paint, or looser, gracefully arching gestures. But for the most part, the canvases of this artist, who lives with complications of neurological Lyme disease, are just as fiercely worked as Jelenfy’s, in his case with a variety of brushes and palette knives that often layer on thick impastos of color.

“Ultimately my work negotiates the fight between chaos and order,” reads his statement, and you can certainly sense that. All except one are called “Untitled,” the exception being the much more controlled and constructed “Superations Ad Nauseum,” which he did before the onset of his illness. Certainly for Graham, this must be a daily struggle. But it is also a primal one.

There is a portentousness to some of his work, particularly an untitled painting swimming predominantly in greens and blues with whisps of white, lavender and magenta. The agitation and thickness of the brushstrokes gives the impression of an angrily roiling sea. In the center, Graham has taken a five-sided shape that looks cut from another, lighter work and pasted it to the surface. The effect is of a small sailboat being tossed amongst the crests and troughs of the menacing waves.

Another painting looks like a pine tree rendered in sweeping strokes against a ground of reds, yellows, oranges and blacks. The background intimates an approaching forest fire that threatens to engulf the tree in flames. These are all fairly large canvases and, like with Jelenfy’s, we intuit the participation of Graham’s whole body – an obstinate effort considering his Lyme. They are energetic, enlivening and unabashedly beautiful in their depiction of this ceaseless struggle for order amid chaos.

Most viewers will be familiar with Trask’s “Spore” sculptures – composed of many spheres bundled together from discarded fabrics, mesh, blankets and other soft goods and suspended in strands like chains of DNA or in shapes such as spheres. There is one of these here, a site-specific piece that hangs in the stairwell. It’s terrific, of course.

But much more interesting to me are his assemblages, which I’d never encountered. Like the “Spores,” these are about our throwaway culture, a form of dignifying what we devalued in casting off by giving it new contextual meaning as art. It is an uplifting, positive approach, not to mention useful in diverting the materials of his art from a landfill or our oceans. Trask calls it, fittingly, “resourceful optimism.”

Indeed, as art, this former refuse is transformed. “Protean Folds” is mesmerizing. It consists of bits of leather, suede, faux leather and perhaps other materials, each placed by itself in a little glass vial. Trask then takes 360 of these vials – five columns of 72 vials each – and arranges them in a vertical grid that is then framed.

There is so much about this piece that is intriguing: its mathematical calculation, the obsessiveness of ordering and assembling, the way the vials recall scientific specimens (Trask studied biology), the impression they give of being like reliquaries containing sacred objects. It put me in mind of the art of the late New York artist Barton Lidice Beneš, who created miniature “museums” of celebrity objects – a crumb from Prince Charles and Diana’s wedding cake, pieces of Elizabeth Taylor’s shoe – similarly assembled in boxes.

Another wonderful piece is “Row Planting,” which looks like a more structured Joseph Cornell. At the back of an old wooden box that came from an army tank (revealed by the lettering of its ammo contents on the side), Trask has threaded a notions ribbon around what look like gears made of electrical tape, which gives the appearance of a perpetual motion machine. Before this is a grid made of silver wire that suspends seeds at its vertical and horizontal points of intersection and, closest to the viewer, several tensile cables wrapped in green thread.

The title’s reference to agriculture explains the orderly placement of seeds. But the tape and gears might suggest an underlying natural system that powers the mechanism of growth. The wrapped cables might imply rows of plants above the surface.

Then again, it might mean none of this. But whatever is intended, both of these works feel like something enshrined that is worthy of consideration as art rather than garbage. There is tenacity to their insistence on deeper relevance beyond ephemera. But I also couldn’t help thinking of the artist’s tenacity in doggedly pursuing his “resourceful optimism” against the sheer tonnage of trash we turn out each second. Still, these objects ultimately embody a kind of quixotic stubbornness against an unfairly matched opponent. Which, of course, makes them all the more poignant.