Forest terrains influence walking kinematics among indigenous Tsimane of the Bolivian Amazon

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The distinct kinematic features of human bipedal walking that contribute to enhanced economy include extended hip and knee joints, narrow step widths, and heel-first foot strike postures.

“The distinct kinematic features of human bipedal walking that contribute to this enhanced economy include the use of extended hip and knee joints, narrow step widths, and heel-first foot strike postures (O'Neill, Demes, Thompson, & Umberger, 2018; Pontzer, Raichlen, & Sockol, 2009; Thompson, O'Neill, Holowka, & Demes, 2018; Webber & Raichlen, 2016).”

• cites O'Neill et al., 2018 sourcePartly supported

  Section 3.2 reports that humans walk with more extended hips and knees than the compared chimpanzees and macaques. Section 4.3 says greater lower-limb extension may lower walking’s metabolic cost, and section 4.1 describes a distinct human heel-strike posture. The paper does not establish narrow step width or heel-first foot strike as contributors to enhanced economy. (LLM, conf=0.87)

  Experimental — accuracy not yet measured
• cites Pontzer et al., 2009 sourceCould not verify

  The Discussion addresses daily movement distance, energy budgets, and reproductive investment across mammals, not the mechanics of human bipedal walking. Searches for extended joints, narrow step widths, heel-first foot strikes, and walking economy found no passage in our copy addressing those features. The cited sentence names Pontzer, Raichlen, and Sockol (2009), whereas the source supplied here is by Pontzer and Kamilar. (LLM, conf=0.76)

  Experimental — accuracy not yet measured
• cites Thompson et al., 2018 sourceNot checked — no full text of the source

It may state two separate claims as one.

Shorter individuals may need to make fewer adjustments to their standard walking kinematics in forests, which could provide an additional selective force for reduced stature in forest-dwelling populations alongside reducing constraints on step length.

“This result suggests that shorter individuals may need to make fewer adjustments to their standard walking kinematics in forests, which could provide an additional selective force for reduced stature in forest-dwelling populations alongside reducing constraints on step length (Venkataraman et al., 2018).”

• cites Venkataraman et al., 2018 sourcePartly supported

  Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured

Probably not a substantial claim.

Walking outdoors on relatively simple natural surfaces (e.g. grass, gravel, woodchips) can increase walking costs by up to 27% owing to factors such as stride variability and height of swing foot clearance.

“Walking outdoors on relatively simple natural surfaces (e.g. grass, gravel, woodchips) can increase walking costs by up to 27% owing to factors such as stride variability and height of swing foot clearance (Kowalsky, Rebula, Ojeda, Adamczyk, & Kuo, 2021)”

• cites Kowalsky et al., 2021 sourcePartly supported

  The Results (page unavailable) report that woodchips had a 27% higher net metabolic rate than sidewalk, and the Discussion links stride variability and virtual foot clearance with energy cost. But the paper reports correlations and possible gait adaptations, not that those factors caused the increase; the claim’s “owing to” wording is stronger than the evidence. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Given that humans have longer day ranges than other primates, the use of trails in dense environments (such as forests) is expected to save energy and decrease travel time.

“Given that humans have longer day ranges than other primates (Pontzer & Kamilar, 2009), the use of trails in dense environments (such as forests) is expected to save energy and decrease travel time.”

• cites Pontzer & Kamilar, 2009 sourceCould not verify

  The Abstract and Discussion compare daily movement distances across mammals, but do not state that humans have longer day ranges than other primates. A search for humans and for a human–primate day-range comparison found no passage addressing the cited premise. The expectation about trails is the citing authors’ own inference, not the part attributed to this source. (LLM, conf=0.74)

  Experimental — accuracy not yet measured

It may state two separate claims as one.

Only Matthis et al. (2018) and Kowalsky et al. (2021) have used IMUs to record walking on complex natural terrains outdoors, and neither report joint kinematics in their study.

“To our knowledge, only Matthis et al. (2018) and Kowalsky et al. (2021) have used IMUs to record walking on complex natural terrains outdoors, and neither report joint kinematics in their study.”

