Aрpellant alleges numerous trial errors in this appeal from an adverse award in a personal injury action. Finding his contentions without merit, we affirm the lower court’s order.
At about 11:00 p.m. on the snowy night of February 13, 1978, appellant’s automobile struck appellee’s garden tractor head-on as appellee was plowing snow from his driveway near the berm of the highway. The exact locations and speeds of the vehicles were disputed. In the collision, appellee suffered broken bones in the right side of his face, his pelvis, and both legs, and the choke handle of the tractor was imbedded in his abdomen. After seven weeks in casts immobilizing his pelvis and both legs, a subsequent operation to remove the choke handle, and a period of convales *572 cence, appellee was diagnosed to have suffered a 30% permanent disability of his legs and a permanent disfigurement of the right side of his face. Upon returning to work, appellee discovered he had lost the ability to duck in or around machinery or to stand for prolonged periods as required by his customary job as a printing press operator and repairer, but he was able to obtain another less strenuous, but nearly equally remunerative, job at a grocery store. On August 5, 1980, he commenced this action in trespass against appellant. 1 Following a trial, at which appellee introduced a witness testifying on the issue of damages who had not been identified in pre-trial discovery, the jury found appellant 80% negligent and appellee 20% negligent in causing thе accident, assessed appellee’s damages at $80,000, and thus awarded him a net verdict of $64,000. 2 Following denial of post-verdict motions, the lower court entered judgment in favor of appellee on September 14, 1981. Thirty-six days later, on October 20, 1981, during the pendency of this appeal, the lower court molded the verdict to add the 10% per annum pre-award delay damages required by Pa.R.Civ.P. 238.
Appellant contends that the lower court erred in admitting a co-worker’s testimony because her identity had not been disclosed in response to interrogatories. We find that the error, if any, was harmless. Although the challenged witness’s testimony helped support appellee’s damage claim, and may have bolstered his credibility by corroborating some of his testimony, the lower court’s finding that the proffered testimony was “rather innocuous” in the context of this trial is well-supported. Expert witnesses had described appellee’s actual injuries. Appellee had already testified about his working conditions and ability to perform his рrinting job. (N.T. at 25-27, 72), and appellant did not dispute the facts asserted, (N.T. at 92-94). The
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substance of the challenged witness’s testimony that appellant was well respected and had good job prospects was already in evidence through appellee’s undisputed testimony about his long service, (N.T. at 26), and appellant’s eliciting from him that he had resumed the job after the accident at a higher rate of pay, (N.T. at 94). Any prejudice from surprise was minimal. Appellee had disclosed in discovery his intent to call an “employment specialist,” and had revealed the name and address of his employer and the nature of his job as a printing press operator and repairer. Although appellee never disclosed the precise identity of this witness as he should have,
see
Pa.R.Civ.P. 4007.4, that the witness was a co-worker rather than the promised specialist did not appreciably burden appellant. Sidebar discussion revealed that appellant was aware that the witness was appellee’s aunt, and appellant was able to use this relationship on cross-examination. (N.T. at 131-32). In addition, the court found no indication of bad faith or attempt to mislead in presentation of this witness. Even under a strict reading of the procedural rules, holding that the presentation of a non-disclosed witness was
per se
error under Pa.R.Civ.P. 4019(i), a new trial would not be warranted here. The erroneous admission of evidence is not grounds for a new trial if the particular facts it tended to prove were clearly established by other competent evidencе, especially if the facts were not disputed,
see Coons v. McKees Rocks Boro.,
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Appellant contends next that the lower court erred in permitting appellee to answer, over objection, a leading question posed him on direct examination. We hоld the lower court acted within its discretion in permitting an answer to the question. The rule proscribing leading questions by the party calling a witness “is liberally construed in modern practice, with a large measure of discretion in the court to permit parties to elicit any material truth without regard to the technical considerations of who called the witness. It is a discretion not susceptible of exactly defined limits beforehand, but to be exercised in the interests of justice and a fair trial under the circumstances as they arise.”
Commonwealth v. Gurreri,
197 Pa.Superior Ct. 329, 332-33,
[Appellee’s Counsel]: Now, have you tried sitting down to rest your legs?
[Appellant’s Counsel]: Objection, Your Honor, this is becoming very leading.
The Court: Overruled.
[Appellee]: Yes.
N.T. at 74. Permitting this isolated leading question after a discussion of appellee’s employment circumstances was within the lower court’s discretion, and, accordingly, we will not disturb its decision.
Appellant contends that the lower court erred in refusing to instruct the jury on аssumption of risk. We find, however, that such an instruction was unnecessary. The facts most favorable to an assumption of risk charge are as follows: While plowing snow, appellee partially obstructed the left side of the highway with his garden tractor. He saw appellant’s headlights bearing down upon him as they became visible around the bend 600-800 feet away. Think *575 ing the car belonged to a practical jokester friend, appellee proceeded without trying to evade the oncoming car, hoping that it wоuld avoid him. The car did not, and appellee was severely injured in the resulting collision. (N.T. at 95).
Assumption of risk may be implied from a plaintiffs conduct under the following standard:
[A] plaintiff who fully understands a risk of harm to himself ... caused by the defendant’s conduct ... and who nevertheless voluntarily choses to enter or remain ... within the area of that risk, under circumstances that manifest a willingness to accept it, is not entitled to recover for harm within that risk.
Restatement (Second) of Torts, § 496C (1965).
Accord, Rutter v. Northeastern Beaver County School District,
[Djecedent was guilty of negligence as a matter of law. He chose a place of danger in preference to one of comparative safety and by reason of his position was injured. His so doing аmounted to an assumed risk and recovery must be denied.
