Harris Dickinson, Maura Tierney, Holt McCallany and Lily James also star in the elegiac salute to the Von Erichs, a Texas sports dynasty walloped by a string of tragedies.

In the opening flashback scene of The Iron Claw, the patriarch of a Texas family meets up with his wife and two young sons outside a wrestling arena where he has just pulverized an opponent using the signature vise-like skull grip that gives the film its title. The boys sit in rapt attention in the backseat of the car, hanging off their father’s every word as he makes a solemn promise to their mother that once he wins the world championship title, their hard times will be behind them.

Anyone who followed American professional wrestling in the 1980s and early ‘90s will be familiar with the devastating story of the Von Erich clan, relentlessly driven to dominate the sport by the wrestler-turned-promoter and coach who took the name Fritz Von Erich (Holt McCallany). But the cost was enormous, enough to break most families, and the fact that one son, Kevin (Zac Efron) — whose perspective is the story’s narrative lens — endured at all despite unimaginable pain and loss and grief tempers the film’s sorrow with notes of resilience and hard-won peace.

Durkin’s third feature is more than competently executed, with a solid ensemble cast and a vivid sense of place and time, without overdoing the needle drops. But considering the shattering blows delivered to the Von Erichs at regular intervals throughout the story, its emotional impact feels oddly muted. At least that’s the case until the final stretch, and even then, the pervasive sadness feels less fluidly woven into the drama than conveyed in isolated scenes — a mother unable to put on her black funeral dress one more time; a brother broken by the fates of his siblings but receiving comfort from the pure love of his own sons.

It’s almost as if the constraints of portraying real people and the responsibility of showing respect for their suffering has held back Durkin’s willingness for psychological exploration.

Early on, Fritz freely admits over the dinner table to his four assembled sons that he has his favorites. “But the rankings can always change. Everyone can work their way up or down.” That should provide the template for a drama in which fraternal bonds go head to head with sibling rivalry. Instead, the relationships among the brothers mostly feel under-sketched, their individual characters lacking dimension.

Even at two hours-plus, there’s not enough breathing space between tragedies to allow them to resonate to the extent they should. Durkin has his hands full just chronicling the staggering run of misfortunes that causes Kevin to fear a family curse. So larger themes such as the blind belief in American exceptionalism, the delusions of masculine invincibility, the suppression of grief and the suffocation of a father’s ambitions for his sons don’t fully cohere. Durkin references Greek tragedy in his conception of the film, but that element within the wrestling milieu was more persuasively suggested in Foxcatcher.

Tragedy already hangs over the family when the mainframe drama begins, with memories of the first-born son of Fritz and his wife Doris (Maura Tierney), Jack Jr., who died in a freak accident at age six. Fritz’s attentions have settled on Kevin, who has talent in the ring, but lacks the mouthy braggadocio of a true showman on the mic, something in which his younger brother David (Harris Dickinson) excels.

His championship dreams eclipsed by David, Kevin is passed over again when next-in-line Kerry (Jeremy Allen White), a promising athlete, sees his Olympic hopes dashed by the 1980 U.S. boycott and takes up wrestling with fierce commitment. Finally, youngest son Mike (newcomer Stanley Simons), an easy-breezy kid whose college garage-band pursuits make him seem immune to the cauldron of testosterone and unsuited to competitive sports, gets bitten by the family bug. Or injected with it by his father.