• cites Matthis et al., 2018 sourcePartly supported

  The Results and STAR Methods (METHOD DETAILS; page numbers unavailable) confirm that Matthis et al. used IMUs to record walking on rocky outdoor terrain. The passages describe analyses of gaze and foot placement rather than reporting joint kinematics. This paper cannot establish that only it and Kowalsky et al. used IMUs in such settings, or what Kowalsky et al. reported. (LLM, conf=0.83)

  Experimental — accuracy not yet measured
• cites Kowalsky et al., 2021 sourceSupported

It may state two separate claims as one.

Participants used the highest stride frequencies and shortest strides in the open, and the lowest stride frequencies and longest strides in the forest.

“Participants used the highest stride frequencies and shortest strides in the open, and the lowest stride frequencies and longest strides in the forest.”

It may state two separate claims as one.

Across the different surfaces investigated in this study, foot strike angle was associated with ankle angle but not leg protraction angle.

“Across the different surfaces investigated in this study, foot strike angle was associated with ankle angle but not leg protraction angle.”

It may state two separate claims as one.

Trail walking was kinematically intermediate between open field and unbroken forest walking in some respects, including maximum foot height and midstance thigh angle, but was similar to open walking in terms of foot strike angle, trunk inclination and midstance knee angle.

“Trail walking was kinematically intermediate between open field and unbroken forest walking in some respects, including maximum foot height and midstance thigh angle, but was similar to open walking in terms of foot strike angle, trunk inclination and midstance knee angle.”

It may state two separate claims as one.

Taller participants tended to use more flexed hip and knee joints, as well as more inclined trunks, during forest walking.

“Notably, we found that taller participants tended to use more flexed hip and knee joints, as well as more inclined trunks, during forest walking.”

It may state two separate claims as one.

Compared to walking in the open condition, participants walking in the forest had more flexed thighs and knee joints and used greater trunk inclination at midstance.

“Compared to walking in the open condition, participants walking in the forest had more flexed thighs and knee joints and used greater trunk inclination at midstance.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Study participants stated a preference for walking barefoot over using footwear in the forest.

“we note that study participants stated a preference for walking barefoot over using footwear in the forest, perhaps because of the additional sensory feedback afforded by the former.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Human bipedalism has greater walking economy than other primates, including chimpanzees.

“Metabolic studies indicate that a key advantage of human bipedalism is greater walking economy than in other primates, including our closest living relatives, chimpanzees (Nakatsukasa et al., 2004; Sockol, Raichlen, & Pontzer, 2007).”

• cites Nakatsukasa et al., 2004 sourceNot checked — no full text of the source
• cites Sockol, Raichlen, & Pontzer, 2007 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Participants exhibited a 28% increase in rate of energy expenditure when walking on a custom-designed uneven treadmill surface compared with a standard, even treadmill surface.

“One study found that, because of such factors, participants exhibited a 28% increase in rate of energy expenditure when walking on a custom-designed uneven treadmill surface compared with a standard, even treadmill surface (Voloshina et al., 2013).”

• cites Voloshina et al., 2013 sourceNot checked — no full text of the source

Probably not a substantial claim.

Linear mixed effects models for each variable included walking condition and walking velocity as fixed effects and participant identity as a random effect.

“We used the ‘lme4’ package (Bates, Mächler, Bolker, & Walker, 2015) to estimate linear mixed effects models for each variable, with walking condition (‘open’, ‘trail’, ‘forest’) and walking velocity included as fixed effects and participant identity as a random effect.”

• cites Bates et al., 2015 sourceNot checked — no full text of the source

Probably not a substantial claim.

Matthis et al. (2018) found that, when walking on rocky terrain, people maintain their gaze on the ground in front of them roughly 95% of the time to plan foot placement two to three steps ahead of the current one.

“Matthis et al. (2018) found that, when walking on rocky terrain, people maintain their gaze on the ground in front of them roughly 95% of the time to plan foot placement two to three steps ahead of the current one.”

• cites Matthis et al., 2018 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The use of a flatter foot contact and absence of a clear heel strike may affect walking economy by reducing the total distance travelled by the body's centre of mass during a given step and/or increasing the amount of mechanical work needed to accelerate the body's centre of mass between steps.