Id.,
Such an approach is proper because of the nature of the defense. Assumption of risk and comparative negli
*577
gence may sometimes overlaр because certain conduct may exhibit all the elements of both.
See Bortner v. Gladfelter, supra; Takach v. B.M. Root Co.,
279 Pa.Superior Ct. 167,
A particularly difficult element of the defense is in defining “circumstances that manifest a willingness to accept” the risk. Restatement (Second) of Torts, § 496C. The nature and purposes of the defense help courts in defining these circumstances. Assumption of risk “reflects the individualism of the common law” which allows people to make their own choices and does not undertake to “proteсt [them] from the effects of [their] own ... voluntary actions.”
Rutter v. Northeastern Beaver County
*578
School District, supra
Thus, the essence of the assumption of risk defense is not fault but that the plaintiff changed his position. Before the injury, he intelligently acquiesced in a known danger and abandoned his right to complain, but after-wards, seeks to assert the claim he had waived.
See Jones v. Three Rivers Management Corp., supra.
To imply such waiver from conduct and circumstances alone can be a source of “misapprehension and confusion” and “frequent misapplication.” W. Prosser, Law of Torts, at 445 (4th ed. 1971). Aware of this danger, our Court announced, even before comparative negligence, that it would take a “restrictive attitude” toward the circumstances from which the assumption of risk defense might be implied.
Fahringer v. Rinehimer,
283 Pa.Superior Ct. 93, 98-99,
[T]he practical difference [between assumption of risk and contributory negligence] is in the degree of proximity to the particular harm. The preliminary conduct of getting into a dangerous employment or relation is said to be accompanied by assumption of the risk. The act more *579 immediately leading to a specific accident is called negligent.
Schlemmer v. Buffalo, Rochester & Pittsburg Ry.,
Appellee, like the pedestrian who steps out in the middle of the block, voluntarily placed himself in a dangerous situation by partially obstructing traffic with his snowplow. He may have been foolhardy and negligent, but he cannot be said to have consented that oncoming drivers abandon their duty of care to keep their vehicles under sufficient control in the snowy conditions to avoid a collision. In the moments when appellant’s car approached him, appellee made another choice. He refrained from evasive acts because he thought the car bearing down on him belonged to a practical joking friend. In those moments he had become aware of appellant’s specific actions. Yet these last minute decisions, of the sort that might be heavily influenced by an erroneous guess as to the speed or path of the оncoming car, are not those that indicate an intelligent acquiescence to the possible life-or-limb consequences. They are not made “under circumstances that manifest a willingness to accept” the risk. Restatement (Second) of Torts, § 496C. Thus, our law does not require that these facts be submitted to a jury as an assumption of risk defense. Rather, appellee’s entire course of conduct is properly analyzed as possible negligence, and was thus correctly submitted to the jury as possiblе comparative negligence. Accordingly, we affirm the lower court’s refusing the assumption of risk instruction.
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Appellant contends next that the lower court’s instruction to the jury on comparative negligence was insufficient. This contention lacks merit. A trial judge has wide latitude in charging the jury, and may use any particular language provided the language used adequately and fully conveys to the jury the law applicable to the facts of the case.
Albert v. Alter,
252 Pa.Superior Ct. 203,
Appellant contends that the assured clear distance ahead rule was inapplicable, and thus the lower court erred in charging the jury on it. We find that the rule was applicable, and the court’s instruction proper. Under the assured clear distance ahead rule, a driver must keep his vehicle under such control that he can always stop within the distance that he can clearly see, a distance that will vary according to the visibility and the attending circumstances.
Koelle v. Philadelphia Electric Co.,
*582
Appellant contends the lower court erred in instructing the jury to consider appellee’s mental anguish and pain as an element of damages because the only evidence concerned appellee’s physical pain. This contention is frivolous. Although a person who suffers only mental injury may be limited regarding his tort remedies,
see Sinn v. Burd,
Appellant contends that the record contains insufficient evidence for the lower court’s instructions that the jury determine аppellee’s loss of future earnings and consider: the probable increase then decrease of his earnings as he aged, his probable inability to get future jobs as a result of this accident, and his manner of living as it might affect his future productivity and life expectancy. We are satisfied that the record adequately supports these instructions. An injured plaintiff is compensated for the loss in future earning capacity—the lowering of his economic horizons—whether the loss in capacity actually reduces his earnings or not, and it is for the jury to decide the extent and duration of the loss.
McCaffrey v. Schwartz,
Appellant contends finally that the lower court erred by acting outside the 30-day period after entry of judgment when it modified the verdict to reflect pre-award interest under Pa.R.Civ.P. 238. We find the lower court’s action was correct and timely. A lower court may not ordinаrily modify an order beyond the thirtieth day after its entry, except as otherwise provided by law. 42 Pa.C.S.A. § 5505; Pa.R.A.P. 1701. For instance, the court may correct obvious or patent mistakes after that 30-day limit has expired.
Commonwealth v. Cole,
Affirmed.
Notes
. Appellee’s medical expenses and certain work-loss benefits had already been paid by his No-fault insurance carrier.
. Appellee’s wife was awarded $2,500, reduced to $2,000, for loss of consortium.
.
See DeFonde v. Keystone Valley Coal Co.,
.
See McDevitt v. Terminal Warehouse Co.,
304 Pa.Superior Ct. 438,
. We need not here address the exceptional case in which a defendant, during the litigation, raises a legitimate question as to when and whether the cause of action accrued within the year immediately preceding the complaint, or as to whether one of the limited exceptions to the rule applies. See Pa.R.Civ.P. 238.