“The use of a flatter foot contact and absence of a clear heel strike may affect walking economy, as it may reduce the total distance travelled by the body's centre of mass during a given step (Webber & Raichlen, 2016) and/or increase the amount of mechanical work needed to accelerate the body's centre of mass between steps (Adamczyk & Kuo, 2013; Holowka & Lieberman, 2018).”

• cites Webber & Raichlen, 2016 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

• cites Adamczyk & Kuo, 2013 sourceNot checked — no full text of the source
• cites Holowka & Lieberman, 2018 sourceNot checked — no full text of the source

Probably not a substantial claim. It may be too vague to check against evidence. The paper’s conclusions may not depend on it.

The creation and maintenance of trails represents a good example of human niche construction.

“The creation and maintenance of trails thus represents a good example of human niche construction.”

• AssumptionRests on an assumption: The Tsimane treat trails like a public good, with older individuals and village work parties actively maintaining the condition of trails for the good of the community.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Research on other animals, typically conducted using camera traps, has indicated substantial energetic benefits of trail use.

“While there are few studies on human trail use, research on other animals, typically conducted using camera traps, has indicated substantial energetic benefits of trail use.”

• cites Cusack et al., 2015 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

• cites Kays et al., 2011Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

A flatter foot strike posture is under intentional control at the ankle, and is not just determined by more proximal positioning of the leg at foot contact.

“Thus, it appears that a flatter foot strike posture is under intentional control at the ankle, and is not just determined by more proximal positioning of the leg at foot contact.”

It may state two separate claims as one.

Walking under these conditions elicits a gait in which the foot is raised higher and thus the toe is probably further from the ground surface, which decreases the likelihood of it colliding with an obstacle as the leg is swinging forward.

“Walking under these conditions therefore elicits a gait in which the foot is raised higher and thus the toe is probably further from the ground surface, which decreases the likelihood of it colliding with an obstacle as the leg is swinging forward.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

More complex natural surfaces like 'heavy brush' and 'swampy bog' may increase metabolic rates by as much as 50-80% compared with flat surface walking.

“whereas more complex (albeit poorly defined) natural surfaces like ‘heavy brush’ and ‘swampy bog’ may increase metabolic rates by as much as 50–80% compared with flat surface walking (Soule & Goldman, 1972).”

• cites Soule & Goldman, 1972 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

All participants provided informed consent and were compensated, and all study procedures were approved by the institutional review board of the University of California, Santa Barbara.

“All participants in the study provided informed consent and were compensated for their participation. All study procedures were approved by the institutional review board of the University of California, Santa Barbara.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Ethnographers have observed that humans from populations native to dense rainforests walk with crouched postures and high stepping gaits when in the forest in order to avoid both head-level and foot-level vegetation that could cause harm.

“For instance, ethnographers have observed that humans from populations native to dense rainforests walk with crouched postures and high stepping gaits when in the forest in order to avoid both head-level (e.g. branches) and foot-level (e.g. roots) vegetation that could cause harm (Evans, 1937; Garvan, 1964; Schebesta, 1928; Turnbull, 1986).”

• cites Evans, 1937Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Garvan, 1964Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Schebesta, 1928Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Increasing foot height involves greater lower limb joint flexion, which probably requires more muscle activation and therefore higher energy expenditure.

“Increasing foot height involves greater lower limb joint flexion (Schulz, 2011), which probably requires more muscle activation and therefore higher energy expenditure (Kowalski et al., 2021).”

• cites Schulz, 2011 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

• cites Kowalski et al., 2021Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim.

The Tsimane make an ideal study population because they walk through dense forest regularly for common activities such as food gathering, hunting and travelling to horticultural fields or to visit relatives in other villages.

“and make an ideal study population because they walk through dense forest regularly for common activities such as food gathering, hunting and travelling to horticultural fields or to visit relatives in other villages.”

It may state two separate claims as one.

Using trails probably decreases the costs of locomotion and facilitates higher travel speeds.

“In this context, using trails probably decreases the costs of locomotion and facilitates higher travel speeds.”

It may state two separate claims as one.

The individuals in irregular surface studies wore sophisticated, modern footwear such as athletic shoes and boots, which have not been available to our species for most of its existence and probably affect the way we walk on challenging surfaces.

“Perhaps more significantly, the individuals in these studies wore sophisticated, modern footwear such as athletic shoes and boots, which have not been available to our species for most of its existence (Tenner, 2003) and probably affect the way we walk on challenging surfaces.”

• cites Tenner, 2003Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Video-based kinematics impose certain limitations and the sample size was limited by access to willing participants in a remote setting, so this investigation of forest walking is preliminary.

“Video-based kinematics impose certain limitations that we will discuss later, and our sample size was limited by access to willing participants in a remote setting, so we consider this investigation of forest walking to be preliminary.”

Probably not a substantial claim. It may state two separate claims as one.

Recent studies of walking on rocky terrains found individuals significantly reduced their step lengths to achieve more stable foot placement compared with walking on flat, even surfaces, which more than doubled their walking costs.

“Several recent studies of walking on rocky terrains found the individuals significantly reduced their step lengths to achieve more stable foot placement when compared with walking on flat, even surfaces (Gast, Kram, & Riemer, 2019; Matthis et al., 2018), which more than doubled their walking costs (Gast et al., 2019)”

• cites Gast et al., 2019 sourceNot checked yet
• cites Matthis et al., 2018 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Trails may also aid patrolling behaviour in territorial species, although a study of Tai chimpanzees found that they rarely use paths, including while on patrols.

“Trails may also aid patrolling behaviour in territorial species (Cusack et al., 2015), although a study of Tai chimpanzees found that they rarely use paths, including while on patrols (Jang, Boesch, Mundry, Ban, & Janmaat, 2019).”

• cites Cusack et al., 2015 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

• cites Jang et al., 2019 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The use of more flexed hip and knee postures in the forest could increase external joint moments, thereby increasing the volume of active muscle and accordingly energy expenditure during walking.

“The use of more flexed hip and knee postures in the forest could also increase external joint moments, thereby increasing the volume of active muscle and accordingly energy expenditure during walking (Carey & Crompton, 2005; Foster, Raichlen, & Pontzer, 2013).”

• cites Carey & Crompton, 2005 sourceNot checked — no full text of the source
• cites Foster, Raichlen, & Pontzer, 2013 sourceNot checked — no full text of the source

Probably not a substantial claim.

Studies of walking on compliant and slippery surfaces have found that people tend to use more crouched postures to lower the body's centre of mass, potentially to help avoid falls by reducing the moment arm between the centre of mass and ground reaction forces.

“Studies of walking on compliant and slippery surfaces have found that people tend to use more crouched postures to lower the body's centre of mass, potentially to help avoid falls by reducing the moment arm between the centre of mass and ground reaction forces (MacLellan & Patla, 2006; Marigold & Patla, 2002).”

• cites MacLellan & Patla, 2006 sourceNot checked — no full text of the source
• cites Marigold & Patla, 2002 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Trunk inclination could have a broader effect on gait biomechanics as it shifts the body's centre of mass forward slightly, potentially increasing external moments at the hip joint.

“Regardless of the reason, trunk inclination could have a broader effect on gait biomechanics as it shifts the body's centre of mass forward slightly, potentially increasing external moments at the hip joint.”

Probably not a substantial claim.

Without measurements of metabolic energy consumption we cannot determine how much forest walking would increase energy costs compared with walking in the open field.

“Without measurements of metabolic energy consumption we cannot determine how much forest walking would increase energy costs compared with walking in the open field.”

Probably not a substantial claim.

The Tsimane are a forager-horticulturalist society from the lowland Amazon of Bolivia.

“The Tsimane are a forager–horticulturalist society from the lowland Amazon of Bolivia (Gurven et al., 2017)”

• cites Gurven et al., 2017 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

It may state two separate claims as one.

By creating and utilising trails, humans may be able to walk in ways that are kinematically similar to walking on flat, even surfaces, and thus may achieve greater walking economy.

“These results show that, by creating and utilising trails, humans may be able to walk in ways that are kinematically similar to walking on flat, even surfaces, and thus may achieve greater walking economy.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Carnivores and large-bodied predators use trails more than other animals, including their prey, and use large day ranges to hunt.

“Carnivores and large-bodied predators use trails more than other animals, including their prey (e.g. small ungulates; Cusack et al., 2015; Kays et al., 2011), and use large day ranges to hunt (Carbone, Cowlishaw, Isaac, & Rowcliffe, 2005).”

• cites Cusack et al., 2015 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

• cites Kays et al., 2011Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Carbone et al., 2005 sourceNot checked — no full text of the source

It may state two separate claims as one.

Laboratory-based studies simulating natural terrain walking on artificial irregular surfaces generally found that participants use more variable stride characteristics, flatter foot postures at initial contact, higher foot clearance during leg swing, and greater leg muscle activation compared with walking on regular surfaces.

“Generally, these studies have found that, when compared with walking on regular (flat, even) surfaces, participants use more variable stride characteristics like step length and width (e.g. Kent, Sommerfeld, Mukherjee, Takahashi, & Stergiou, 2019; Menant, Steele, Menz, Munro, & Lord, 2011; Voloshina, Kuo, Daley, & Ferris, 2013), use flatter foot postures at initial contact and higher foot”

• cites Kent et al., 2019 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

• cites Menant et al., 2011Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Voloshina et al., 2013 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it.

One to three trials were kept per walking condition per participant, except for three participants for whom there were no analysable forest trials.

“Ultimately, one to three trials were kept per walking condition per participant, except for three participants for whom there were no analysable forest trials.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Laden observed that travelling a given distance off trail takes twice as long as when on human-made trails.

“Laden observed that travelling a given distance off trail takes twice as long as when on human-made trails, and suggested three important functions of the trail–territory system: connection between important places; placement in important habitat to allow access to hunting areas; and minimising the difficulty of travel and navigation.”

• cites Laden (1992)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. It may be too vague to check against evidence. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.

Individuals from other subsistence-level societies who must forage over long distances on various challenging surfaces probably face similar energetic penalties owing to adjusted kinematics.

“Individuals from other subsistence-level societies who must forage over long distances on various challenging surfaces (e.g. brushland, rocky terrain, snow/ice) probably face similar energetic penalties owing to adjusted kinematics, and such costs should be considered in estimates of daily energy expenditure related to walking.”

Probably not a substantial claim. It may state two separate claims as one.

Hunting and gathering has been the sole mode of subsistence for most of our species' existence, and recent hunter-gatherer populations have been found to walk 6-19 km per day.

“Hunting and gathering has been the sole mode of subsistence for most of our species’ existence, and recent hunter–gatherer populations have been found to walk 6–19 km per day (Leonard & Robertson, 1997a; Wood et al., 2021), much of which is likely to be on irregular surfaces.”

• cites Leonard & Robertson, 1997aNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Wood et al., 2021 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

Probably not a substantial claim. It may state two separate claims as one.

For all models, residual plots and q-q plots were inspected to assess model residual homoscedasticity and normality, and these criteria were satisfied for all variables.

“For all models, we inspected residual plots and q–q plots to assess model residual homoscedasticity and normality, respectively. For all variables these criteria were satisfied, and therefore we performed likelihood ratio tests to test for significant model effects.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Post-hoc pairwise contrasts between walking conditions were conducted with a Holm-Bonferroni p-value correction.

“For models where significant differences in walking conditions were detected, we used the ‘lsmeans’ package (Lenth, 2016) to conduct post-hoc pairwise contrasts between walking conditions, with a Holm–Bonferroni p-value correction.”

• cites Lenth, 2016 sourceNot checked — no full text of the source

Probably not a substantial claim.

Human bipedal walking is considerably less expensive than quadrupedal or bipedal walking in other primates.

“Upright bipedal walking has long been argued to represent an adaptation for greater walking economy (Rodman & McHenry, 1980), as human bipedal walking is considerably less expensive than quadrupedal or bipedal walking in other primates (Nakatsukasa et al., 2004; Sockol et al., 2007).”

• cites Nakatsukasa et al., 2004 sourceNot checked — no full text of the source
• cites Sockol et al., 2007 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

It may state two separate claims as one.

We could not quantify kinematic variability between steps for a given terrain type, and thus could not compare the relative amounts of variability caused by walking in terrains like unbroken forest.

“One consequence of this limitation was that we could not quantify kinematic variability between steps for a given terrain type, and thus could not compare the relative amounts of variability caused by walking in terrains like unbroken forest, which we would expect to be high based on previous studies of natural irregular terrains (e.g. Matthis et al., 2018).”

Probably not a substantial claim. The authors may not put it forward as true. The paper’s conclusions may not depend on it.

The evolution of economical bipedalism could have helped facilitate the initial adoption of hunting and gathering foraging strategies.

“These findings have led some to argue that the evolution of economical bipedalism could have helped facilitate the initial adoption of hunting and gathering foraging strategies (Leonard & Robertson, 1997b; Kraft et al., 2021).”

• cites Leonard & Robertson, 1997bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Kraft et al., 2021 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it.

In our previous study of forest walking, we found shorter average step lengths over the full transect.

“which stands in contrast to the shorter average step lengths over the full transect that we found in our previous study of forest walking (Venkataraman et al., 2018).”

• cites Venkataraman et al., 2018 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

Probably not a substantial claim.

Upright bipedal walking has long been argued to represent an adaptation for greater walking economy.

“Upright bipedal walking has long been argued to represent an adaptation for greater walking economy (Rodman & McHenry, 1980), as human bipedal walking is considerably less expensive than quadrupedal or bipedal walking in other primates (Nakatsukasa et al., 2004; Sockol et al., 2007).”

• cites Rodman & McHenry, 1980 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

We were limited in the range of surfaces we could investigate and did not quantify mechanical properties or other terrain characteristics such as obstacle height in the forest.

“While the results of this study provide an interesting, preliminary picture of the kinematic adjustments that are necessary when walking in unbroken forest, we were limited in the range of surfaces we could investigate and did not quantify mechanical properties or other terrain characteristics such as obstacle height in the forest.”

Probably not a substantial claim.

Step-to-step variability is known to increase walking costs.

“Step-to-step variability is known to increase walking costs (O'Connor, Xu, & Kuo, 2012), and thus is another factor that could make walking on natural terrains such as those in forests more energetically expensive.”

• cites O'Connor, Xu, & Kuo, 2012 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

Probably not a substantial claim.

We were restricted to measuring sagittal plane motion in this study.

“Thus, we were restricted to measuring sagittal plane motion in this study.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The likely explanation for this discrepancy is that participants took longer steps to avoid small impediments in the particular segment of the transect that we recorded for this study.

“The likely explanation for this discrepancy is that participants took longer steps to avoid small impediments in the particular segment of the transect that we recorded for this study.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Similar observations have been made for the Mbendjele hunter-gatherers, also of the Congo Rainforest.

“Similar observations have been made for the Mbendjele hunter–gatherers, also of the Congo Rainforest (Jang et al., 2019).”

• cites Jang et al., 2019 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

These errors should not have been systematic across conditions, and they are likely to have been small, since offsets between camera view and walking route were on average 0.9° in a subset of trials (N = 18) where we could calculate the offset angle.

“These errors should not have been systematic across conditions, and they are likely to have been small, since offsets between camera view and walking route were on average 0.9° in a subset of trials (N = 18) where we could calculate the offset angle.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Step-to-step variability is another factor that could make walking on natural terrains such as those in forests more energetically expensive.

“Step-to-step variability is known to increase walking costs (O'Connor, Xu, & Kuo, 2012), and thus is another factor that could make walking on natural terrains such as those in forests more energetically expensive.”

Probably not a substantial claim. It may be too vague to check against evidence. It may state two separate claims as one.

This scenario has important implications for theories that relate hominin ecology to the evolution of economical bipedalism, as well as for the energy requirements of foraging in modern humans who rely on long daily travel distances for subsistence, such as hunter-gatherers.

“This scenario has important implications for theories that relate hominin ecology to the evolution of economical bipedalism, as well as for the energy requirements of foraging in modern humans who rely on long daily travel distances for subsistence, such as hunter–gatherers.”

Probably not a substantial claim. It may state two separate claims as one.

We were limited to a single camera view, and therefore could not capture three-dimensional kinematics.

“Finally, and relatedly, we were limited to a single camera view, and therefore could not capture three-dimensional kinematics.”

Probably not a substantial claim. It may state two separate claims as one.

We were restricted to capturing motion from a single, short (~2 metres) segment of the forest transect, and therefore could only assess kinematic adjustment in response to the particular obstacles/impediments in this segment.

“First, we were restricted to capturing motion from a single, short (~2 metres) segment of the forest transect, and therefore could only assess kinematic adjustment in response to the particular obstacles/impediments in this segment.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Slight offsets in the angle of the camera view relative to the ground may have caused errors in some of our measurements.

“We set our camera views parallel to the walking route marked by flags to define an x-axis that was parallel to the ground, but it is possible that slight offsets in the angle of the camera view relative to the ground caused errors in some of our measurements.”

Probably not a substantial claim. It may be too vague to check against evidence.

By studying locomotion in a diversity of human populations, especially those who regularly travel through complex natural environments, we may better understand the evolution of bipedalism.

“Thus, by studying locomotion in a diversity of human populations, especially those who regularly travel through complex natural environments, we may better understand the evolution of bipedalism.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

We encountered difficulty in establishing a real-world coordinate system using a single camera.

“A related problem that we encountered was difficulty in establishing a real-world coordinate system using a single camera.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Even more open natural terrains often include obstacles like rocks and vegetation that can impede camera views of foot markers, preventing the measurement of many kinematic variables.

“While the problem of marker obstruction was particularly significant in the forest, even more open natural terrains often include obstacles like rocks and vegetation that can impede camera views of foot markers, preventing the measurement of many kinematic variables.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Matthis et al. (2018) observed shorter steps on average but greater step length variability in people walking on rocky terrain compared with even terrain.

“This scenario would be consistent with the findings of Matthis et al. (2018), who observed shorter steps on average but greater step length variability in people walking on rocky terrain compared with even terrain.”

• cites Matthis et al., 2018 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

Probably not a substantial claim. It may state two separate claims as one.

Reconstructions of hominin locomotor energetics that use standard laboratory-based measures of human walking costs may be underestimating the actual energy expenditure necessary for foraging and overestimating the energetic advantages of human bipedalism.

“If this hypothesis is true, reconstructions of hominin locomotor energetics that use standard laboratory-based measures of human walking costs may be underestimating the actual energy expenditure necessary for foraging and overestimating the energetic advantages of human bipedalism.”

Probably not a substantial claim. It may be too vague to check against evidence. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.

In any 'natural' terrain no single short segment that can be captured on video will provide a representation of the full diversity of surface characteristics that could require alterations in gait kinematics.

“Indeed, in any ‘natural’ terrain no single short segment that can be captured on video will provide a representation of the full diversity of surface characteristics that could require alterations in gait kinematics.”

Probably not a substantial claim. It may be too vague to check against evidence. The paper’s conclusions may not depend on it.

Our findings are preliminary.

“Nevertheless, given these different limitations, we emphasise that our findings are preliminary, and that further research using more sophisticated equipment is needed to study walking over longer distances and to quantify more kinematic variables to further characterise gait adjustments on different terrains.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Validation studies have indicated that IMU systems produce reasonably accurate measurements of 3D kinematics during walking when compared with camera-based optical motion capture systems.

“Validation studies have indicated that IMU systems produce reasonably accurate measurements of 3D kinematics during walking when compared with camera-based optical motion capture systems (Al-Amri et al., 2018; Cho et al., 2018).”

• cites Al-Amri et al., 2018 sourceNot checked yet
• cites Cho et al., 2018 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

It may state two separate claims as one.

Marker obstruction prevents the measurement of continuous kinematics across a stride, and so within-stride variation also cannot be assessed.

“Marker obstruction also prevents the measurement of continuous kinematics across a stride, and so within-stride variation also cannot be assessed.”